Optimum design of reinforcement shapes around open-hole in laminate composite with Curvilinear fibers

Abstract

This study aims to design optimum partial reinforcement with curvilinear fibers to maximize tensile strength of laminate composites with an open-hole. The authors compared difference of strain distributions around the hole of CFRP plates with or without curvilinearly shaped reinforcement by numerical and experimental studies. In the numerical study, optimum shape of reinforcement fiber is determined by using Distributed Genetic Algorithm. Obtained fiber shape reduce maximum principal strain by 36 % compared with without reinforcement. The CFRP plate specimens based on by the numerical optimization are fabricated by the tailored fiber placement machine and VaRTM method, and strain concentration around hole is measured by the tensile test. The experimental result showed reinforcement with curvilinear fiber successfully reduced strain concentration around the hole Thus, it was revealed that the reinforcement with curvilinear fibers is effective to improve strength of open-hole laminate composites.