MS 544 PART 5 2001 Timber Joints

8/13/2019 MS 544 PART 5 2001 Timber Joints

1/50

MS 544 : PART 5 : 2001

CODE OF PRACTICE FOR STRUCTURALUSE OF TIMBER :PART 5 : TIMBER JOINTS

ICS : 91.080.20

Descriptors : permissible stress design, timber joint, solid timbe fabricated with mechanical fasteners,joint groups, timber grade, working loads, permissible loads, spacing, edge, end distances

MALAYSIAN

STANDARD

Copyright

DEPARTMENT OF STANDARDS MALAYSIALicencedtoUNIVERSITIMALAYSIA

PAHANG(

UMP)/Downloadedon:01-Jul-

2009/Singleuserlicenceonly,copyingandnetworkingprohib


2/50

DEVELOPMENT OF MALAYSIAN STANDARDS

The Department of Standards Malaysia (DSM) is the national standardisation

and accreditation body.

The main function of the Department is to foster and promote standards,

standardisation and accreditation as a means of advancing the national

economy, promoting industrial efficiency and development, benefiting the health

and safety of the public, protecting the consumers, facilitating domestic and

international trade and furthering international cooperation in relation to standards

and standardisation.

Malaysian Standards are developed through consensus by committees which

comprise of balanced representation of producers, users, consumers and others

with relevant interests, as may be appropriate to the subject in hand. These

standards where appropriate are adoption of international standards. Approval of

a standard as a Malaysian Standard is governed by the Standards of Malaysia

Act 1996 (Act 549). Malaysian Standards are reviewed periodically. The use of

Malaysian Standards is voluntary except in so far as they are made mandatory by

regulatory authorities by means of regulations, local by-laws or any other similar

ways.

The Department of Standards appoints SIRIM Berhad as the agent to develop

Malaysian Standards. The Department also appoints SIRIM Berhad as the agent

for distribution and sale of Malaysian Standards.

For further information on Malaysian Standards, please contact:

Department of Standards Malaysia OR SIRIM BerhadLevel 1 & 2, Block C4, Parcel C 1, Persiaran Dato' MenteriFederal Government Administrative Centre P.O. Box 7035, Section 2

62502 Putrajaya 40911 Shah Alam

Malaysia Selangor D.E.

Tel: 60 3 88858000 Tel: 60 3 5544 6000Fax: 60 3 88885060 Fax: 60 3 5510 8095http://www.dsm.gov.my http://www.sirim.my

Email: [email protected]

PAHANG(

UMP)/Downloadedon:01-Jul-

2009/Singleuserlicenceonly,copyingandnetworkingprohib


3/50

M S 544: PART 5 : 2001

CONTENTSPage

Commit tee representation ivForeword v i

Scope 2 Refe renced documen ts 3 Jo in t groups 24 T imbe r g ra de 35 Ant i-corrosion treatment 36 Tendency to split 37 Eccentr ic joints 48 Shear stress in th e jointed member 49 Nailed joints 510 Screwed joints 121 1 Bolted joints 1512 Coach screws 2513 Split-ring connectors 2814 Shear plate connectors 3 7

Tables Group classif icat ion of t imbers for us e in joint design 22 Dry basic s ing le shea r lateral loads fo r one nail inserted at r igh t ang les to

s ide g ra in 53 Dry basic s ing le shea r lateral loads for on e nail in a plywood to t imber joint 64 Modif icat ion factor k 1 for durat ion of loading for different fasteners 9

LicencedtoUN

IVERSITIMALAYSIAPAHANG(

UMP)/D

ownloadedon:01-Jul-2009/Singleuser

licenceonly,copyingandnetworkingproh

ib


4/50


5/50

M S 544: PART 5 : 2001

CONTENTS continuedPage

23 End distances for split-ring and shear-plate connectors 322 4 Edge d istances for split-ring and shear-plate connectors 3225 Spac ing modif icat ion factor, k~or split-ring and shear-plate connectors 3326 End distances modif icat ion factor, k~or split-ring and shear-plate connectors 3527 Loaded, e dge distances modif icat ion factor, k D fo r split-ring and shear-plate

connectors 3628 Sizes of shear-p la te connectors and minimum sizes of washers 3729 Dry basic loads for one shear-plate connector unit 4030 Limiting values fo r permissible loads on one shear-plate connector unit 4 1Figures Shear s tress in th e jo in ted membe r 42 Illustration of a longitudinal and rotationa l joint 83 Graph of Hankinson formula 204 Spacing, edge and end d is tances for bo lted jo in ts 235 Coach screw 266 Timber thicknesses and fastener lengths for coach screws 267 Spacing, edge and end distances fo r split-ring and shear-plate connectors 368 Dimension of c i rcu lar recesses for shear-plate connector units conforming

to BS 1 5 7 9 38

III

LicencedtoUN


UMP)/D



ib


6/50

M S 544: PART 5: 2001

Th e Bu ild in g a nd C iv il Engineering Industry Standards Commit tee ISC D) under whose superv is ion this MalaysianStandard was developed , compr ises representa t ives from the following Government Min is tr ie s, T rade , Commerceand Manufacturing Associat ions, and Scientif ic and Professional Bodies:Association of Consult ing Engineers MalaysiaConstruct ion Industry Development Board MalaysiaDepartment of Standards Ma laysi aDepartment ofOccupat iona l Safety and HealthJabatan Bornba dan PenyelamatPertubuhan Aki tek MalaysiaMaster Bui lders Associat ion MalaysiaMinistry ofHousing an d Local Government ous ing Depar tment)Ministry of Works Public Works Department)Th e Institution of Eng ineers , Ma lays iaUniversi ti Teknolog i MalaysiaTh e development o f th is Malaysi an Standa rd is under the supervision of the following representat ives of th e C IDBStandard Commit tee:Ir . Mohamed b in Mohd Nuruddin Genera l Manager Technology Development DivisionMegat Kamil Azmi bin Megat Rus Kamarani Senior Manager S tanda rd and Quality UnitPuan Zainora bt Zaina l Manager Standard and Qua lit y Un itPuan Hanishahani Othman Th e Secretary of CIDB Standard Commit teeThe Technical Committee on Structural Use of Timber which developed this Malaysian Standard consists of thefollowing representat ives:Dr. Abdul Rashid bin H ]. Ab . Malik Chairman)

ommittee represent tion

Puan Hanishahani Othman Secretary)Tuan Hj. Mohd Shuka ri bin MidonEncik Hilmi bin Md. TahirEncik Chow Wah/Puan Dang Anom Md. ZinProf. Madya Dr . Sabaruddin bin Mohd.Prof. Dr. Zainai bin Mohamed/Dr. Abd. Latif bin SalehP ro f Madya lr. Dr . Mohd Zamin bin JumaatDr. Mohd Ariff bin JamaludinEnc ik Mohd No r Zamri bin Mat AminI r . Y ap C hin TianTuan H] . Wahab bin Abdul Razak.Dr . Pe te r Kho Chin SengEncik La ll S ingh GillE nc ik Moh amad Omar bin Mohamad Kha idz ir

Fores t Research Inst itute MalaysiaConstruction Industry Development Board Ma laysi aFores t Research Institute MalaysiaJabatan Kerja Raya MalaysiaJabatan Perumahan NegaraUniversi t i Sains MalaysiaUniversi t iTeknologi MalaysiaUniversi t i MalayaUniversi t i Putra MalaysiaMalaysian Timber Indus try BoardTimber Trade Federation MalaysiaGeneral Lumber Fabricators an d Builders BhdSarawak Timber AssociationMalays ian Wood Mould ing and Joinery Counc ilForest Research Institute Malaysia

ivLicencedtoUN


UMP)/D



ib


7/50

MS544: PART5: 2001

ommittee represent tion continuedThe Working Group on Timber Joints which developed this Ma lays ian S tandard consists of the followingrepresentat ives:Tuan H ]. Mohd Shukar i bin Midon Chairman) Forest Research Institute MalaysiaPuan Hanishahani Bte Othman Secretary) Construction Industry Development Board MalaysiaEncik Hilmi bin Md. Tahi r Jabatan Kerja Raya MalaysiaI r . Yap Chin han Timber Trade Federation MalaysiaDr. Peter Kho Ch in Seng Sarawak Timber AssociationMr. Nicolas Roulant General Lumber Fabricators a nd Build er s BhdProf. Madya I r . Dr . Mohd Z am in bin Jumaat Universiti MalayaDr. Mohd. A riff bin Jamaludin Universi t i Putra MalaysiaYM . E ng ku Abd ul R ahma n bin Chik Syntek Sdn. BhdEncik C hu Y ue PunEncik Mohd Nor Zamri bin Mat Amin Malaysian Timber Industry Board

V

LicencedtoUN


UMP)/D



ib


8/50

MS544: PART 5:2001

FOREWORDThis Malaysian Standard was dev elo pe d by the Techn ica l Committee on Structural Use ofTimber establ ished at th e Cons truc tion Indus try Deve lopment Board Malaysia CIDB) underthe au tho rity of th e Building and Civil Engineering I ndustry S tandards Commi ttee .01DB is the Standards-Writ ing Organisat ion SWO ) appoin te d by S IR IM Berh ad to develops tanda rds fo r the construct ion industry.In the deve lopment of this standard, the following re fe rences were referred to:a) BS 5268: Part 2: 1996 , Code of pract ice for perm iss ib le s tress des ign , materials

and workmanship; andb) AS 1720.1-1 988 , SAA T imber s truc tu res code: Part Design methods.MS 544 consists of the following parts and sections, under the general title, Code of pract icefor structural use of t imberPart GeneralPart 2 Permissible s tress design of solid t imberPart 3 Permissible s tress design of glued laminated t imberPart 4 T imber panel productsSect ion 1: Structural plywood

Section 2: Marine plywoodSect ion 3: Cement bonded par ti cleboardSect ion 4: Oriented strand boardPart 5 Timber jointsPart 6 Workmanship, inspect ion and maintenancePart 7 TestingPart 8 Design, fabricat ion and installation of prefabricated t imber for roo f t russesPart 9 Fire resistance of t imber structuresSect ion Method of calculat ing f ire resistance of t imbe r membersPart 10 Preservat ive treatment of st ruc tural t imbersPart 1 1 Recommendat ion for th e calculation basis for span tablesSect ion Domest ic f loor joistsSect ion 2 Ceil ing joistsSect ion 3 Ceil ing bindersSection 4: Domest ic raftersPart 12 Laminated veneer lumber for structural appl icat ion.Compl iance with a Malaysian Standard does not of itself con fe r immun ity from legalobl igations.

V i

LicencedtoUN


UMP)/D



ib


9/50

MS544: PART5: 2001

CODE OF PRACTICE FOR THE STRUCTURAL USE T IMBER:PART 5 TIMBER JOINTS

1. ScopeThis part appl ies to joints in solid t imber fabricated with mechanica l fasteners descr ibed byMalaysian Standard. These include joints fabricated with the following mechanical fasteners :a) nails;b) wood s crews;c) bolts;d ) coach screws;e) spl it -r ing connectors; andf) shear-p la te connectors.NOTES:1 . Design rules for spec ia l ised and pa ten ted mechan ica l fasteners an d for variants of convent ional fasteners are notincluded in thi s code.2 . This Standard d o e . s not spec if ica lly cover glued t imber-to-timber or t imber-to-plywood connections as occur red infabricated components s uc h a s stressed s kin p anels o r plywood webbed beams. In such cases, joint design ca n bebased on t he timbe r components in the connection, p ro vid ed t ha t the joint is f ab rica ted usi ng a rigid, durableadhesi ve. Phenoli c type adhes ives meet t hese requirements. The des ign of fabr ica ted components compr is ing gluedconnect ions is therefore based on the fact t ha t w ith correct bonding practice and quality control, a joint is developedin wh ic h th e adhesive bond s treng th and durability will be superior to t he componen ts compri si ng the joint. Referencemay be made to AS 1720 . 1 : 1988 , Appendix D2 fo r information on methods for assessing the deformation of joints.

2. Refe renced documen tsThe following referenced documents contain provisions which, through reference in this text,constitute provision of this Malaysian S tandard. For dated references, where there aresubsequent amendments to , or revisions of, any of these publications th e Malaysian Standardsh all be amended or revised accordingly. For undated references, th e la tes t ed it ion of thepubl icat ion re fe r red app ly .MS 544: Part 2: Permissible s tress des ign of solid t imberMS 5 44 Part 4: Timber pane l products:Section 1: Structural plywood

Section 2: Marine plywoodNZS 3603: 1981 Code of pract ice for t imber design Section 4 JointsTimber design handbook-Malaysian Forest Record No. 42 FRIMStructura l t imber jo in ts-Malaysian Forest Record No. 3 2 FRIMAS 1 39 3 Coach s crews metric series) with ISO hexagon heads)AS 1 4 7 6 Metric wood screwsAS 2 3 3 4 Steel nails Metric series

LicencedtoUN


UMP)/D



ib


10/50

M S 544: PART5: 2001

AS 1111 ISO metric hexagon bo lt s and screws Products grade CBS 3 73 Methods of te sting sma ll clear spec imens of t imberBS 1 5 7 9 Connectors for t imberASTM D143 Standard methods of testing small clear spec imens of t imberA ir seasoning propert ies of some Ma lays ian timber s -Ma la ys ian Fore st Se rv ic e Trade LeafletNo.41 MTIBThe strength propert ies of some Malays ian t imbers Malaysian Fores t Se rv ic e Trade LeafletNo. 34 MTIB

3. Joint groupsFor the purpose of joint design, t imber species have been c lassified into five jo in t g roups : JiJ2 , J3 , J4 and J5 . The joint group classifications for spec i fic t imbers are shown in Table 1.

Table 1. Group classification of t imbers for use in jo int des ignJointgroup Strengthgroup Timbers

J1 SG1 Balau Bitis Chengal Penaga

J2 SG2/SG3Bekak Belian Balau, redAgoho Delek Kern pas KeranjiDedaru Kembang semangkok Kekatong KulimKelat Mertas Mata ulat PerahMerbatu Penyau Petaling Surian batuPauh k ijang TualangRanggu

J3 504 Berangan Dedali Derum GiamKapur Kasai Keruntum MempeningMalabera Merant i bakau Merawan MerbauMerans i Nyalin Perupok PunahMerpauh Resak S impohRengas

J4 SG5 Alan bunga Babai Balik angin bopeng Biri tangorBrazil Nut Gerutu Kedondong Kayu kundurKungkur Kelendang Keruing KetapangMerant i , dark red Melunak Mempisang MengkulangMeranti white Nyatoh Petai PenarahanRamin Rubberwood Sepetir Sen gkuangTembusu Teak

J5 SG6 /SG7 Ara Bayur Batal DurianDamar minyak Geronggang Jelutong JongkongJenitri Kasah Laran Merant i , light re dMachang Medang Melantai / Kawang Meranti ,yellowMersawa Pelajau Pulai SesendokTerap Terentang

2LicencedtoUN


UMP)/D



ib


11/50

M S 544: PART 5 2001

Where joints comprise more than one species of t imber, th e design load to be used in th eabsence of other informat ion is that appropr ia te to the weakest specie s in the joint.

4~ T imbe r g radeNo al lowance for th e various grade of t imber ha s bee n made in design data for fasteners.Design loads for joints ha ve be en based on the assump tion that there are no loose knots,severe sloping grain, gum veins, gum or resin pockets, pith, hole s o r sp lits near any fastener.Accordingly, all of these de fec ts sha ll be avoided at fastener locations.

5 . Anti -corrosion trea tmentThe loads specif ied for na ils , sc rews, bolts and coach screws app ly to fa stene rs th a t a re nottreated against corrosion. Some forms of anti-corrosion treatment may affect fastenerperformance.The loads specif ied for t imber c onnec to rs apply to fasteners that a re tre ate d a ga in stco rros ion . Fas teners used in wet t imber or in t imber, which will be exposed to th e wetexposure condit ion, should be non-corrodable or are tr ea ted by an ant i-corros ive process.

6. Tendency to spli tSpec ial precautions shal l be specif ied in th e us e of t imber that has a tendency to split to anex ten t t ha t may be detrimental to connec tor s trength. In th e absen ce of o ther gu idance, thecriterion for tendency to split shall be based on th e parameter c x defined by :

where,c is th e tangential shrinkage, in ; andy is th e tangential c leavage st rength o f g reen t imber, in Newton per mill imetre

N /mm) , as measured by BS 3 73 or ASTM D143 .Spec ies for which c x > 0 .8 often have a high tendency to spli t, par t icu lar ly in exposedlocations; species for which c x < 0.55 may be considered to have a negligible tendency to split.NOTES:1 . Information on shrinkage and c leavage for spec if ic spec ies ca n be obtained from the fo llow ing:a Malaysian Forest Servi ce T rade Leaflet No : 41 : Air-seasoning properties of some Ma laysi an timbers.b Malaysian Forest Serv ice Trade Leaflet No : 34 : The strength properties of some Malays ian t imbers .2 . It will be found that mos t ha rdwoods that have a basic density of less tha n 7 00 kg/m3 will have splitting parameterc~>.8 ; mos t rainforest hardwoods of higher density have a spl it ting parameter a < 0.8.

3

LicencedtoUN


UMP)/D



ib


12/50

M S 544: PART5 :2001

7 Eccentr ic jointsWhen it is impracticable to ensure that all the membe rs meeting at a joint are arrangedsymmetrical ly, with their centre l ines intersect ing on a common a xis whic h is also th e axis ofresistance of the fasteners or group of fasteners, th e comb ined e ffe cts of pr imary s t ressesand seconda ry stresses due to the result ing bending and shear s tress sha ll be checked.

8. Shear stress in the jo inted memberThe effect ive cross-section of a jo in ted member s ho uld b e us ed when calculat ing its strength.The method of de te rm ining the e ffec tive cross-sect ion is given in the appropr ia te clauses foreach ty pe of fastener. In addit ion, it should be shown th at th e shear s tr es s condition shown inFigure is satisfied in th e jointed member.

Unloaded edge

V = Fsina3V2 bhewhere,

Figure 1. Shear stress in th e jointed member

shall not exceed C adm

V is the shearing force at the sect ion;B is the thickness of th e member;

hI

4LicencedtoUN


UMP)/D



ib


13/50


14/50

M S 544: PART 5 2001

Table 3. Dry basic s ing le shea r la tera l load fo r one n ai l i n a plywood to t imber jointNominalplywoodthickness

m m

Nail m m~_________

Penetration of nail totimber~mm Basic Lateral load N fo r t imber i n group

Diameter Minimumlength Standard Minimum JI J2 J3 J4 J56 2 .63 .03 .33 .74 . 1

4045455560

3439394955

1 31 5171 92 1

3394264965947 0 1

27033739347 1556

215270315377445

172216252301355

13 516 9197236278

9 2 .63. 03 .33 .74 . 1

4045455560

3 13636465 1

1 31 5171 92 1

342429494597704

273340396474559

218273318380448

17 5219255304358

13817220023928112 2 .63 .03 .33 .74. 1

4045455560

2833334348

1 3151 7192 1

345432502600707

276343399477562

221276321383451

17822225830736 1

1 4 117520324228415 2 .63 .0

3 .33 .74. 1

4045455560

2530324045

131517192 1

348435505603710

279346402480565

224279324386454

1 8 1225261310364

144178206245287

18 2 .63 .03 .33 .74 . 1

4347505662

2529323844

131517192 1

35 1438508606713

282349405483568

227282327389457

184228264313367

1471 8 12092482902 1 2 .63 .03 .33 .7

4 . 1

4650535965

2529323844

1315171 9

2 1

35444 151 1609716

28535240848657 1

230285330392460

1872312 6 7316370

150184212251293

NOTES:1 . Plywood should be s truc tural o r ma ri ne p lywood depending on serv i ce cond it ion , see MS 544: Part 4: Section and 2 .2 . The basic load is based on the standard nail penetration, If the penetration is less than the standard b ut n ot lessthan th e minimum, the basic load should be reduced proportionately. th e penetration is more than the standard, noincrease in basic load is allowed.

6LicencedtoUN


UMP)/D



ib


15/50

M S 544: PART5:2001

9.1 .2 P erm issible loa dsThe permissible load Fadm of a laterally loaded nail shal l be taken to be given by :Fadm k k 2 k 3 k 4 k 6 k 7 Fwhere;k = the fac to r for durat ion of load g iv en in Table 4;k 2 = 1 .0 for dry t imber= .0 for annular ring shank and helical th re ad ed s ha nk nails under allexposure condit ions

= 0 .7 for wet t imber;k 3

= 1 .0 for nails in side grain= 0 .7 for nails in end g ra in ;

k 4 = 1 .0 for nails in s ing le shea r= 0 .9 t imes th e number s of shear p lane , prov ided that each of th e membe r in amultiple shear joint ha s a th ickness of not less than 0 .7 of th e s ta nd ardthickness for po in t s ide member given in Table 2;= 1.25 for nails driven th rough c lose f itting ho les into metal s ide p la tes= .0 for t imber to t imber joint;

k 7 = factor for multiple nailed joints given in Table 5.1 for longitudinal joints andTable 5 .2 for rotational joints; and

F = bas ic work ing load g iv en in Table 2.For long itud ina l joints containing n nails, F~ he des ign lo ad capacity of the jo in t, sh all betaken to be g iv en by

= nFadm

For rotational joints containing n nails, M~ th e des ign in-plane moment capacity of th e joint,shall be taken to be given bynM~ = Fadmrmax~ rj/rma,~f2

1 = 1where;r is th e distance from the P~nail to th e centroid of the nail group; andr m a x is the max imum value of r Longitudinal and rotational joints are illustrated in Figure 2.

7

LicencedtoUN


UMP)/D



ib


16/50

MS 544: PART5:2001

~aI 7

Fn~

a Longitudinal joint

na= 14

k~

b Rotational joint

Figure 2 . Illustration of a longitudinal and rotational joint

~. F,~

M~Circle of rad ius 0 . 7 r

. I i. ~ IN ~ I

~ ~ ~~ III

r max

8LicencedtoUN


UMP)/D



ib


17/50

M S 544: PART5:2001

Table 4 . Modi f ica t ion factor k for duration of loading for different fastenersFastener Dura tion of loading

Long term Medium term Short and very short term

Nails and screws 1 .0 1 .125 1 .2 5

Bolts, coachscrew, split-ringsand shear- plates1 .0 1.25 1 .5

Table 5 . Va lues of factor k 1 7 fo r u se in th e design of multi ple nailCom prising of Table 5.1 and 5.2Table 5.1. For longi tudinal tension joints

and screw jo in ts

Condition of t imberValue of c

Fasteners

Wetry

flal4 f lat 5 f la; = 10 flal 01 .0 0 0 .90 0 .801 .00 0 .94 0 .90 0 .750 .85

NOTE. f laf number of fasterners in e ac h row per in te rfa ce . See F igure 2 a)

Table 5 .2 . For rotational jointsflar=number of nails pe r interface k 7

2510201 0 0 o r g rea te r

1 .001 .051 .101 .151 .20NOTES:fla = number of nails wi th in the circle of radius 0. 7 r m a xr, = distance from ft h nail to centroid o f nail g roupr m a x = maximum value of r See Figure 2 b) .

9

LicencedtoUN


UMP)/D



ib


18/50

MS544: PART5:2001

9.1.3 Spacings, edge and e nd distancesTable 6 provides recommended minimum spac ings, edge and end distances for nails in termsof nail diameter d. For spacings at an angle to th e grain, interpolation by means ofHankinsons formula may be used.NOTE. Fo r timbe r th at has a tendency to sp lit se e C la use 6 ) som e m itiga tion measures such as pre-drilling orincreased spacing are recommended. The fabrication of prototype joints is a useful method of check ing the efficacyofmitigation measures.

Table 6. Minimum spac ing , edge a nd e nd distances for nailsSpacing type Minimum distanceHoles not predrilled Holes predrilled to 80 percent ofnail diameter

End distanceEdge distanceBetween nails Along g rai n Across grain

20 dS d20d O d

lOdS dlOd3d

9.1.4 Na il leng th and t imber th icknessF or the basic loads to apply, th e nails ~Iiouldfully penetrate the tabu la ted s tandard thicknessof members or, for members rece iv ing the nail point, should penetrate to an equivalent depth.Whe re the th ickness of members is less th an those tabu la te d, th e basic lo ad should bereduced proport ionately. No increase in ba sic lo ad is allowed for th ickness of membersgreater than that in Table 2.The nail should be cons ide red as non-load bearing if the penetration of th e head side or pointside is less than 5d.9.1.5 Improved nailsFor sc~uaregrooved or square tw is ted na ils of steel with a yield stress of not less than 375N/mm , the basic lo ads g iven in Table 2 should be mul tip lied by 1.2. The nominal diameter ofth e nail should be assumed to be 0 .7 5 tim es th e d is ta nc e b etw een d ia go na lly o pp os itecorners of the cross-sect ion.9.1.6 Slant drivingThe direction of th e s lan t should be such t ha t the joint will not loosen under load.9.1.7 Avoidance of splittingThe basic loads for nails have been der iv e d on th e assumption that splitt ing of the t imberdoes not occur to any s ign if ican t extent. In wet t imber which shows a marked tendency tosp lit, see C lause 6 ), th e use of predril ied holes of diameter 80 percent of th e nail diameter isrecommended.

10LicencedtoUN


UMP)/D



ib


19/50

M S 544: PART5:2001

9.2 Withdrawal loads9.2.1 Basi c wo rk ing lo adsThe basic working loads in withdrawal for plain shank, low c arbo n s te el n ails a s specif ied inAS 2 3 3 4 driven by hand , in to side grain of timbe r a re g iv en in Table 7.

Table 7. Basi c w ithdrawa l lo ads fo r one nail inserted at righ t ang le s to sid e grainDiameter of nail Basic withdrawal load N/mm of penetration for t imber in group

m m SWG Ji J2 J3 J4 J52. 02 .32 .63 .03 .33 .74. 14.54 .95 .46 .96 .4

1413121 1109876533

5. 86. 77. 68. 79. 610.711.913.114.215.71 7 . 118. 6

4 . 14. 75. 36 . 16 .77. 58 .39.19 .910.911 .913 .0

2 .93 .33 .74 .34 .75 .35 .96 .57 .07 .78 .59 .2

2 .02 .32 .63 .03 .43 .84 .24.65 .05 .56 .06 .5

1. 41. 61. 82 . 12. 32 .62. 83.13 .43 .74 . 14 .4

NOTES:1 . No withdrawal load shou ld be carried by a nail driven into the end grain of t imbers.2 . The penetration ofth e na il should no t be l ess than 15 mm.

9.2.2 Permissible loadsThe permissible load F adm of a single na il in wi thdrawal f rom side g ra in s ha ll be taken to beg iv e n b y

dm = k1 k2 Fw h e r e ;k = 1 . 0 f or all durat ion of loading;k 2 = 1 .0 for both wet and dry tim ber which subsequently will not changeappreciably in moisture content .

= 0.25 where cycl ic changes in mois tu re content can occur a fter na iling ; andF = th e basic working load in wi thdrawal g iven in Table 7.

1 1

LicencedtoUN


UMP)/D



ib


20/50

M S 544: PART 5 2001

9.2.3 Changes in moisture contentThe values of bas ic resistance to wi thdrawal g iven in Table 7 apply to round wire nails driveninto timbe r wh ich subsequently w ill rio t change appreciably in moisture content . Where largechanges in moisture content of t he timbe r subsequen tly to nail ing a re e xp ec te d, th e v a lu esgiven in Table 7 should be mu lt ip lied by 0 . 25 .9.2.4 Improved nailsThe v a lu es of bas ic resistance to wi thd rawa l g iven in Table 7 should be mult ip lied by .5 forr inged-shank or annularly-threaded nails. No reduction in basic resistance to withdrawal ofthese nails need be made where timber sea sons subsequen t to na iling . Howeve r, no load inwi thdrawa l shou ld be carried by r inged-shank or annularly-threaded nails driven into the e ndgrain of the t imber .

10. Screwed joints10.1 Lateral loads10.1.1 Basi c wo rk ing lo adsThe basic working loads for p la in s teel wood s crews as spe cifie d in AS 1476 , whether drivenby hand or by machine, in s ing le shea r in dry t imber are g iv en in Table 8.N OTE . In the absence of specific data, these lo ad s may a ls o be used fo r other forms of steel screws intended for thefabrication of timbe r jo in ts . L oads fo r o th er d iamete rs may be der iv ed by l inear inte rpo la t ion in di rec t propor tion todiameter ra ised tothe power of 1.7.

Table 8. Dry bas ic s ing le shea r lateral loads forone w o od s cre winserted at right angles to side grainDiameter of screw Standard thickness ofmembers m m Basic lat e ra l load N for t imber in group:m m Gauge H e ad -sid e P oint-sid e Ji J2 J3 J4 J52 .7 4 10 19 498 410 340 282 2293.1 5 11 22 587 484 4 0 1 333 2703.4 6 12 24 6 5 5 540 448 3 7 1 3023.8 7 13 27 748 617 5 1 1 424 3444.2 8 15 29 843 695 576 477 3884.5 9 16 32 915 7 5 5 625 518 4 2 14 .9 10 17 34 1012 835 692 574 4665.2 11 18 37 1087 897 742 616 5005 .6 12 20 39 1187 976 8 1 1 672 5466.3 14 22 44 1366 1126 933 774 6287.0 16 25 49 1548 1276 1057 877 7127 .7 18 27 54 1734 1430 1184 982 798

10.1.2 Permissible loadsThe permissible load Fadm for a laterally loaded screw shall be taken to be given by :

Fadm = k 1 k 2 k 1 3 k 1 6 k 1 7 F

1 2LicencedtoUN


UMP)/D



ib


21/50

M S 544: PART5:2001

where;= th e factor for durat ion of load g iv en in Table 4;

k 2 = 1 .0 for dry t imber= 0 .7 for wet timber ;

k 1 3 = 1 .0 for screws in s ide gra in= 0 .7 for screws in e nd g ra in ;k 1 6 = 1 .25 where th e load is appl ied th rough me ta l s ide plates of adequate strengthto transfer th e load and the screws are a c lose f it to th e holes in these plates

= 1 .0 otherwise;= factor formultiple screw joints g iv en in Tables 5.1 and 5 .2 ; and

F = basic working load g iv en in Table 8.

1 0.1 .3 S pa cing s, edge and e nd distancesTable 9 p ro v id es r ecommended minimum spacings, edge and end distances for screwsstated in terms of th e shank diameter d.

Table 9. Minimum spacing, edge a nd e nd d is tances for screwsSpacing type Minimum distance

End distance lOdEdge distance 5dBetween screws- a long g rain-across grain lOd3d

NOTE. d shank d iamete r of screws.For spacing at an angle to th e grain, in terpo lat ion according to Hankinsons formula may beused.10.1.4 Screw length and t imber thicknessFor the basic loads to apply, th e s crews should fully penetrate th e ta bu la te d s ta nd ardthickness of members, or for members receiving the screw point should pene trate to anequivalent depth. Where the th ickness of members are less than those tabulated the basicload should be reduced proport ionately. No increase in basic load is al lowed for th ickness ofmembers greater than those in Table 8. The penetration of the point should be not less than0 .6 of t he s tandard point s ide membe r.

13

LicencedtoUN


UMP)/D



ib


22/50

M S 544: PART 5 2001

10.1.5 Pre-drillingThe v a lu es given in Table 8 apply when the correct size lea d ho le s ha ve been dril led. Thediameter of the hole for th e shank must be equal to the diameter of th e shank, and th e leadhole for the threaded portion of t he sc rew must not be greate r than 7 /8 of th e root d iameter ofth e sc rew ad jacen t to the shank. Sc rews ins ta lled d i rec tl y w i thout pre -dr illi ng have th e sameva lue g iven in Table 8, p rov ided tha t t he t imbe r does not split.10.2 Withdrawal loads10.2.1 Basic wo rk ing lo adsThe b a s i c w o r k i n g l o a d s f o r p l a i n wood screws a s s p e c i f i e d i n AS 1476 d r i v e n b y hand o r b ymachine f r o m t h e s i d e g r a i n o f d r y t i m b e r a r e g i v e n i n T a b l e 1 0 . The maximum w o r k i n g l o a dt h a t may b e a p p l i e d t o a ny on e screw s h a l l n o t exceed t h e v a l u e a p p r o p r i a t e t o t h e d i a m e t e rand meta l from which the s cre w is manufac tu red as given in Table 11. Loads for otherdiameters may be obtained by l inear interpo lat ion in all tables.The basic working loads for wood sc rews dr iven in to end g ra in shall not exceed 70 of thevalues given in Table 1 0 .

Table 10 . Dry bas ic withdrawal loads fo r one wood scr ew insertedat right angles to s id e grainDiameter of screw Basic withdrawal loads N/mm of penetration for t imber in groupm m Gauge Ji J2 J3 J4 J52.7 4 26.5 19.2 14.1 10.3 7 .33. 1 5 30 . 2 21.9 1 6 . 1 11.8 8 .43.4 6 33.0 24.0 17.6 12.9 9. 13.8 7 36.8 26.7 19.6 14.3 10 .24.2 8 40.5 29.4 21.5 15.8 11.24 .5 9 43 . 2 31 .4 2 3 .0 1 6 .9 12.04.9 10 46.9 34.0 25.0 18.3 13.05.2 11 49.7 36.0 26.4 19.4 13.85 .6 12 53.3 38.7 28.4 20.8 14.86 .3 14 59.7 43.3 31.8 23.3 16.57.0 16 66 .1 47.9 35.2 25.8 18.37.7 18 72.4 52.5 38.5 28.2 20.0

Table 11. Maximum permiss ib le wi thdrawal load per screw

MetalMaximum permissible withdrawal load, N

Screw size number I 6 8 10 I 12 I 14 I 18Shank diameter m m2 .7 4 3 .45 4 . 17 4.88 5 .5 9 6 .30 7.72Steel and 18 / 8 s ta in less s tee l 730 1110 1650 2270 2960 3 780 560056 0 850 1270 1750 2280 2 910 4310430 650 970 1340 1740 2230 3300Brass and s ilicon bronzeAluminium alloy

14LicencedtoUN


UMP)/D



ib


23/50

MS544: PART5:2001

10.2.2 Permissible loadsThe permissible load Fadm f o r a s c r e w i n w i t h d r a w a l s h a l l b e t a k e n t o b e g i v e n b y t h e l e s s e r o fth e va lue g iven in Table 1 1 and th e value:

Fadm k 1 k2k1 3Fwhere,k 1 = 1 .0 for all durat ion of loading;k 2 = 1 . O f o r d r y t i m b e r

= 0 . 7 f o r wet t i m b e r ;k1 3

= 1 . 0 f o r screws i n s i d e g r a i n= 0 . 7 f o r screws i n end g r a i n ; and

F = b a s i c w o r k i n g l o a d g i v e n i n T a b l e 1 0 .NOTE. The penetration of t he sc rew po int should no t be le ss than 15 mm .

11. Bolted joints11.1 Genera lThe basic working loads g iv en in 11.2.1 and 11.2.2 are applicable to s tee l bolts as specif ied inAS 1111 , when fitted into pre-dr il led holes of d iameter approx imate ly 10 greater than th ebolt diameter and when f it ted with washers as g iv en in 1 1 .2 .5 .11.2 La te ra l Loads11.2.1 Basic work ing load parallel and perpendicular to grainThe dry basic w o r k i n g l o a d F f o r a s i n g l e b o l t b e a r i n g p r l l l and p e r p e n d i c u l a r t o t h e g r a i nand acting in s in gle shea r is given for a selection of bolt d iameter and e ffec tive t imbe rth ickness in Table 1 2 .

15

LicencedtoUN


UMP)/D



ib


24/50

M S 544: PART 5 2001

Table 12. Dry ba sic loads for one bolt in single shearEffective*timberthickness bm m

Boltdiameterm m

Basic load k N fo r t imber in group~ J2 J3 J4

_____J5

Pa r Perp Pa r Perp Pa r Perp Pa r Perp Par Perp12.7 6 .39.512.715.919.0

22.2

0 . 801.211.581.922.222.46

0.530.650.760.850.951.04

0.630.961.261.521.761.97

0 . 370.450 . 530.600.670.73

0.500.760.981.191.381.55

0.280.330.380.440.490.54

0.410.600.790.961.101.24

0.200.240.280 .310.360.38

0.290.420.550.660.760.85

0.130.150.180.200.230.2519.0 6 .39.512.715.919.022.225.4

1.121.742.332.823.303 .714.10

0.790.971.131.271.421.561.69

0.901.391.862.242.632.953.25

0 . 560.680.800.901 .011.101.20

0.711.091.461.762.062.302.54

0 . 4 10.500.590.660.730.800.88

0.580.891.181.421.661.852.04

0.300.360.420.480.530.590.64

0.410 .610.800.971.141.271.40

0.190.240.280 .310.350.370 .4125 . 4 6 .39.512.715.919.0

22.225 . 4

1.302.223 .013 . 724.364 .915 . 46

1.021.301 .511.701 .902.082.26

1 .091.792 .412.963.483 .914 . 34

0 . 740.921.071.201.341.481.60

0 .881.421 .912 . 342.723.063.40

0 .540.670.780.880.981.081.16

0 .721.131.541.872.182.462 . 72

0.400.480.560.640 .710.780.84

0 . 520.801.071.301 .511.691.88

0 .240 .310.360.410.460.500.5438.1 6 .39.512.715 .919.0

22.225.4

1.302.844.225.286.297.168.32

1.341.872.242.542.843.123.40

1.142.383 .414.255.045.726.62

1.031.371.601.802.022 .212.40

0.951.922.703.363.964 .515 .21

0.761.001.161.321.461.621.75

0.761.582.202 .713.203.634.19

0 . 560.720.840.951.071.161.27

0 . 551.121.541.882.222.502.89

0.360.470.540 .610.680.760.8250.8 6 .39.512.715.919.022.225.4

1.302.844.946.658.009.1810.37

1.342.342.923.373.794.164.52

1.142.504.105.386.447.378.30

1.101.762 .112.402.692.953.20

0.952.083.064.285.105.836.55

0.861.281 .551 .751 .962.152.34

0.761.762.743.484.144.72528

0 . 660.951.131.271.421.561.69

0.551.271.932.442.883.283.66

0.440.600.720.820 .911.101 .0976.2 9.512.715.919.0

22.225.428.6

2.844.947.4310.3012.5814 .5215 . 9 4

2.563.844.75506.186.747.33

2.504.336.538.5710.2211.7112.85

1 .812.983.503.984.404 . 805.20

2.083.605 .416 .918.179.3110 . 1 6

1.582.172.562.923.233.503.79

1.763.064 .615 .716.677.568.23

1.221 .611.902 .112.342.532.74

1.272.223.174.044.685 . 275.75

0.821 .031 .201.371.511.631.76

101.6 12.715.919.022.225.428.631.7

4.947.4310.3013 . 4 316 . 9 919.6221.74

3.985.626.857.868.749 .6110 .41

4.336.539.0211 . 8 014 .1115.9617.59

3.164.375.155.776.346.897.46

3.605 .417.499.7911 . 4 012 . 8 014.02

2.473.203.764.224.635.055.45

3.064 .616.388.149.4210.4811.44

1.902.382.763.083.373.663.94

2.223.174.395.766.667.367.99

1 .261 .551 .761 .982.172.362.54127 .0 15.919.0

22.225.428.631 . 7

7 . 4310.3013 . 4 316.9920.5324.31

5 .627.499.1210 . 4 211 . 5 312.72

6 .539.0211 . 8 014 . 9 218 . 0 220 .22

4 . 455.946.927.738.489.23

5.417.499.7912 . 3 814 . 7 216.33

3 .484.395.085.656.206.74

4.616.388.3410 . 5 512.2013 .50

2.683.283.734.154.524.90

3 . 174.396.027.628.659.55

1.782.142.402.662.923.17

1 6LicencedtoUN


UMP)/D



ib


25/50

MS544: PART5:2001

Table 12. Dry basic loads for one bolt in s ing le shea r cont inuedEffectivet imberthickness*

m m

Boltdiameterm m

Basic load k N for timber in groupJi J2

Pa r Perp Pa r Perp Pa r Perp Par Perp Par Perp152 .4 19.022.225 . 428.631 . 7

10.3013.4316 .9920.5324.31

7 . 499 .6111 .9413 . 2 614 .74

9.0211 . 8 014.9218 . 0 221 .34

5.947.638.939 .9110.85

7 .499.7912 .3814.9817 .72

4 . 645.726.527.267.94

6 .388.3410.5512.7415.08

3 .564.274.825.345.83

4 . 396.027 . 629.2010 .75

2.362.783.113.423.73203 .2 22 . 225.428.631.7

13.4316 . 9 920.5324 . 3 1

9.6111.9414.5217.36

11.8014 . 9 218 . 0 221.34

7.639.4811 . 5 313 . 5 6

9.7912.3814.9817.72

5.957.408.829.92

8.3410 . 5 512.7415 . 0 8

4.575.696.627.36

6.027.629.2010.90

3.053.787.324.79

the loads for intermediate thickness may be obtained by linear interpolation.The units for timber thickness and boltdiameter are directconversion from imperial units.

11.2 .2 Ba sic working load fo r a bolted joint systema Parallel and perpendicular to grain

For a bolt in other than a two member j o i n t t h e b a s i c w o r k i n g l o a d s h a l l b e m u l t i p l e sof F for pa ra lle l lo ad ing as shown in Table 13 and F1 for pe rpend ic ula r lo ad ing asshown in Table 14 for the appropr ia te type of joint.b) Othe r ang les to grain

For systems loaded at an angle a to th e grain, the basic working load is given by useof Hank inson s fo rmula as follows:-

FFIIFsin2ci F cos2a 1

Hankinsons formula is conveniently e va lu ate d b y means of th e nomogram g iv en in Figure 3.

1 7

LicencedtoUN


UMP)/D



ib


26/50

M S 544: PART 5 2001

Table 13. Basic wo rk ing lo ads for a bolted joint system loaded parallel to gra inType of joint Effective t imberth ickness b Basic load F

1 . Tw o memberI I 1I~I~1

Smaller of 2 b 1 and 2b2 F

2 . Three member

I I I

Smaller of 2 b 1 and b 2 F

3 . Mul tip le member

A b1B b2 C j b3

ID / b4

i Between A and B Smaller of b 1 and b2ii) Between B and C Smaller of b and b3iii) etc.

i F ii) F iii) etc.Totalbasic load sum of basicloads i) , ii), etc.

1 8LicencedtoUN


UMP)/D



ib


27/50

M S 544: PART5 :2001

Table 14 . Basic working loads for a bolted joint system loaded perpendicular to grainType of jo int Effective timber thickness b Basic load F ~

1 . Tw o memberb

ft~

2 b, but n ot exceeding twicethickness of s ide member. F ~

2. Three memberb b 1~ i b bu t no t exceeding twicethickness of thinner sidemember .ii) 2 b butnot exceedingth ickness of innermember. i 2 F 1ii) 2 F1

4 . Multiple member

~~

Between A and B thinner of b and bii) Between B and C thinner of b2an d b3iii Between C an d Dthinner of b3an d b4iv ) etc.

F 1ii) F 1ii F

1

Total basic load sum ofbasicv) etc.loads i), ii), iii) etc.

1 9

LicencedtoUN


UMP)/D



ib


28/50

M S 544: PART5 :2001

F;

Figure 3. G ra ph o f H a nk in so n formulaEXAMPLEGiven F = 9 .0 kN F1 6. 0 kN, c x 60To find F c c connect F = 9 .0 to F 1 6.0.At in te rsect ion w ith 60 line, construct l ine para llel to grid line to axis at F c c = 6.5.

11.2.3 Permissible loadsThe permissible load F adm of a laterally loaded bolt system shall be taken to be given by:

20

Fi

LicencedtoUN


UMP)/D



ib


29/50

M S 544: PART 5 2001

1 1 .2 .3 P e rm is sible lo a dsThe permissible load F adm of a laterally loaded bolt system shall be taken to be given by:F adm = k 1 k 2 k 1 6 k 1 7 Fwhere,k 1 = the fac tor for durat ion of load given in Table 4;

= 1.Ofordrytimber= 0 .7 for wet t imber;

k 1 6 = .2 5 for bolts that tra n sfe r lo ad th ro ugh me ta l s ide p la te s of adequatestrength and the bolts are a close fit to th e holes in these plates provided thatb /d > 5 for loads acting paralle l to grain and b /d > 10 for lo ad s a ctin gperpendicular to th e grain where b denotes th e e ffe ctiv e timber th ic knessand d is the bo lt diameter)= 1 .0 otherwise;

k 1 7 = factor formultiple bolted joint giv en in Table 15; andF = bas ic work ing load as derived in 11 .2 . 2 .

Table 1 5 . Va lues of factor k 1 7 fo r use in th e design of multi ple connector joints ofbolts, coach screws, split ring and shear plates~[ Value of k oint

fla4 fla 5 fib =10 tjo =15 7 o 161.00restraint*) 1.00restraint 0.50

0.950 .950.500.800 .800.50

0.650 .550.500 . 620 . 500.50

of fasteners in each row per interface.restraint refers to the possibilityof restraint to timber shrinkage due to the joint detail.

2 1

LicencedtoUN


UMP)/D



ib


30/50

M S 544: PART 5 2001

1 1.2 .4 S p ac in gs , edge and end distancesSpac ings, e dge a nd end d is tances sha ll comply with the following requirements:a) Loads parallel to grain

The bas ic wo rking lo ads g iven in Tables 12 and 13 apply to joints in which t he edge ,end and between- fastener spacings are not less th an th os e s hown in Figure 4a. Thedistance a indicated in t he figu re shall be at least n 2 d with a minimum of 2.5d,where n is th e total number of bolts in the joint and d is t he d iame te r of th e bolt.Simila r ly , the requ ired end distance parshall be at least 7d in tension joints in both wetand dry t imber and 4d in compression joints and in joints sub je cted to bendingmoment for both mo is tu re cond itions. Howeve r, le sser end distances may be used intension joint p ro v id ed th at th e bas ic lo ad is reduced in proport ion to the reduction inend distance.Nevertheless, in no case sha ll th e end distance for tension joints be less than 6d forwet t imber and 4dfor dry t imber .

b) Loads perpendicula r to grainThe minimum edge, end and between-fastener spacing sha ll not be less than thoseshown in Figure 4b. The distance a shal l be at least 2 . 5d for a bid ratio of 2, and itshall be increased proport ionately so that it is at least 5d for a bid ratio of 6 or more,where b is the thickness of th e membe r loaded perpendicular to the grain.

c) Loads ac ti ng at an angle to th e grainFor loads acting at an angle 00 to 30 to the grain, the spacings, edge and enddistances may be taken as for loads para llel to th e grain. For lo ad s acting at an angleof 3 0 to 9 0 to th e grain, the spacings, edge and end distances may be taken as forloads act ing perpendicular to th e grain.

2 2LicencedtoUN


UMP)/D



ib


31/50

M S 544: PART 5 2001

4

b) Load applied pe rpendicula r to g ra inFigure 4 . Spacing, edge a nd e nd distances for bolted joints

a) Load applied paral le l to grain

pa r

23

LicencedtoUN


UMP)/D



ib


32/50

M S 544 : PART 5 : 2001

11.2.5 WashersIn al l t imber-to-t imber bolted structural joints, every bolt shall be provided with a washer ateac h end , of a size not less than t ha t s ta ted in Table 16. If smaller washers are used , then th ebasic working lo ad g iven in 1 1 .2 s ha ll be re du ce d in proport ion to th e dimension of th e w a sh erd iameter or s ide length .

Table 16. Minimum required s iz e o f washers for structural bolted jointsWasher size m mdiameter

.Thickness .Mm. diameter fo r roundwashers.Mm. s ide length for squarewashers

1 .6 30 252 .0 36 3 22 .5 45 403.0 55 504 .0 65 5 75 .0 75 656. 0 85 75

11.3 Axial loadsWhere b o l t s a r e l o a d e d a x i a l l y t h e b a s i c w o r k i n g l o a d o f t h e b o l t s ha l l b e t a k e n a s t he l es s e ro f t h e a x i a l s t r e n g t h o f t h e b o l t and t h e b e a ri n g s t r e n g t h o f t h e t i m b e r u n d e r t h e washer whenloaded perpendicular to th e grain. The des ig n a xia l s tre ng th of bolts and th e e ffe ctiv ediameter for us e in comput ing th e bearing pressure on th e timber a re g iv en in Table 17.

Table 17. Design parameters fo r bolts under axial loadBolt diameterm m Axial strength of bol tk N Effective diameter of a standard washer* in bearingm m

M6 4.0 16M8 7.5 21M10 11 .5 27M12 17 3 1M16 3250 3 1M20 50M24 72 60M30 115 69M36 1 6 5 78

Standard washers are washers having the minimum dimensions shown in Table 16 . The ef fec t ive d iameter is lessthan the actual diameter because it includes an allowance for bending ofthe washer.

24LicencedtoUN


UMP)/D



ib


33/50

MS544: PART5 :2001

12 Coach screws12.1 Genera lThe basic working loads g iv en in the follow ing clauses are appl icable to steel coach screwsas spec if ied in AS 1 3 9 3 and a s s hown in Figure 5.12.2 La te ra l loadsFor coa ch screw s be arin g laterally in dry t imber, th e provision of Clause 1 1 for bolts s ha llapply, subject to the following condit ions:a) for the purpose of Clause 11, a coach screw shall be considered to be a bolt ofdiameter equal to th e shank d iame te r of the screw;b) th e screws sha ll be fitted with washers as spec if ied in 1 1 .2 .5 ;c ) in a two-member joint, th e th in ne r membe r sha ll h ave a minimum th ickness of three

t imes th e shank d iame te r of th e coach screw ;d) The diameter of th e hole for the shank shall not be less than th e s ha nk d iamete r ofthe screw nor exceed it by more than mm or 10 percent of th e s ha nk diameter,whichever is the lesser. The d iameter of th e hole for the threaded portion of th e s crewshall n ot e xc ee d th e ro ot d iame te r of the screw. The depth of the hole sha ll not beless than the intended dep th to w hich th e s cr ew is to be driven. The screw shal l notbe h ammere d in to place bu t turned with a hand ope ra te d or mach in e ope ra tedwrench; ande) Timber thickness and screw lengths as shown in the Figure 6 shall be such that:

i th ickness of first member, t > 3dii) depth of penetration into second member , for spec ies in joint groups:JlandJ2 t ~ > dJ 3 t~ >8dJ4andJ5 t~>lOdFor t he lesse r values of t~he basic load sha ll be reduced in proport ion to th edecrease in t~nd th e coach screw shall be cons ide red as non-load bearing ift~s less than 4d.

25

LicencedtoUN


UMP)/D



ib


34/50

IDea d ~~:~;i~D = S ha nk o r nominal diameterS = Length of shank or unthreaded portionT= Length of threaded portion

Figure 5 . Coach screw

M S 544: PART5:2001

Figure 6. Timber thicknesses and fastener lengths fo r c oa ch screws

26

LicencedtoUN


UMP)/D



ib


35/50

M S 544: PART 5 : 2001

12.3 Withdrawal loads12.3.1 Basi c wo rk ing lo adsThe basic working loads for coach screw in withdrawal from the side grain are given in Table18.12.3.2 Permissible loadsThe pe rm is sib le w ith dr awa l load Fadm for a coach screw in withdrawal shall be taken to begiven by :Fadm = k 1 k2k13Fb u t n o t g re a t er t h a n t h e v a l u e g i v e n i n T a b l e 1 9where;k 1 = 1 .0 fo r coach screw for all durat ion of load ing ;k 2 = 1.Ofordrytimber

= 0 .7 for wet t imber;k 1 3 = 1.0 for coach screws in side grain

= 0 .7 fo r coach screws in end g ra in ; a ndF = basic wo rk ing load for c oach s crews in side grain, given in Table 18.

Table 18. D ry ba sic withdrawal loads fo r coach screws in side grainShankdiameterm m

Basic withdrawal load, N pe r mm penetration of tread for t imber in groupJ 1 J2 J3 J4 J56 57 41 30 22 168 75 54 40 29 2 110 93 68 50 36 2612 1 1 1 80 59 43 3 116 146 10 6 78 57 4020 181 131 96 71 50

Table 19. Max imum permiss ib le w i thdrawa l lo ads per coach screwsNominal diameter o f coach screw m m Maximum permiss ib le wi thdrawal load N

6810121620

20004000600090002000031500

27

LicencedtoUN


UMP)/D



ib


36/50

M S 544: PART5 : 2001

13 Split ring connectors13.1 General13.1.1 Connector sizesThe recommendations c o n t a i n e d i n t h i s c l a u s e a re a p p l i c a b l e t o t h e s i z e s o f s p l i t r i n gconnectors given in Table 2 0 and conforming to BS 1579 .

Table 20. Sizes of split-ring connectors and minimum sizes of washersNominal s iz e o fconnectors

m m

Nominal s iz e a nd threaddiameter of bol t Minimum size of round or square washersDiameter or length of I Thicknesssidemm mm50 375

64 M12102 M20

NOTE. The sizes given in this table are metricconversions of the imperial sizes given in BS 1 5 7 9 .

13.1.2 Bolts and washersThe diameter of the bolts to be used with th e c o n n e c t o r s a r e g i v e n i n T a b l e 2 0 .Round or square washers should be fitted between th e timber and the head and nut of th ebolt. The m in imum size of washer to be used with each connector is given in Table 2 0 .13.1.3 Joint preparat ionTo prepare a connectored joint, th e positions of th e b olt holes should be s et o ut a cc ura te lywith reference to the point of intersection of the cen tre-lines of the memb ers . One of th efollowing two p rocedu res should be used when dr il ling the bo lt holes:a) fit th e membe rs to ge th er in their correct posit ions and c lamp while dril l ing th e boltho les through all the members; andb) drill th e bolt holes in th e individual members using jig s o r templates to lo ca te th e boltholes accurate ly .Bolt holes should be within 2 mm ol their spec if ied positi on . T he c on ta ct surfaces of th et imber members should be g ro oved to the d imens ions given in Table 2 1 .The grooves for split-rings may be cu t s imu ltaneous ly with t he d r illing of the bo lt holes ifprocedure b) is used.

28

LicencedtoUN


UMP)/D



ib


37/50

M S 544: PART 5 : 2001

Table 21. Dimensions of circular grooves for split-ring connectorsSplit-ring sizem m Dimensions of groovem m

64

102

65.0 4.6 9 .5

13.2 Effect ive cross sectionThe effective cross-section of each member at a joint should be d e t e r m i n e d b y d e d u c t i n g t h ep ro je cted a rea from th e gross area of the cross-sect ion of th e connector recess .e . 7 0 5 mm2for each 6 4 mm split-ring, or 1 45 5 mm2 for each 102 mm split-ring) and the projec ted area ofth e groove. The d epths o f th e connector grooves are g iv en in Table 2 1 .When assessing the e ffec tive cross-sect ion of mult ip le connector joints, a ll c onnector s andtheir bolts that lie within a distance of 0.75 connector diameters, measured pa ra lle l to thegrain from a g iven c ross -sec tion should be cons ide red as o cc urr in g at tha t c ross-sec tion.Then the effective c ro ss sec tio n should be dete rm ined b y deduc ting the given net projectedareas of the connector grooves and bolt holes from the g ro ss a re a of the c ross -sec tion be ingconsidered.13.3 Basic lo adsThe basic working loads for parallel and perpendicular to the joint in dry t imber are g iv en inTable 2 2 . These loads apply to a connector unit comprising one split-ring in the contact facesof a t imber-to-t imber jo int wi th its bolt in single shear. When lo ad ed a t an angle a to the grain,th e basic load is given by use of Hankinsons formula or e valu ate d b y means of th e graph asgiven in Figure 3 .

29

LicencedtoUN


UMP)/D



ib


38/50

Cl U 0 0

Te2Dybclo

foos

nc

ou

0

Authc

o

membs

Bcloa~kNombngo

S

n

damee

mm

Bdamee

mm

C

os

oosd

oy

~mm

C

oso

bhsda

osmeb

mm

J

J

J

J

J

P

Pp

P

Pp

P

Pp

P

Pp

P

Pp

6

M1

2 2 2

3 4 5

13

16

14

67 82 10

78

95

16

51 63 77

59 72 88

39 48 59

45 55 67

30 37 45

33

41 50

22 28 34

1

M2

2 3 3 4

4 5 6 7

23

26

33

33

15

12

10

22

15

29

26

22

16

16

19

18

15

11

19

21

83 10

17

15

14

14

16

15

66 79 92 98

78 93 19

16

5 6 71 76

1L

foinemeaethc

maboanbln

nepao

LicencedtoUNIVERSITIMALAYSIAPAHANG

(UMP)/Downloadedon:01-Jul-2009/Singleuserlicence

only,copyingandnetworkingprohib


39/50

MS544: PART5:2001

13.4 Permissible loadsThe permissible load Fadm for split-ring connector shall be taken to be given by :Fadm k 1 1 2 k 1 7 k 1 8 Fw h e r e ;k 1 = factor for duration of load given in Table 4;k 2 = 1.Ofordrytimber

= 0 .7 fo r wet t imber;k

1 7factor formul tip le connector joints given in Table 15 ;

k 1 8 = 1 .0 for standard an d end d is tance , edge distance and connector spacing asgiven in Tables 2 3 , 2 4 and 25 respectively= modif icat ion factor for th e r ele vant connector spac ing ks), end distance kc) andedge distance k 0 ) w hich are less than th e cor re spond in g s ta ndard values asgiven in Tables 2 5 , 26 and 27 respec ti vely . he lowes t factor of th e va lues of k5 kc and k D is to be u sed see 1 3.5 ); and

F = basic load g iv en in Table 2 2 .13.5 Spacing, edge a nd e nd distancesAssociated with each size of spl it -r ing connector is standard end d is tance , edge distance andspacing between connec tors which permit the basic load to apply. These s tanda rd distance sare given in Table 2 3 to Table 2 5 . If the end d is tance , edge distance or spacing is less thant he s tandard, bu t more than th e minimum, the basic load should be modif ied as g iv en in 1 3 .4 .No increase in load is permitted if end distance, edge distance or centre spacing exceed thes ta nd ard v a lu es . T he defin itio n o f end d is tance , edge distance and spacing is illustrated inFigure 7 .I f split-ring connec to rs a re used in wet t imbe r , the standard end d is tance shou ld be multipliedby . 5 . One-hal f of this increased end distance should be taken as th e minimum end distance,with a permiss ib le load of one-half of that permitted for the standard end distance.

3 1

LicencedtoUN


UMP)/D



ib


40/50

M S 544: PART 5 : 2001

Table 23 . End distances for split-ring and shear -p la te connectorsType o f e nddistance Angle 1 of loadto g ra in c c End

1~ distancem mConnector size

64 mm spli t- ring or 67mm 102mm spli t-r ing or 102mm

degreesshear-pla te shear-pla te

M inimum Standard M inimum StandardUnloaded 0 64 102 83 140

45 67 1 2 1 86 15990 70 140 89 178

Loaded Oto9O 70 140 89 178Fo r i n termedia te angles a nd e nd distances, values should be obtained by l inear interpolation.

Table 24 . Edge distances for split-ring and shear -p la te connectorsType of edge Angle 1 of load Edge d is tancedistance to grain c x m m

Connector size6 4mm split-ring or67 mm 1 0 2mm split-ring or 1 0 2mm

Degreesshear-plate shear-plate

M inimum Standard Minimum StandardUnloaded Oto9O 44 44 70 70Loaded 0 44 44 70 70

45 44 54 70 7990 44 64 70 87

45to90 44 70 70 95 For in termedia te angles and end distances, va lues should be obtained by l inear interpolation.

3 2LicencedtoUN


UMP)/D



ib


41/50


42/50

M S 544: PART 5 : 2001

Table 25 . Spacing modification factor, k5 fo r split-ring and shear-plate connectors

continuedAng le of Angle of Spacingload to connector m mgrain c c axisto grain k~=0 75 k~=0 80 i ~=0 85 k~ 0.90 k~=0 95 k5 =1.00degrees 0 M inimum Standarddegrees

102 m m split-ring or 102mm shear-plate

153045607590

1 2 71 2 7127127127127127

1461 4 31 4 01 3 31 3 01 2 71 2 7

1 6 81 6 2149140133127127

1 871 7 81621 4 61 3 31 3 0127

2 101 9 71711 4 91 4 21 3 01 2 7

2 2 92131 8 31571 4 01 3 01 2 7

1 5 15305607590

1 2 71271271 2 7127127127

1 4 31 4 01 3 7~31 3 01 3 01 3 0

1591521461 4 0133133130

1711 6 81 5 914 91 4 01 3 31 3 3

1 8 71811 6 81 561 4 21 3 71 3 7

2031 9 51 7 816 11 4 71 4 01 3 7

30 0153045607590

127127127127127127127

1 3 71 3 71 3 31 3 31 3 31 3 01 3 0

1461 4 61 4 31401371 3 71 3 7

1 5 91 5 614 91 4 61 4 31 4 01 4 0

1 6 81 6 51 591 5 21 4 61 4 51 4 3

1 7 81 7 51 681 6 01 5 21 4 81 4 6

45 15305607590

1 2 71271271 2 71271 2 7127

1331 3 31 3 31331 3 31331 3 3

1 371371371 371401 4 0140

1 4 31 4 31 4 31 4 31 4 61461 4 6

1 4 614 614 61 4 61 4 914 91 4 9

1 5 21521 531541 5 51561 5 6

6 0 to 90

~

153045607590

1 2 71271 2 71271 2 71271 27

12 712 71 2 71 3 013313 3133

1 2 71271 301 3 31 371401 4 3

4 2 71271301 3 31 4 314 6149

12 712 71331 3 714 615 215 9

12712 91 341 4 21521 6 1165

34LicencedtoUN


UMP)/D



ib


43/50

MS 544: PART5:2001

Table 26 . End distances modification factor, k fo r split-ring and shear-plateconnectorsVa lue o f_k0nloaded Loaded

Connector size .Connector size64 mm split-ring or 67 mm 10 2 mm spli t- ring or 102 m mshear-plate shear-plate

64 mm split-ring or 67mm shear-plate

102 m msplit-ring or102 m mshear-plateAngle 1> of load to grain a

4 5 90 45 90 t o 90 to 90

0.630.680.730.780.830.880.930.981.001.001.001.001.001.001.001.001.001.001.001.001 .001 .001.001.00

0.640.680 . 7 10.750.780.820.850.890.920.960.991.001.001.001.001.001.001.001.001 .001 .001.001.00

0.620.650.670.700.730.760.780 . 8 10.840.860.890.920.950.971 . 0 01.001 . 0 01 . 0 01.001.001.001 . 0 01.00

0.630.670.700.730.770.800.830.870.900.930.971 . 0 01.001.001 . 0 01.001 .001 .001.001.00

-

0.640.670.690.720.740.770.800.820.850.880.900.930.950.981.001.001.001.001.00

0.620.650.670.690 . 7 10.730.750.770.800.820.840.860.880.900.920 . 940 . 970.991.00

.

0.620.650.670.700.730.760.780 . 8 10.840.860.890.920.950.971 . 0 01 . 0 01 . 0 01 . 0 01.001 .001 .001.001.00

0.620.650.670.690 . 7 10.730.750.770.800.820.840.860.880.900 . 920 . 940.970.991.00

intermediate anglesand end distances, values should be obtained by linear interpolation.

35

LicencedtoUN


UMP)/D



ib


44/50

M S 544: PART 5 2001

Table 27. Loaded, edge distances modi fica tion factor, k~,or split-ring and shear-plateconnectorsEdgeDistancem m

V a lu e o f ~

Connector size64 mm spli t- ring or 67 mm shear-plate 102 mm split-ring or 102mm shear-plate

Angle ~ of load to grain a

-

15 30 4 5 15 30 4 5 t o 904 55055

1.001.001.00

0.940.981.00

0.890.930.96

0.830.870.90

-

6 06 57 0

1.001.001.00

1.001.001.00

0.991 . 0 01.00

0.930.971.00

.

1.00

0.94

0.89

-

-0.83

7 58085

1.001.001.00

1.001.001 . 0 0

1 . 0 01 . 0 01 . 0 0

1 . 0 01 . 0 01 . 0 0

1.001 . 0 01.00

0.981.001.00

0.920.950.99

0.860.900.93

9095

1.001.00

1 . 0 01.00

1 . 0 01 .00

1 . 0 01 .00

1 . 0 01 .00

1.001.00

1 . 0 01.00

0.971 .00

For intermediate angles and en d distances, values should be obtained by linear interpolation.

Figure 7. Spacing, Edge and End distances fo r split-ring and shear -p la te connectors

a 4

a a 3

Legend:a = Spacing p a ra l le l t o g ra i n;a2 = Spacing perpendicular t o grain;a3 = end d i s t a n c e ; anda 4 = edge distance.

36LicencedtoUN


UMP)/D



ib


45/50

MS544: PART5 :2001

14 . Shear plate connectors1 4 . 1 General14 li Connector sizesThe recommendat ions contained in th is clause a r e a p p l i c a b l e t o t h e s i z e s o f s h e a r p l a t econnectors given in Table 28 and conforming to BS 1 57 9.The following requirements rela te to shear plate connectors of nom in al 6 7 mm and 102 mmsizes.

Table 28. Sizes of shear-plate connectors and minimum sizes of washersNominal size ofconnector

m m

Nominal s iz e a nd threaddiameter o f bo lt Minimum s iz e o f round or square washersDiameter or length ofsidem m

Thicknessm m

67 M20 75 5102 M20 75 5

NOTE. The s izes g iven in this table are metr ic convers ions of the imper ia l sizes given in BS 1 5 7 9 .

14.1.2 Bolts and washersThe diameter of the bolts to be used with th e connectors are g iv en in Table 20.Round or square washers should be fitted between th e timber and th e head and nut of th ebolt. The m in imum size of washer to be used with each connector is given in Table 2 0 .14.1.3 Joint preparationTo prepare a connectored joint, the pos it ions of the b olt holes should be se t out accuratelywith reference to th e point of intersection of the cent re -lines of th e membe rs . One of thefollowing two p rocedu res should be u sed when dr i ll ing the bolt holes:a) fit th e membe rs to ge th er in their correct positions and clamp while d rillin g th e b oltho les through all th e members; andb) d rill th e bolt holes in the ind iv idual members using j igs or templates to locate the boltholes accurately.Bolt holes should be within 2 mm of their specified position.The contact surfaces be within 2 mm of the t imber members should be recessed to thedimensions shown in Figure 8.The recesses for shear-plates may be cu t s imu l taneous ly with the dr ill ing of th e bolt holes ifprocedure b) is used.

37

LicencedtoUN


UMP)/D



ib


46/50

M S 544: PART5 : 2001

11.5

1 6 . 5 6 . 0

67

L 57 J

Figure 8. a Recess for 67 mm connector unit0 1 0 2 . 5

89

Figure 8 . b Recess fo r 102 mm connector unitAlld imens ions a re in mill imetres.

Figure 8. Dimension of circular recesses for shear -p la te connector units conforming toBS 1579

039.5

1 3

22~4 ~

3 8

LicencedtoUN


UMP)/D



ib


47/50

M S 544: PART 5 : 2001

14.2 Effect ive cross sectionThe effect ive cross-sect ion of each member at a joint should be de te rm ined by deduc ting thep ro je cted a rea from th e g ross a rea of th e cross-section of th e connector recess i.e. 7 7 0 mm2for each 67 mm shear-plate, or 1690 mm2 for each 1 02 mm shear-plate) and th e projectedarea of th e bolt hole not within the projec ted area of the recess. The de pths o f the connec to rrecess are 11 .5 mm and 16 .5 mm for th e 67 mm and 10 2 mm shear-plates, respective ly .When a ss es sin g th e e ffe ctiv e cross-sect ion of multiple connec tor joints, al l connectors andtheir bolts that lie within a distance of 0 .7 5 c onnec to r d iamete rs , measure d para lle l to th eg ra in from a given cross-section should be c onsider ed as o cc ur rin g at tha t c ross-sect ion .Then th e effective cross section should be de te rm ined by deducting the given net p ro jec tedareas of th e connector recesses and bolt holes from th e g ross a rea of the c ross -sec tion be ingconsidered.14.3 Basic lo adsThe basic working loads for parallel and perpendicular to th e grain in dry timber are g iv en inTable 2 9 . These bas ic lo ads apply to a connector unit either:a) one shear plate with its bolt in single shear in a steel plate-to t imber joint; orb) tw o shear plate back to back with the bolt in single shear, in a t imber-to t imber joint.When loaded at an angle a to th e grain, th e basic load is g iv en by use of Hankinsons formulaor evaluated by means o f the graph as g iv en in Figure 3.

39

LicencedtoUN


UMP)/D



ib


48/50

I 1 -o

Te2Dybclo

foos

paec

ou

0

Auhc

omembs

Bcloa~kNombngo

S pae

damee

mm

Bdamee

mm

C

os

oosd

oy

mm

C

os

obh

sda

osme

b mm

J

J

~

J

P

Pp

~

Pp

P

Pp

P

Pp

P

Pp

6

M2

4

4 5 6

19

15

14~

77 94 10

89 19

16

59 72 77

68 83 88

45

55

59

52 63

67

35

43

45

38 47 50

26 32 3

4

1

M2

4 4

5 6 7 9

24

20

27~

26

14

16

16

18

13

11

25

20

97 14

12

11

10

12

13

15

76

90

96

13

13

11

10

10

60

71

76

82

80 94 11

18

46

54

58 63

odsforintermediatethicknessbeoanbln

nepao

seecluse44

LicencedtoUNIVERSITIMALAYSIAPAHANG

(UMP)/Downloadedon:01-Jul-2009/Singleuserlicence

only,copyingandnetworkingprohib


49/50


50/50

SITIMALAYSIAPAHANG(

UMP)/D



ib

Date post:	03-Jun-2018
Category:	Documents
Upload:	esahjamil
View:	238 times
Download:	0 times

MS 544 PART 5 2001 Timber Joints

Documents