Experiments and Finite Element Simulations of Composite Laminates Following Low Velocity On-Edge Impact Damage

• Published in: Polymers Vol. 14; no. 9; p. 1744
• Main Authors: Xu, Wenjun, Liu, Longquan, Xu, Wu
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25.04.2022; MDPI
• Subjects: Aircraft structures; Carbon fiber reinforced plastics; Composite materials; Compression tests; Compressive strength; Crack initiation; Energy; Experiments; Finite element method; Guide rails; Impact damage; Impact tests; Laminates; Mathematical models; Numerical analysis; Propagation; Residual energy; Residual strength; Shear strength; Simulation; Velocity; finite element simulation; compression after edge impact; composite materials; on-edge impact
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym14091744

Composites are widely used in aircraft structures that have free edges and are vulnerable to impact events during manufacturing and maintenance. On-edge impact may have a great contribution in terms of the compression strength loss of composites, but the influence remains unclear. This paper presents experiments and simulations of carbon-fiber-reinforced plastic (CFRP) materials with on-edge impact and compression after edge impact (CAEI). On-edge impact damage was introduced to the composite laminates through the drop weight method with 4, 6, 8 and 10 J impact energies, respectively. A special guide-rail-type fixture was used in the compression tests in which strain–force and load–displacement relationships were obtained. A continuous-step finite element model was proposed to simulate impact and compression. Continuum shell elements and Hashin failure criteria were used to simulate in-ply damage, and interlaminar damage was modelled by cohesive elements. The model was validated by correlating the experimental and numerical results. The investigation results revealed the relationships of the damage size and residual strength with the different impact energies. The crack length and delaminated area grow with the increase in impact energy. The residual compressive strength follows a downward trend with increasing impact energy.