Process‐induced residual stress analysis of reinforced layer of reinforced thermoplastic pipes

Abstract A three‐dimensional representative volume element (RVE) model combining microstructure characteristics and physics‐based material failure criteria, combined with material test and bridging model, was established to analyze the generation mechanism and distribution law of process‐induced residual stress in the reinforced layer of reinforced thermoplastic pipe (RTP). Additionally, the impact of residual stress on the mechanical behavior of the fiber prepreg tape was examined. The findings indicate that matrix residual stress primarily results from thermal effects caused by solidification shrinkage, while fiber residual stress is influenced by both winding tension and matrix solidification shrinkage. During winding, temperature and tension loads couple, leading to varying degrees of damage to the matrix and interface. Consequently, the transverse tensile strength and shear strength of the prepreg tape are notably reduced compared to cases without residual stress. Highlights Bridging theory and the RVE model are used to study the residual stress in RTP. The numerical model is validated by material experiments. The damage behavior of the reinforced layer under coupling load is studied.