Study Of Multi-angle Low-velocity Impact Damage And Residual Compression Strength At The Edges Of T300/69 Laminates

Composite materials are widely used due to their high specific strength and designable fatigue properties.However,during manufacturing and transportation,collisions with materials and dropped tools may cause visually invisible damage to composites,but by this time structural changes may have already occurred within the composite material,which can lead to unpredictable safety hazards in the later use of the material.In practical engineering applications,when composite materials are subjected to impact loads,the load size and impact angle are random and the damage pattern is complex,so it is of great theoretical and engineering significance to carry out research on the damage pattern and mechanism of multi-angle and multi-energy low-velocity impact damage to the edges of composite materials.In this paper,the low-velocity impact tests and finite element simulations of T300/69 laminates are used to study the low-energy impact behavior of multi-angle edges and the change in residual compression strength after impact,with the following details:(1)Assessment of the low-velocity impact behavior of the edge of T300/69 laminate under multiple factors.The damage characteristics of the laminate under lowvelocity multi-angle impact are analyzed,and the damage conditions at the impact point and surrounding areas are characterized by electron microscopy(SEM)scanning technology.The mechanism of low-velocity impact failure at the edge of the laminate will be elucidated.(2)Post-impact damage tolerance assessment of laminates based on residual compression strength.The laminates were subjected to compression tests under different impact conditions to obtain the residual compression strength-displacement,residual compression strength-impact energy and strength retention-impact energy relationships to investigate the effect of different impact conditions on the residual compression strength of the laminates.(3)A three-dimensional Hashin failure criterion theory based on stress description.The three-dimensional Hashin failure criterion based on stress description is used in the numerical simulations,and the simulations are carried out with the aid of ABAQUS finite element analysis software for low-velocity impact and post-impact compression tests.