The effects of stacking sequence on the penetration-resistant behaviors of T800 carbon fiber composite plates under low-velocity impact loading

Abstract

Impact damages induced by a low-velocity impact load on carbon fiber reinforced polymer (CFRP) composite plates fabricated with various stacking sequences were studied experimentally. The impact responses of the CFRP composite plates were significantly affected by the laminate stacking sequences. Three types of specimens, specifically quasi-isotropic, unidirectional, and cross-ply, were tested by a constant impact carrying the same impact energy level. An impact load of 3.44 kg, corresponding to 23.62 J, was applied to the center of each plate supported at the boundaries. The unidirectional composite plate showed the worst impact resistance and broke completely into two parts; this was followed by the quasi-isotropic lay-up plate that was perforated by the impact. The cross-ply composite plate exhibited the best resistance to the low-velocity impact load; in this case, the impactor bounced back. Impact parameters such as the peak impact force and absorbed energy were evaluated and compared for the impact resistant characterization of the composites made by different stacking sequences.

Experimental Evaluation of Low Velocity Impact Properties and Damage Progression on Bamboo/Glass Hybrid Composites Subjected to Different Impact Energy Levels

“…Based on the first conclusion for epoxy, a comparison of the different loadings of bamboo composites made at impact energies of 2.5 J and 4.4 J is more consistent when compared to the comparison made at an impact energy of 3.75 J; these comparisons show that lower bamboo filler loading gives a stiffer projectile-to-target interaction [24]. However, at an impact energy of 5 J, the EP-BF30 could still withstand the force without breaking, while the EP-BF10 experienced total damage.…”

“…The ascending part also provides information about the impact bending stiffness of the samples. The greater the peak force, the stiffer the projectile-to-target interaction, thus shortening the contact period of the impactor onto the surface [24]. The relationship between a greater peak force and a stiffer target is a representation of a situation in which greater force is needed to initiate damage in stiffer materials.…”

“…Another important value extracted from the force-displacement graph is the energy absorbed by the samples, which can be determined from the area under this graph. The energy absorbed is the kinetic energy transferred from the impactor to the samples during impact [24]. Both the energy absorbed throughout the impact event and the energy absorbed up to the peak deformation can be obtained from the force-displacement graph as shown in Figure 1.…”

“…The open curves show that the displacement increased monotonically with a decreasing force. The penetration of the samples demonstrates a situation where the force applied exceeded the maximum allowable force for the samples [24]. Throughout the low velocity impact analysis, the full penetration events will not be discussed.…”

“…The impact energy supplied during an impact event is converted into two fractions, which are the loss elastic energy and the energy absorbed by the sample. The absorbed energy is presented by the damage mechanisms on the sample or structure, where more severe damage can be an indication of more energy being absorbed [24,26]. The severity of the damage is subject to the mechanical properties of the reinforcement and the matrix, the shape of the impactor tip, the fibre orientation, the sample's geometry and the impact energy levels [21].…”