Modeling and experimental investigation of nonlinear behaviors for CF/PEEK thermoplastic laminated strips with perforated holes

Abstract

In this work, the effects of various notch-distribution parameters on the mechanical behavior of CF/PEEK laminates are systematically investigated to inform the design of perforated thermoplastic composite structures. A three-dimensional continuum damage model, incorporating the nonlinear shear response of thermoplastic composites, is developed. Distinct damage modes and morphology of fracture surface are investigated by experimental observation. Progressive damage evolution under tensile loading is characterized via high-fidelity numerical simulations and validated against experimental measurements using digital image correlation. The key design variables, including width to diameter ratio, hole amount in transverse direction and longitudinal direction, uniformity coefficient in longitudinal direction and layup angle—are all examined using a three-level parametric study. Numerical and experimental implementations of the proposed approach enabled the influence of load-carrying capacities and damage mechanisms. The comparison of experimental and simulated results demonstrates a good agreement. Moreover, the significant stress-shielding effects are conducted from the observation of the damage initiation around the outermost and isolated holes. The relevance of this influence is related to geometry and arrangement parameters. These insights offer practical guidance for the rationalization of open-hole layouts in lightweight high-performance composite structures.