+ All Categories
Home > Documents > q Factor for 200x80x25x4 With Comparison of 3

q Factor for 200x80x25x4 With Comparison of 3

Date post: 05-Mar-2016
Category:
Upload: d-srinivas
View: 6 times
Download: 0 times
Share this document with a friend
Description:
Cold formed steel Design

of 24

Transcript
  • Q factor calculation according to IS 801:1975 for columns

    Name of the member: 200x80x25x4

    Calculated Sectional Properties of the Member as per IS 811:1987

    A = 1520.96W = 200 mmB = 80 mm

    L = 25 mmT = 4 mm

    R = 6 mmr = 8 mm

    Ixx = 9182920.34Iyy = 1262661.26

    28.81

    Radius of curve = 8 mm

    MI @ centroidal axis

    Elements LengthWeb 180 0 0

    Flange 120 98 1152480Lips 30 82.5 204187.50

    Corners 50.24 94.90 452500.09TOTAL = 380.24 mm 1809167.59

    TOTAL = 2295730.09

    918.29

    Distance of the C.G. from centre of arc =

    mm2

    mm4mm4

    ryy =

    for 900 corners =

    d' from XX Ld2

    MI1 = x104 mm4

  • Mid-Line Dimensions

    Area calculations neglacting the curve effect:Centroid of the mid line section

    Elements Length LWeb 196 76

    Flange 76 76Lips 23 23

    TOTAL = 394.00 mm 23Therefore, Area = 1576

    973.39136.06

    Computation of effective widths as per IS:

    1. For Unstiffened Element, (Lips) 2. For Stiffened Elements, (Flange)

    3.75

    theirfore fc = 144Uneff length =

    if b > w, then b = wif b < w, then b =

    3. For Stiffened Elements, (Web)

    mm2

    MI1 = x 104 mm4MI2 = x 104 mm4

    w/t lip =

    if w/tlip

  • w/t = 45.00

    b/t = 40.11

    160.44 mm

    uneff length = 39.56 mm

    5.Determination of safe load,

    Length = 1000 mm

    l/r = 34.71if (l/r) < (l/r)min then, fa =

    97.04

    therefore, permissible load = 147.59

    befft =

    N/mm2

  • Q factor calculation according to IS 801:1975 for columns

    Calculated Sectional Properties of the Member as per IS 811:1987 Sectional Properties of the Member as per Mid Line

    fy = 240 A =E = 204646 W =

    B =180 mm L =

    t = 4 mm T =R =

    60 mm r =t = 4 mm Ixx =

    Iyy =15 mm

    t = 4 mm

    1.57 r*4 50.24 mm Radius of curv

    MI @ centroidal axis MI @ YY axis, axis is assumed at leftmost surface of web

    MI Elements Length Ld486000.00 Web 180 2 360

    Flange 120 40 4800562.50 Lips 30 78 2340

    Nr Corner 25.12 4.91 123.26486562.50 Far Corner 25.12 75.09 1886.34

    TOTAL = 380.24 mm 9509.60TOTAL = 527004.95

    25.00947 mm

    MI of fange @ their CG = 360005.096

    Linear Iyy = 315.67

    N/mm2N/mm2

    wweb =

    wflange =

    wlip= ryy =

    for 900 corners =

    d' from YY

    mm3

    Xcg =

  • 126.27

    Centroid of the mid line sectionXi LiXi38 288838 2888 X = 23.53299 mm76 1748 Y = 98 mm76 1748

    2. For Stiffened Elements, (Flange)

    w/t = 15

    b/t = 10.66

    42.65 mm

    Uneff length = 37.35 mm

    if b > w, then b = wif b < w, then b = 42.65 mm

    4. Determination of factor Q,

    1213.31

    MI2 = x104 mm4

    befft =

    befft=

    Aeff = mm2

  • Q = 0.80

    5. Determination of Cc and (l/r)min

    Cc = 129.79

    (l/r)min = 145.31

    5.Determination of safe load,

    kN

  • Sectional Properties of the Member as per Mid Line

    1576.00 fy = 240200 mm E = 204646

    80 mm25 mm 196 mm

    4 mm t = 4 mm6 mm8 mm 76 mm

    9733922.67 t = 4 mm1360594.95

    21 mm29.38 t = 4 mm

    8 mm 1.57 r*4 50.24

    MI @ YY axis, axis is assumed at leftmost surface of web

    720.00192000.00182520.00

    604.87141650.48517495.35

    mm2 N/mm2N/mm2

    wweb =

    wflange =mm4mm4

    wlip=

    for 900 corners =

    Ld2

    mm3

    mm3

    x 103 mm3

  • Computation of effective widths as per Mid Line:

    1. For Unstiffened Element, (Lips) 2. For Stiffened Elements, (Flange)

    5.25 w/t = 19

    b/t = 19.96

    49.00theirfore fc = 144

    Uneff length = 31.00

    if b > w, then b = wif b < w, then b =

    4. Determination of factor Q,3. For Stiffened Elements, (Web)

    1328.98

    w/t lip =

    if w/tlip

  • w/t = 49.00Q = 0.84

    b/t = 41.31

    165.25 mm 5. Determination of Cc and (l/r)min

    uneff length = 30.75 mm Cc =

    (l/r)min =

    5.Determination of safe load,

    Length = 1000 mm

    l/r = 34.03if (l/r) < (l/r)min then, fa =

    102.53

    therefore, permissible load = 161.59 kN

    befft =

    N/mm2

  • Sectional Properties of the Member as per given in IS 811:1987

    A =W =B =L =T =R =r =

    Ixx =Iyy =

    mm Radius of curve =

    Computation of effective widths as per IS:

    1. For Unstiffened Element, (Lips)

    theirfore fc =

    ryy =

    w/t lip =

    if w/tlip

  • 3. For Stiffened Elements, (Web)

    w/t =

    b/t =

    uneff length =

    5.Determination of safe load,

    Length =2. For Stiffened Elements, (Flange)

    l/r =if (l/r) < (l/r)min then, fa =

    mm therefore, permissible load =

    mm

    49.00 mm

    4. Determination of factor Q,

    befft =

    mm2

  • 5. Determination of Cc and (l/r)min

    129.79

    141.34

    5.Determination of safe load,

  • Sectional Properties of the Member as per given in IS 811:1987

    1500.00 fy = 240200 mm E = 204646

    80 mm25 mm 180 mm

    4 mm t = 4 mm6 mm8 mm 60 mm

    9030000.00 t = 4 mm1240000.00

    15 mm28.75 t = 4 mm

    8 mm 1.57 r*4 50.24 mm

    Computation of effective widths as per IS:

    1. For Unstiffened Element, (Lips) 2. For Stiffened Elements, (Flange)

    3.75 w/t = 15

    b/t = 10.66

    42.65 mm144

    Uneff length = 37.35 mm

    if b > w, then b = wif b < w, then b = 42.65 mm

    mm2 N/mm2N/mm2

    wweb =

    wflange =mm4mm4

    wlip=

    for 900 corners =

    if w/tlip

  • 4. Determination of factor Q,3. For Stiffened Elements, (Web)

    1272.3545.00

    Q = 0.8540.11

    160.44 mm 5. Determination of Cc and (l/r)min

    uneff length = 19.56 mm Cc = 129.79

    (l/r)min = 140.92

    5.Determination of safe load,

    1000 mm

    34.78if (l/r) < (l/r)min then, fa =

    102.98

    therefore, permissible load = 154.47 kN

    Aeff = mm2

    N/mm2

  • Sectional Properties of the Member as per given in IS 811:1987

  • Q factor calculation according to BS5950 for columns

    Name of the member: 200x80x25x4Sectional Properties of the Member

    A = 1500W = 200 mm 180B = 80 mm 60L = 25 mm 15T = 4 mmR = 6 mm

    Ixx = 9030000.00 fy = 240Iyy = 1240000.00 E = 204646

    1. Effctive breadth of web 2. Effctive width of flanges

    h = 0.33

    K1 = 5.71 K2 = 0.634

    therefore, K1 = 5.71 therefore, K2 =

    Pcr = 521.26 Pcr = 3288.89

    Fcr/(Pcr/Lm) = 0.40 Fcr/(Pcr/Lm) =

    beff/b = 0.983 beff/b = 1.000

    beff = 176.94 mm beff = 60.00

    Gross Area as pe Mid Line Dimension = 1576 mm2

    Lips 184Flanges 608

    web 784Total = 1576 mm2

    Reduced Area of the section = 1490.16 mm2

    mm2Webeff B1 =

    Fleff B2 =Lipeff =

    mm4mm4

  • Lips 120Corners 182.4 Table 11 page 29 IS 801:1975Flanges 480

    Web 707.76Total 1490.16 mm2

    therefore, Q = 0.95

    The Compressive Strength of the Member =

  • Q factor calculation according to BS5950 for columns

    mmmmmm

    2. Effctive width of flanges 3. Effctive width of lips

    K = 0.425 conservtive for unstiffened elements

    4 therefore, K = 0.425

    Pcr = 5591.11 N/mm2

    0.0635 Fcr/(Pcr/Lm) = 0.037

    beff/b = 1.000

    mm beff = 15.00 mm

    N/mm2N/mm2

  • 310.99 kN

  • Q factor calculation according to BS5950 for columns

    conservtive for unstiffened elements

  • Sheet1Sheet2


Recommended