Software Verification PROGRAM NAME: ETABS 2013 REVISION NO.: 0

NZS-3404-1997 Example 002 - 1

NZS-3404-1997 Example 002 WIDE FLANGE MEMBER UNDER BENDING

EXAMPLE DESCRIPTION The frame object bending strengths are tested in this example.

A continuous column is subjected to factored moment Mx = 1000 kN-m. This example was tested using the NZS 3404-1997 steel frame design code. The design capacities are compared with independent hand calculated results.

GEOMETRY, PROPERTIES AND LOADING

L = 6 m

TECHNICAL FEATURES TESTED Section compactness check (bending) Section bending capacity Member bending capacity

Material Properties E = 200x103 MPa

v = 0.3 G = 76923.08 MPa

Loading Mx = 1000 kN-m

Design Properties fy = 250 MPa Section: 350WC197

Mx

L

A A

Section A-A

Software Verification PROGRAM NAME: ETABS 2013 REVISION NO.: 0

NZS-3404-1997 Example 002 - 2

RESULTS COMPARISON Independent results are taken from hand calculations based on the CSI steel design documentation contained in the file “SFD-NZS-3404-1997.pdf, ” which is available through the program “Help” menu.

Output Parameter ETABS Independent Percent Difference

Compactness Compact Compact 0%

Section Bending Capacity, Ms,major (kN-m) 837.5 837.5 0%

Member Bending Capacity, Mb (kN-m)

1210.6 1210.6 0%

COMPUTER FILE: NZS-3404-1997 EX002

CONCLUSION The results show an exact comparison with the independent results.

Software Verification PROGRAM NAME: ETABS 2013 REVISION NO.: 0

NZS-3404-1997 Example 002 - 3

HAND CALCULATION

Properties: Material:

fy = 250 MPa Section: 350WC197

bf = 350 mm, tf = 28 mm, h = 331 mm, tw = 20 mm

I22 = 200,000,000 mm4

Z33 = 2,936,555.891 mm2

S33 = 3,350,000 mm2

J = 5,750,000 mm4 Iw = 4,590,000,000,000 mm6

Member: le22 = 6000 mm (unbraced length)

Considered to be a braced frame

Loadings:

* 1000 kN-mmM =

This leads to:

2* 250 kN-mM =

3* 500 kN-mM =

4* 750 kN-mM =

Section Compactness: Localized Buckling for Flange:

( ) 350 20 250 5.892 250 2 28 250f w y

ef

b t ft− −

λ = = =• •

Software Verification PROGRAM NAME: ETABS 2013 REVISION NO.: 0

NZS-3404-1997 Example 002 - 4

Flange is under uniform compression, so:

9, 16, 90ep ey ewλ = λ = λ =

5.89 9e epλ = < λ = , No localized flange buckling

Flange is compact

Localized Buckling for Web:

331 250 16.55250 20 250

ye

w

fht

λ = = =

Web is under bending, so:

82, 115, 180ep ey ewλ = λ = λ =

16.55 30e epλ = < λ = , No localized web buckling

Web is compact.

Section is Compact.

Section Bending Capacity:

min( ,1.5 )e cZ Z S Z= = for compact sections 2

33 33 3,350,000 mme cZ Z= = 2

33 , 33 250 3,350,000 /1000s s major y eM M f Z= = = •

33 ,major 837.5 kN-ms sM M= =

Member Bending Capacity:

kt = 1 (Program default)

kl = 1.4 (Program default)

kr = 1 (Program default)

lLTB = le22 = 6000 mm

Software Verification PROGRAM NAME: ETABS 2013 REVISION NO.: 0

NZS-3404-1997 Example 002 - 5

21 1.4 1 6000 8400 mme t l r LTBl k k k l= = • • • =

2222

2 2w

oa oe e

EIEIM M GJl l

ππ= = +

2 5 8 2 5 12

2 2

2 10 2 10 2 10 4.59 1076,923.08 5,750,0008,400 8,400oa oM M

π • • • • π • • • •= = • +

1786.938 kN-moa oM M= =

2 2837.5 837.50.6 3 0.6 31786.938 1786.938

s ss

oa oa

M MM M

α = + − = + − 0.7954sα =

( ) ( ) ( )2 2 22 3 4

1.7 2.5* * *

mm

M

M M Mα = ≤

+ +

*

( ) ( ) ( )2 2 2

1.7 1000 1.817 2.5250 500 750

m•

α = = ≤+ +

0.7954 1.817 837.5b m s sM M= α α = • •

1210.64 kN-mbM =