Failure due to bending

    

Fig. 4-7a shows a bench which consists of wooden strips, serving as seating and backing, and a pair of concrete frames supporting the seating and backing. Fig. 4-7b shows cracks at the end of the cantilever of one of the concrete frames. The two main cracks in the upper part of the cantilever (Fig. 4-7b) are a consequence of the normal stresses induced by bending exceeding the limit stress of concrete.