(Solved):   EXAMPLE 10.2 a B. b C -X The trapezoid shown is the cross section of a beam. It is formed ...

 

EXAMPLE 10.2 a B. b C -X The trapezoid shown is the cross section of a beam. It is formed by removing the top from a triangle of base B = 48 mm and height H = 60 mm. The problem is to find the height y of the trapezoid that maximizes the section modulus S = I x / C where I is the second moment of the cross-sectional area about the axis that passes through the centroid C of the cross section. By optimizing the section modulus, we minimize the maximum bending stress max = M/S in the beam, M being the bending moment.