Comparative Study of Glass Design Standards PM - Mathieu Meur.pdf · Comparative Study of Glass...

Comparative Study

of Glass Design

StandardsMathieu Meur

November 2017

Comparative Study of Glass Design Standards

▪ Review of glass behaviour

▪ Design standards for glass sheets

▪ Design of glass fins

▪ Design of bolted glass

▪ Beyond standards







Glass Behaviour

▪ Brittle material

(theory v/s actual)

© University ofTexas Arlington

© E. Premalatha, Dr. C. Umarani

Glass Behaviour

© Gang Deng and Tsutomu Nakanishi

▪ Breakage initiated from micro-cracks

Glass Behaviour

▪ Large deflections –

non-linear

behaviour

© E. Premalatha, Dr. C. Umarani

Glass Behaviour

▪ Behaviour changes

with duration of

loading (creep)

Glass Behaviour

▪ Laminated glass behaviour changes with temperature

Shearmodulus,G(MPa)

20˚C 8.06 1.64 0.840 0.508 0.372 0.266

30˚C 0.971 0.753 0.441 0.281 0.069 0.052

40˚C 0.610 0.455 0.234 0.234 0.052 0.052

50˚C 0.440 0.290 0.052 0.052 0.052 0.052

Poissonratio,v

20˚C 0.4980 0.4996 0.4998 0.4999 0.4999 0.4999

30˚C 0.4998 0.4998 0.4999 0.4999 0.5000 0.5000

40˚C 0.4998 0.4999 0.4999 0.4999 0.5000 0.5000

50˚C 0.4999 0.4999 0.4999 0.4999 0.5000 0.5000

1mo. >1yr.GPVB(MPa)

nPVB 3s 1min. 1hr. 1day 1mo. >1yr.

3s 1min. 1hr. 1day

Glass Behaviour

▪ Laminated glass behaviour changes with temperature







Glass Design Standards

Standards covered:

▪ ASTM E1300 – US standard

▪ AS 1288 – Australia standard

▪ BS 6262/ 5516 – Bristish standard

▪ TRLV – German technical regulation

▪ prEN 16612/16613 – proposed European standard (not approved)

▪ JGJ 102 – Chinese standard


Other standards not covered:

▪ IS 16231 – India standard – Inspired from AS 1288 and BS 6262

▪ NF DTU 39 – French norm

▪ CAN/CGSB 12 – Canadian standard

▪ NBN S 23-002 – Belgium standard


▪ Focus on structural design aspects

▪ Impact safety not covered

▪ Thermal and visual performance not covered

▪ Aesthetics not covered


▪ Definitions of AN, HS and FT

▪ Deflection limits at centre / edges

▪ Stress limits

▪ Load distribution (laminated / IGU)

▪ Mixed thickness glass consideration

▪ Point-fixed glass consideration


▪ Design of curved glass

▪ Design breakage rate

Glass Design Standards – Definitions

ANNEALED GLASS HEAT-STRENGTHENED FULLY TEMPEREDASTM E1300

Residual surface stress near 0Surface compression of 24-52MPa Surface compression >69MPa

AS 1288 ---Surface compressionof 24-69MPa

Surface compression>69MPa

BS 6262/ 5516 --- --- ---TRLV --- --- ---

prEN 16612/16613

Glass which has been treated during manufacture to minimise the residual stress in the glass, allowing it to becut by scoring and snapping

Glass which has been subjected to a strengtheningtreatment, by heat orchemicals, which inducecompressive surface stressinto the whole surface,balanced by tensile stresswithin the body of the glass

Glass which has been subjected to a strengthening treatment, by heat orchemicals, which inducecompressive surface stressinto the whole surface, balanced by tensile stresswithin the body of the glass

JGJ 102---

Surface compressionof 24-60MPa

>90MPa


Deflection limitGlass edge

deflection limitUltimate limit

state

ASTM E1300 N.A L/175 Unfactored

AS 1288 L/60 for typical L/180 1.2G+1.5Q

L/30 for cantilevered

BS 6262/ 5516 Min. (L2/125x1000) for <=3m L/125 for monolitic ---

Min. (L2/175x1000+12, 40mm) for >3m L/175 for DGU

Min. (L2/175x1000, 20mm) for DGU

TRLV L/100 min (L/200, 15mm) Unfactored

prEN 16612/16613 min (L/65, 50mm) --- 1.1G+1.2Q

JGJ 102 L/60 L/200 1.2G+1.4Q


Allowable stress (MPa)(Short-term load)

Away from edge At edgeAN HS FT AN HS FT

ASTM E1300 23.3 46.6 91.3 18.3 36.5 73AS 1288 c1.[ -9.85ln t +71.34 ] c1.[ -7.88ln t +57.07 ]

c1=1 c1=1.6 c1=2.5 c1=1 c1=1.6 c1=2.5BS 6262/ 5516 --- --- --- --- --- ---TRLV 18 --- 50 --- --- ---prEN 16612/16613 28 49 90.5 --- --- ---JGJ 102 28 56 84 20 40 59


Load distribution

Laminated DGU

Short-term load Medium/ long-term load

ASTM E1300 Total thickness --- ---

AS 1288 Total minimum thickness t3/∑ti3 1.25Qt3/∑ti

3

BS 6262/ 5516 --- --- ---

TRLV Total thickness Total thickness t3/∑ti3

prEN 16612/16613 Effective thickness δ1+φδ2

he,SLS= 3√[∑khk

3+12ω(hkh2

m,k)] where δi=hi

3/∑h3;

he,ULS,j = √[he,SLS3/(hj+2ωhm,j

)] φ=1/[1+a/a*]4;a=shorter length of the pane;

a*=28.9[sh13h23/(h13+h23)k5

JGJ 102 te,w= 3√(t13+t23+12ΤIs

) wk,1= 1.1Qt3/∑ti3 (outer lite)

t1e,σ= √[te,w3/(t1+2Τts,2)], Τ=0 for PVB wk,2= Qt3/∑ti

3 (inner lite)


Mixed thicknessesfor laminated and DGU

Width : height limitfor 4 sided

Design thickness

ASTM E1300 Yes (for lami only) --- Minimum thickness

AS 1288 Yes 1:5 Minimum thickness

BS 6262/ 5516 No 1:3.5 ---

TRLV Yes --- ---

prEN 16612/16613 Yes --- ---

JGJ 102 Yes (< 3mm) --- ---


Design of overhead glass Design of point-fixed glass Design of Glass finASTM E1300 --- --- ---

AS 1288 Angle < 75o to the horizontal --- Fin thickness > 12mm

1.1kN distributed over a circular area of 0.01m2

Friction grip joint for glass fin

Deflection limit L/240

Appendix C for LTB

BS 6262/ 5516 --- Annealed glass is not allowed Fin thickness > 15mm

Glass hole edge distance > 2x thickness

Friction grip joint for glass fin; Bolt spacing > 100mm

TRLV Angle < 80o to the horizontal --- ---

Only laminated for the lower pane

Free edge protrudes < 300mm

prEN 16612/16613 --- --- ---

JGJ 102 ---Thickness > 6mm for flat cap routel

Deflection < L/200

Thickness > 8mm for coutersunk routel

Gap between fin and facial glass >8mm

Edge distant >70mmFin thickness >12mm, breadth > 100mm


Climatic loads Design of curved glass Design breakage rateASTM E1300 No No 8 : 1000AS 1288 No Yes 1 : 1000BS 6262/ 5516 No No Not indicated

TRLV Yes Yes pf = 10-6 per year(0.05 : 1000 based on 50 year return)

prEN 16612/16613 Yes Yes Not indicatedJGJ 102 Yes Yes Not indicated


0.8x1.8x2=2.88kPa>2kPa

▪ ASTM E 1300


Z

X Y

14.2

Global Deformations

|u| [mm]

14.2

12.9

11.6

10.3

9.0

7.7

6.4

5.1

3.9

2.6

1.3

0.0

Max : 14.2

Min : 0.0

IsometricLC 1: Q

Global Deformations u

Factor of deformations: 27.00Max u: 14.2, Min u: 0.0 mm

Z

X Y

Stresses for CO3

x [MPa]

41.573

37.610

33.647

29.684

25.721

21.758

17.795

13.832

9.869

5.906

1.944

-2.019

Max : 41.573

Min : -2.019

IsometricRF-GLASS CA1

Layer No. 1, Bottom

Stresses for CO3 Sigma-x

Max Sigma-x: 41.573, Min Sigma-x: -2.019 [MPa]

▪ AS 1288


▪ BS 6262

10mm


Z

X Y

Stresses for LC1

x [MPa]

20.540

18.582

16.624

14.666

12.708

10.750

8.792

6.834

4.876

2.918

0.960

-0.998

Max : 20.540

Min : -0.998


Layer No. 1, Bottom

Stresses for LC1 Sigma-x


Z

X Y

12.9

Global Deformations

|u| [mm]

12.9

11.7

10.5

9.4

8.2

7.0

5.9

4.7

3.5

2.3

1.2

0.0

Max : 12.9

Min : 0.0

IsometricLC 1: Q



▪ TRLV


Z

X Y

14.0

Global Deformations

|u| [mm]

14.0

12.7

11.5

10.2

8.9

7.6

6.4

5.1

3.8

2.5

1.3

0.0

Max : 14.0

Min : 0.0

IsometricLC 1: Q



Z

X Y

Stresses for CO2

x [MPa]

31.632

28.617

25.601

22.586

19.571

16.555

13.540

10.525

7.509

4.494

1.479

-1.536

Max : 31.632

Min : -1.536


Layer No. 1, Bottom

Stresses for CO2 Sigma-x


▪ JGJ 102

Glass Design StandardsExample Cases

1.5mx3.5m panel in 2kPa withmonolithic heat-strengthened glass

1.6mx3.5m panel in 2.5kPa withlaminated heat strengthened glass

1.4mx3.5m panel in 2.0kPa withDGU heat strengthened glass

ASTM E1300 Glass thickness required = 8mm Glass thickness required = 5+5mm Glass thickness required = 6+6mm

*Deflection limit is not specified *Deflection limit is not specified *Deflection limit is not specified

AS 1288 Glass thickness required = 10mm Glass thickness required = 6+6mm Glass thickness required = 8+8mm

(8mm glass fails in stress) (5+5mm glass fail in stress) (6+8mm glass fail in stress)

BS 6262/ 5516 Glass thickness required = 10mm Glass thickness required = 8+8mm Glass thickness required = 8+8mm

TRLV Glass thickness required = 12mm Glass thickness required = 6+6mm Glass thickness required = 8+8mm

(10mm glass fails in deflection) (5+5mm glass fail in deflection) (6+8mm glass fail in deflection)

prEN 16612/16613 Glass thickness required = 10mm Glass thickness required = 6+6mm Glass thickness required = 6+8mm

(8mm glass fails in stress & deflection) (5+5mm glass fails in stress & deflection) (6+6mm glass fails in deflection)

JGJ 102 Glass thickness required = 10mm Glass thickness required = 8+8mm Glass thickness required = 8+8mm

(8mm glass fails in stress) (6+8mm glass fails in stress) (6+8mm glass fails in stress)


▪ AS 1288 and JGJ 102 generally most comprehensive and

balanced

▪ ASTM E 1300 least conservative

▪ BS 6262 not very comprehensive or flexible







Design of Glass Fins

▪ Lateral torsional buckling check not covered except in AS 1288

▪ Does not take the non-linear load carrying behaviour due to

imperfections, the glass strength and the interlayer

▪ Also possible to use buckling curves derived from buckling tests

and numerical FEA models

▪ Buckling curves give

reduction factors LT for

design as a function of the

slenderness ratio lLT

© A. Luible


▪ Lateral torsional

buckling check

𝑀𝐶𝑅 =

𝑔2𝐿𝑎𝑦

𝐸𝐼 𝑦 𝐺𝐽

1.7 × 𝑔3𝑦ℎ𝐿𝑎𝑦

𝐸𝐼 𝑦

𝐺𝐽


▪ Lateral torsional

buckling restraint

▪ Glass as a restraint?

▪ Restraint capacity?


▪ Redundancy check –

Laminated glass

▪ Prevent progressive

collapse

▪ Check fins with one

ply broken and

reduced safety

factors (accidental

loading)


▪ Interstorey

movement

allowance (vertical

restraint release)

© http://www.archello.com


▪ Spliced connections

© https://www.glassonweb.com


▪ Spliced connections


▪ Clamped or bolted design


▪ Clamped

or bolted

design







Bolted glass

▪ Stress

concentration

at bolt holes

Bolted glass

▪ Stress concentration at bolt holes

© Mascha Baitinger , Markus Feldmann

Bolted glass

▪ Simple theoretical approach – Multiply stress by a factor

© http://www.fracturemechanics.org

Bolted glass

▪ Simple FEA model – No holes

Bolted glass


Bolted glass


Bolted glass

▪ More refined approach – Hole and fitting

Bolted glass


Bolted glass


Bolted glass


Bolted glass

▪ Stress concentration at bolt holes – Local mesh refinement

© http://www.fracturemechanics.org

Bolted glass

▪ Load amplification factor is inaccurate (over-conservative)

▪ High sensitivity of results to mesh size

▪ Results sensibly the same between simple and complex

models







Beyond Standards

▪ Direct glass-to-glass

connections

© www.iqglassuk.com

Beyond Standards

▪ Laminated connections

Beyond Standards

▪ Laminated

connections

© EckersleyO‘Callaghan

Beyond Standards

▪ Laminated

connections


Beyond Standards

▪ All glass structures


Beyond Standards

▪ Glued

connections


Beyond Standards

▪ Chemically

tempered glass

© JSJ Jodeit

Beyond Standards

▪ Chemically

tempered glass

© http://www.xinology.com/

Beyond Standards

▪ Glass connections







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