Transverse cracking in CFRP cross-ply laminates with interlaminar resin layers

In recent years, interlaminar-toughened laminates have been developed in which resin rich layers are placed in interlaminar regions in order to enhance the interlaminar fracture toughness of CFRP laminates. In the present study, a predictive method is developed for transverse cracking in CFRP cross-ply laminates with interlaminar resin layers at 0/90 degrees interfaces under static tensile loading. The analysis is based on a two-dimensional approximate elastic analysis considering the interlaminar resin layers and thermal residual stresses. To predict transverse cracking, both energy and stress criteria are used. The change in thermoelastic properties of a laminate due to transverse cracking is also predicted. To investigate the validity of the analysis, loading-unloading tests are performed to obtain Young's modulus reduction as a function of the transverse crack density. The predictions of transverse crack density as a function of the laminate strain are compared with our previous experimental results. A good agreement is obtained which implies the validity of the present analysis.