Computational study of tungsten cracking propagation under ELM-like high heat flux conditions

Tungsten materials are subjected to severe damage when exposed to transient high heat loads, and the crack initiation and propagation are observed experimentally based on the capillary discharge plasma device. Aiming at deep understanding the cracking behavior of tungsten-based materials under extremely high thermal load, the initiation and propagation behavior of tungsten were simulated by finite element analysis. New characteristics of cracking behavior of tungsten-based materials under high temperature gradient were founded. The variations of stress and deformation induced by thermal load exhibit five stages associated with heating and cooling processes, which influence the initiation and propagation of cracks within the material. The simulation delivers consistent results on cracking mechanism and threshold (1.0 ms, 0.5 GW·m⁻²) with experiments, showing that the edge cracks initially propagate perpendicular to the surface but parallel to the surface at a depth of ∼500 μm due to temperature (stress) gradient and surface bending, and the central crack initiated in the melting layer develops perpendicular to the surface.