ABSTRACT The adjustable mechanical properties and brittle fracture characteristics make chopped‐fiber reinforced composites an ideal material for frangible cover structures. This study investigated the performance of chopped‐basalt fiber/epoxy composites and the frangible covers manufactured from them. Through tensile testing of four types of chopped‐fiber reinforced composites, a 6‐mm‐chopped‐basalt fiber/epoxy composite was identified as the optimal material for fabricating frangible covers. Quasi‐static bursting strength tests were conducted on the cover specimens with fiber contents ranging from 10 to 30 wt%, achieving ultimate burst strengths of 0.1–0.3 MPa while maintaining controllable failure patterns. A quantitative correlation was established between the burst strength and the geometry of structurally weakened zones. Using a brittle cracking model, finite element simulations further elucidated the mechanisms of crack initiation and propagation within stress‐concentration grooves under uniform pressure. The simulated crack paths demonstrated strong consistency with experimental results, with errors below 10%, thereby validating the adopted damage evolution model. This work provides theoretical foundations for the optimized design and control of fracture behavior in composite frangible cover structures.
Li et al. (Thu,) studied this question.