Study On Residual Compressive Strength After Low-speed Impact Of Multi-scale Phase Reinforced Composite Laminates

Continuous carbon fiber reinforced composites have excellent mechanical properties and are widely used in the industrial field.However,the performance of composite components is affected by various external forces during use,which is sensitive to low-velocity impacts.Therefore,the residual strength of composite laminates after impact have high research value.With the development of material science and technology,more and more nano-enhanced phases have been used to improve the mechanical properties of composite materials.In this paper,different volume fractions of silica nanoparticles are introduced into the resin matrix of continuous carbon fiber reinforced composites.The residual compressive strength after low-velocity impact of the multi-scale phase reinforced composite laminates was experimentally studied by comparing the load time history curve,energy history curve and load displacement curve after impact.The influence of the addition of nanoparticles on the impact resistance of the multi-scale phase reinforced composite laminates was analyzed.Ultrasonic flaw detection technology was used to quantitatively characterize the impact damage zone formed inside the laminate,and the shape of the impact damage zone was explored.The variation of the size of the damage zone with the thickness of the laminate,the impact energy and the volume fraction of the nanoparticle is summarized.In the residual compressive strength test of laminated plate specimens after low-velocity impact,the digital image correlation method was used to accurately measure the strain field in the damaged area of the laminate during the test.Based on the high-speed camera tracking the crack propagation process during laminate compression failure,the evolution of the strain field in the laminate damage region during the post-impact compression test was analyzed.Finally,through the finite element simulation method,the relationship between the damage area of composite laminates after impact and the residual compressive strength of laminates after impact was established,through the quantitative characterization of the damaged regions,The residual compressive strength prediction model of laminates was developed,and the prediction results were in good agreement with the experimental results.