Fracture Analysis for Pressure Pipe Wrapped with Carbon-Fiber Reinforced Composites

A coupled FEM/EFG numerical method is introduced to calculate the stress intensity factors（SIF） along the crack front of a cracked pressure pipe line wrapped with carbon-fiber reinforced composite material（CFRC）.Two types of crack shape,traverse through-wall crack and surface ellipse crack are considered respectively,based on which the effect of the CFRC sleeve length to the Stress Intensity Factors is numerically investigated.It shows that using the algorithm presented in this paper,the stress intensity factrs of 3D component can be calculated effectively,and the SIF of the cracked pressure pipe line repaired with CFRC decrease obviously,compared to the original cracked pipe without any repair.Better repair efficiency is obtained with the increase of the sleeve length,but when the length is increased to a certain value,the length increasing of the sleeve contributes little to the decrease of the SIF,therefore to the repair efficiency.