Strain Energy Release Rate Analyse of Matrix Micro Cracking in Composite Cross-Ply Laminates

Abstract

The stress field distribution in composite cross ply laminates damaged by matrix cracking is analysed through an approach which uses several hypotheses to simplify the damage state. The proposed cracking criterion involves the partial components of the strain energy release rate associated with transverse and longitudinal cracking. The respective contributions of the 0° and 90° layers to the damage process are also investigated. The initiation of transverse and longitudinal cracking mechanisms is predicted. We also give an assessment of the influence of each individual component of the stress tensor on the strain energy release rate of the damaged laminate

Micromechanical prediction of damage due to transverse ply cracking under fatigue loading in composite laminates

“…Based on finite fracture view, the total energy release rate is derived for the whole laminate by equation (16) 37–39 where A is the cross section of the crack, and ΔA is the cross section of new microcracks in the unit cell. Assuming that the new microcrack will be formed in the middle of the existing microcracks and by defining the inverse of distance between two adjacent cracks as crack density parameter (ρ = 1/(2a)), after creation of a microcrack, the crack density will change from ρ to 2ρ.…”

In-situ SEM study of transverse cracking and delamination in laminated composite materials

“…Previous studies [2][3][4][5] have shown that there is a strong interaction, and hence coupling, between transverse matrix cracking and delamination. In general, transverse cracks initiate first [5,6], coalesce and grow until they extend to ply boundaries, at which point they initiate micro-delaminations. Once the transverse crack density has reached saturation, microcracking ceases and delamination becomes the dominant failure mechanism [7].…”

Composite Failures: A Comparison of Experimental Test Results and Computational Analysis Using XFEM

“…To study this phenomenon, Rebière and Gamby decomposed the strain energy release rates for different modes of fracture into components depending on the type of crack present; transverse cracks, longitudinal cracks or delamination. 11,12 Pinho et al determined the intralaminar fracture toughness of carbon/epoxy composites by using the four-point bend and compact tension tests. 13,14 Variations in mode I intralaminar and interlaminar fracture toughness have been observed.…”