Question 1 The beam of rectangular cross-section of Figure 1.1 is subjected to the bending moment 40 MNmm and the maximum shear force 150 kN. The maximum bending and shear stresses in the beam are calculated using equations 1 and 2 respectively. The maximum allowable stresses in bending and shear are 10 MPa and 2 MPa, respectively. The aim of this problem is to minimise the cross- sectional area of the beam by varying the width (mm) and height (mm) of the cross section. A further restriction is that the height A should not exceed twice the width b. The limits of the design variables are: 150