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

• Published in: Materials & design 2021-04, Vol.202, p.109540, Article 109540
• Main Authors: Sun, Zhenhui, Li, Cheng, Tie, Ying
• Format: Article
• Language: English
• Subjects: CFRP laminates; Damage accumulation; Energy dissipation; Patch repair; Repeated impacts
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2021.109540

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. [Display omitted] •A 3D finite element model was performed using ABAQUS/Explicit to simulate repeated impacts of patch-repaired laminates.•Intralaminar damage was modeled using a user-written VUMAT subroutine derived from continuum damage mechanics.•The influence of impact energy on damage accumulation, energy dissipation was explored by numerical calculations.•Damage accumulation of the patch-repaired laminates is closely related to the evolution of interlaminar damage.