Surface cracks in finite thickness plates under thermal and displacement-controlled loads – Part 1: Stress intensity factors

• Surface cracks subjected to thermal or displacement-controlled loads are analysed.
• Stress intensity factors are calculated using 3-D enriched crack tip elements.
• Differences in stress intensity factors for different loading conditions are highlighted.

In this study, surface cracks in finite-thickness plates subjected to thermal or displacement-controlled loads are considered. These loads produce a uniform or bending stress state, i.e., a linear distribution over the thickness, in the corresponding uncracked structure. Stress intensity factors are calculated using enriched crack tip finite elements and compared with those of the respective mechanical loads. It is shown that the stress intensity factors along the crack front for plates under thermal or displacement-controlled loads are lower than those of cracks under mechanical loads and that this difference increases with increasing crack size due to the increasing compliance of the structure.