Modelling the transverse cracking in cross-ply laminates: application to fatigue

When cross-ply laminates are subjected to tensile loading, the transverse cracking is the early stage of damage which occurs. In the case of static loading, cracks are initiated on the edges of test specimens and cross instantaneously the whole width of the specimens. The analysis of the transverse cracking is then reduced to a two-dimensional problem. A generalized model of the transverse cracking, including progressive shear within the 0 degrees layers is presented. In the case of fatigue tests, matrix cracks in 90 degrees layers initiate at the free edges of test specimens and grow slowly across the specimen width as a function of cycle number. So, the analysis of transverse cracking has to be implemented using a three-dimensional model. The finite element analysis shows how it is possible to reduce this problem by dividing the test specimen into bands along its width, using then the previously derived generalized model in each band. Next, the paper presents a simulation of the progression of the damage based on a statistical distribution within the volume of the test specimen for the criterion of the damage progression. (C) 1999 Elsevier Science Ltd. All rights reserved.