Mode I delamination propagation of thermoplastic composite laminate at different temperatures: Experimental and numerical simulation

Abstract

Thermoplastic composites, appreciated for their lightweight, high specific strength, excellent energy absorption, and crash resistance, are gaining popularity in aerospace, automotive, and marine industries. High-temperature environments can lead to the degradation of inter-laminar stresses and component performance. To assure the credible application of thermoplastic composites during service environments, an in-depth analyze of the relationship between the inter-laminar properties and temperature is essential. In this study, the effect of temperature on the process of delamination propagation in thermoplastic composite structures was analyzed by performing delamination propagation tests of double cantilever beam (DCB) at different temperatures. The results show that temperature has an important effect on fracture toughness, delamination propagation rate, delamination propagation resistance curve (R-curve), and the number of fiber bridges. The bridging traction at the interface of the thermoplastic composite plate decreases with increasing temperature. The fracture toughness $G_I$ were reduced by 67.5%, 72.4% and 85.1% at temperatures of 40℃, 60℃ and 80℃, respectively, compared to the room temperature. Finally, the obtained traction-separation relationship was integrated into trilinear cohesive zone mode considering the effect of temperature. The numerical results were agreement with the experimental results, evidencing that the proposed trilinear cohesive zone mode was suitable for modeling the delamination propagation of thermoplastic composite laminates at high temperatures.