0.9 m y B 2 0 F = 0.8 kN 3 60° A -X

The channel shape cross-section and the rectangular cross-section shown in the Figure Q4 are made of materials with elastic-perfectly plastic behaviour. The yield stress of the material used for the channel shape cross-section is oy = 473 MPa, whereas that used for the rectangular cross- section is 0.850y. Compute the thickness of the web, t, of the channel shape section if the two cross sections have identical plastic bending moment about the z-axis. In Figure 4, h= 77 mm, b=46 mm, a=11 mm, H=77 mm, d= 46 mm N b h a + N a | d H