4 A simply supported beam ABCDE supports a uniformly distributed load w, as shown in Figure Q3 (a). The cross sectional area of the beam is shown in Figure Q3 (b). The material is assumed to behave linearly elastic-perfectly plastic. The beam is made from mild steel with = 220 MPa. 1) Calculate the shape factor of the cross section of the beam ii) Calculate the magnitude of w which will cause the whole flanges at section C to become fully plastic. 1m w kN/m 2 m 2m Figure Q3 (a) 1 m Flanges E Webs (8 marks) 20 60 20 All dimensions in mm Figure Q3 (b) 20 120 20