A mixed mode I/II inelastic line spring

many practical situations a cracked component may be subjected to mixed mode deformations. One important situation where this is relevant is surface cracked tubular joints applied in the offshore industry. Mixed mode affects both the deformation characteristics and fracture initiation capacity of the component, hence, an analysis model for numerical simulation should account for this. A finite element model consisting of solid elements is one approach to solve such problems. For complex components like a tubular joint, a very efficient model is obtained by means of shell finite elements. The cracked sections may be accounted for, utilizing line spring elements, Earlier work has concentrated on the Mode 1 deformation of the line spring. In the present study a mixed mode I/II elastic-plastic line spring is derived. The performance of the simple model is compared to continuum solutions obtained by means of detailed plane strain FE analyses. Both load vs deformation and J-integral performance of the line spring are considered in the comparisons. Copyright 0 1996 Elsevier Science Ltd