Example G.7 Singly symmetric shape in weak axis shear

The results are generated with SDC Verifier 3.6 and calculated with FEMAP v11.0.0

Task:

Verify the available shear strength and adequacy of C9×20 ASTM A36 channel with end shears of 5.00 kips from dead load and 15.0 kips from live load in the weak direction.

Solution:

From AISC Manual Table 2-4, the material properties are as follows:

ASTM A36

Fy = 36 ksi

Fu = 58 ksi

From AISC Manual Table 1-5, the geometric properties are as follows:

C9×20

bƒ = 2.65 in.

tƒ = 0.413 in.

From Chapter 2 of ASCE/SEI 7, the required shear strength is:

Note: There are no AISC Manual Tables for weak-axis shear in channel sections, but the available strength can be determined from AISC Specification Section G7.

From AISC Specification Section G7, for weak axis shear, use AISC Specification Equation G2-1 and AISC Specification Section G2.1(b) with Aw = bƒtƒ for each flange, h/tw = b/tƒb = bƒ and kv = 1.2.

Calculate Aw (Multiply by 2 for both shear resisting elements)

Calculate Cv.

Calculate Vn.

From AISC Specification Section G1, the available shear strength is:

Example from AISC Design Examples

Material summary

Material summary

Properties Summary

Geometry Property Value
Height 9.00
Width 2.65
h 9.00
a 2.65
b 2.65
c 0.41
d 0.45
t 0.41

FEM Loads and Constraint

1..Dead load 10 kips

2..Live load 30 kips

Constraint

Check 1..ANSI / AISC LRFD 360-10

Shear

All (LS1, 17 Property Shape(s))

From Chapter 2 ASCE/SEI 7, the required shear strength is:

From AISC Specification Section G1, the available shear strength is

Comparing results of calculation in SDC Verifier and in Example G.7 we can see that values completely match.

The required shear strength is 30 kips.

The available shear strength is 42.55 kips.