Experimental and numerical study on the low velocity impact response of plain-woven CFRTP corner region

Abstract

Although corner regions exist in many composite structures, such as the wingbox, research in impact engineering is largely focused on the impact performance of plates. Corner regions are subjected to low-velocity impact frequently throughout their life cycle, making it essential to investigate the impact response of these structures to enhance their design and reliability in service. In this paper, the behavior of plain-woven carbon fiber reinforced thermoplastic composites (CFRTP) corner regions under low‐velocity impact loads is studied both numerically and experimentally. Low-velocity impact tests were performed using drop-weight impact equipment at three different energies (15 J, 30 J, and 50 J). Distributed damage and the impacted region of the specimen were determined using high-resolution X-ray CT scans. The experimentally obtained material properties were incorporated into the Viscoelastic User Material (VUMAT) subroutine within ABAQUS to simulate low-velocity impact phenomena. A finite element model (FEA) for plain-woven CFRTP was developed to simulate impact, where six intralaminar damage variables depend on the underlying damage mechanisms, and effective stresses and strains are solved using the backward Euler algorithm. The reliability of FEA was verified through a mesh sensitivity study and model validation. The investigation revealed the relationships of the damage size with the different impact energies. The FEA successfully predicted the force-time and energy-time response, as well as plastic deformation, intralaminar damage, and interlaminar damage.