積分点毎に材料非均質性を考慮した非均質ボクセル要素の適用可能性

抄録

Image-based modeling technique enables us to create the finite element model with real shape by using CT images. Moreover, the large-scale finite element model with billions of voxel elements can be meshed semi-automatically while the meshing of tetrahedral element in large-scale FEA is considerably difficult. However, interface between dissimilar materials of voxel element has the stepwise shape, where the incorrect stress concentration is generated. To overcome the shortcoming of the voxel element, we proposed the voxel element the material properties of which are defined in each integration point of the voxel element. Material properties of each integration point are determined based on the bi-linear interpolation of the intensity of CT images. Image-based finite element analysis was performed by using CT images of the cast aluminum alloy containing Si particle, intermetallic compounds, aluminum matrix and pore, where the interface of them is complex curved surface. Results among the 10-node tetrahedral element, the homogeneous voxel element and the heterogeneous voxel element were compared to verify the effectiveness of the proposed method. As the result, it was found that the integration point stress of the proposed model vibrated more violently than that of homogeneous voxel model in the stress concentration region of dissimilar interface, however the average element stress of both model was almost same there. Moreover, the average stress of the proposed model is similar distribution of that of 10-node tetrahedral model in the low stress region of particle/matrix interface.