Experimental and numerical investigations on damage accumulation and energy dissipation of patch-repaired CFRP laminates under repeated impacts

In this study, the impact response, damage accumulation, interlaminar and intralaminar energy dissipation distributions of patch-repaired carbon fiber reinforced polymer (CFRP) laminates under repeated impacts were studied by combining experimental and numerical methods. A three-dimensional finite element model (FEM) based on continuum damage mechanics (CDM) and cohesive zone model (CZM) was performed using ABAQUS/Explicit to simulate the impact experiments (at impact energy of 10 J 20 J). The influence of impact energy (5 J-15 J) on damage accumulation, interlaminar and intralaminar energy dissipation was explored by numerical calculations. It was found that the sudden drop of the force-time curve was an important signal of serious internal damage of the patch; at impact energy of 5 J-12.5 J, the impact parameters such as impact time, peak force and maximum deflection increased with the increase of impact times; at impact energy of 5 J-12.5 J, the delamination damage after the first impact and the corresponding interlaminar energy dissipation increased slightly with the increase of impact times; the delamination damage can be used as an important factor to reflect the damage accumulation degree of patch-repaired laminates under repeated impacts. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).