Sensitivity Analysis of Material Microstructure Effects on Predicted Crack Paths Using Finite Element Simulations

Abstract

The effects of microstructure, grain and grain boundary (GB) properties on predicted damage paths and indicative crack propagation direction have been examined for a polycrystalline material using mesoscale finite element simulations. Numerical analyses were carried out on a compact tension specimen geometry containing granular mesh structures with random grain shapes and sizes of average diameter 100[Formula: see text][Formula: see text]m. Nanoindentation tests were performed to investigate the dependency of mesoscale hardness measurements on the indentation location with respect to grain and GB regions. Finite element results have shown that under tensile loading conditions, the predicted damage paths are very sensitive to the granular mesh structure, GB properties and individual grain properties. Furthermore, finite element results have revealed that the cracking mode (i.e., transgranular/intergranular) and maximum crack deviation angle are strongly dependent on the material microstructures employed in simulations.

Experimental and numerical investigation of the weld geometry effects on Type IV cracking behaviour in P91 steel

“…It has been shown in previous studies [21]- [25] that the selected element size in the present study is the smallest value using which accurate crack growth simulation results with reasonable computational times can be achieved. It is evident in the stress distribution contours plots in Figure 10 that the mesh structure can influence the local stress values in the finite element simulations while the global stress distribution maps are similar to each other.…”

“…As seen in Figure 10, a fine mesh was assigned to the HAZ region and the elements were coarsened away from the crack growth region. Following the sensitivity analysis on the mesh size from previous studies [21]- [25], a fine element size of 0.001 mm was assigned to the HAZ region.…”