Stress concentration and strength prediction of 2×2 twill weave fabric composite with a circular hole

Abstract

Stress concentration and strength prediction of 2 × 2 twill weave carbon fiber reinforced composite specimens with different hole sizes are investigated on numerical and analytical basis. Stress distribution around the hole is obtained using Lekhnitskii’s model together with Tan’s finite width correction factor and also finite element analysis. Validity of Lekhnitskii’s formula together with Tan’s correction is demonstrated for 2 × 2 twill weave composites with different w/d ratios. Tan’s correction factor is compared with finite element analysis results at a characteristic distance away from hole tip where the stresses are important for strength prediction. Applicability of point stress criteria and average stress criteria strength prediction methods for open hole specimens to 2 × 2 twill weave material is demonstrated. The performances of the point stress criteria and average stress criteria methods are compared in the case of eccentric tension loading. All analytical and numerical results are verified by experimental study.