INITIATION AND CRACK GROWTH PROCESS IN VISCOELASTIC ORTHOTROPIC MATERIALS

摘要

A numerical approach about the crack initiation and the crack growth process in a viscoelastic media for mixed mode configurations is proposed in this work. This numerical model couples a resolution algorithm for viscoelastic behaviour and the Mθ integral providing mixed mode separation in terms of stress intensity factors and energy release rate. The numerical application is based on the 2MCG specimen allowing, in the same time, different mixed mode ratios and crack growth stability. The algorithm, implemented in a finite element software, allows to model the crack tip advance by taking into account the crack lip decohesion in the process zone. Its size is redefined with complex stress fields in the crack tip vicinity. Finally, the crack growth speed is evaluated by operating a dichotomy resolution in the time step increment required at the crack tip advance.