Review of low-velocity impact properties of composite materials

Interactions between propagating cracks and bioinspired self-healing vascules embedded in glass fibre reinforced composites

“…Such damage formation can lead to significant reductions in mechanical performance whilst leaving little surface evidence of 2 the impact event; a situation termed barely visible impact damage (BVID) [1][2][3].…”

Experimental optimization of the impact energy absorption of epoxy–carbon laminates through controlled delamination

“…For some specific components, such as bumpers, armours, helmets, disposable barrier shells, etc..., the most important material requirement is the capacity to absorb a large amount of mechanical energy under impact conditions before reaching complete fracture. Most composites are brittle and so can only absorb energy in elastic deformation and through damage mechanisms, and not via plastic deformation [2]. There are five basic mechanical failure modes that can occur in a composite after the initial elastic deformation [3]: i) fibre fracture, or, for aramids, defibrilation, ii) resin crazing, microcracking and gross fracture, iii) debonding between fibre and matrix, iv) fibre pull out from the matrix, and v) delamination of adjacent plies in a laminate.…”

Influence of oxyfluorination on physicochemical characteristics of carbon fibers and their reinforced epoxy composites

“…When such materials are impacted, the transferring load is absorbed into them, affecting the residual mechanical properties. 19 The total impact energy measured, E t , is the sum of the initiation energy, E i , and the propagation energy, E p . If the material behavior is elastic to failure and the stress in the specimen is adequately described by simple beam theory, then the initiation energy in a unidirectional composite reinforced with one type of fiber is given by follow equation.…”