Badminton racquets are relatively fragile compared to the more heavily constructed tennis or squash racquets. The badminton racquet is usually made up of graphite, a light but strong material.
The chief physical parameters of a badminton racquet is reduced weight for speed/handling yet strong enough to hold around 20-30lbs of string tension. To save weight, racquets are relatively hollow save for anti-vibration foam/glue.
Cracked racquets are usually cause by the following reasons: mishits, clashes with partner's racuqet or clash on the floor.