Numerical damage assessment in T700/epoxy composite laminate under low and high velocity impacts using a modified hashin-puck criterion

The present study explores the mechanisms of damage propagation in T700/epoxy carbon-fiber reinforced plastic (CFRP) laminates subjected to impact, with a particular focus on low (LVI) and high velocity impact (HVI). To this end, a modified Hashin-Puck criterion was developed and validated with literature data. The nonlinear material behaviour and damage evolution were investigated through finite element (FE) simulations. The derived outcomes include impactor kinetic energy, impact force, impact duration, and damage classification and evolution at several scales within the structures, encompassing fiber failure, matrix cracking, delamination, and erosion. The results indicate that HVI impacts generates higher impact forces and energy magnitudes compared to LVI. The calculated forces ratio between HVI and LVI vary from 3.46 to 16.7, while the kinetic energy ratios range from 4.01 to 16.2, highlighting a prominent increase of impact forces with velocity. Additionally, the measured eroded distance in HVI reached 7.46 % of the specimen length, reflecting the increased material sensitivity to higher energy impacts. Furthermore, the analysis of induced damage demonstrates the model’s high accuracy in predicting experimental values and observations. Notably, it was shown effective in characterizing damage within the interlayer and across the material depth in the damaged zone.