Impact damage characterisation of carbon fibre/epoxy composites with multi-layer reinforcement

Influence of repeated impact on damage growth in fibre reinforced polymer composites

“…1a,c). The sudden reductions of force after the achievement of the maximum value of force have been also observed by other authors [16,21,22]. They concluding that such variations of the force values rather indicate to more extensive and advanced material damage, finally reducing the rigidity and strength of the material.…”

“…In fIbre reInforced polymer composItes wpływ uderzeń wIelokrotnych na rozwój uszkodzenIa kompozytów polImerowych wzmacnIanych włóknamI* sciENcE aNd tEchNology ing and technical support trucks, foreign bodiesthrust by the engine and aircraft wheels and tyres damage [22,25]. As can be drawn from technical literature [25], completed repairs of critical elements of airframes in passenger aircrafts (Boeing 747) in course of their scheduled service life were caused by three types of damages i.e.…”

“…The interrelations between the successive f-t curves are similar in the both types of materials, which indicates their similar trends in the scope of damage propagation as a result of repeated impacts. The analysis of relationship between the initiation energy (E i ) and degradation propagation energy (E p ) is possible on the basis of the force -deflection (f-d) curves for the material in course of successive impacts [2,13,22]. Among others Sohn et al [22] described that the point of reaching maximum force (F m ) determines the areas of damage initiation energy until the maximum force point is reached, as well as the area of damage propagation energy after reaching the maximum force point (Fig.…”

“…The analysed damage surface area is one of the most frequently used evaluation criteria for the influence of low velocity impacts on the condition of composite materials structure [4,14,22]. The damage surface area determined by means of NDT methods encompasses all detectable types of damage which may occur in the composite structures.…”

Impact response of glass/epoxy laminate interleaved with nanofibrous mats

“…Ductile interleaving seems to be one of the recommended methods, in which interleaf layers of toughened materials were inserted into middle plies of the composites. Generally, thermoplastic particles and films have been used as common toughened layers (Lu et al, 1995, Sohn et al, 2000. However, difficult preparation of particles due to high toughness of thermoplastic and high thickness of films due to high viscosity of thermoplastic have limited their uses in industry.…”