ズーミング有限要素解析によるアルミニウム鋳造合金のき裂発生起点まわりの応力場の高精度化

抄録

Crack initiation in cast aluminum alloy under low-cycle fatigue loading is mainly caused by the fracture of Si particles. The fracture of Si particles is influenced by pores, aluminum particle, specimen surface and their interactions. Thus, the stress-strain field on the large part of specimens should be investigated to elucidate the fracture mechanics of Si particle. In our previous study, the large-scale image-based finite element analysis was conducted by using CT images for the large part of a specimen, where the voxel element was employed to generate the finite element mesh definitely and automatically. However, the voxel element caused the lack of accuracy of the stress along the material interface. In this study, we addressed the zooming analysis by using the result of large-scale finite element analysis to achieve the high precision of stress field. The small volume image for zooming analysis was cropped from the entire CT images, where the Si particle for the crack initiation was contained. By using the extracted CT images, the finite element model with ten-node tetrahedral element was generated. The nodal displacement on the surface of the zooming small model was imposed from the result of the finite element analysis. The comparison between the large-scale, zooming small and local small model was performed to investigate the validation of the zooming analysis. As the result, the zooming analysis could reproduce the mechanical effect on the fracture Si particle observed in the large-scale analysis and mitigate the lack of accuracy of the stress due to the voxel element.