We have proposed the reduction in triple integral to double integral that is used in multiple shear mechanism model for faster 3D nonlinear ground motion analysis. In this study, we propose reformulation of the mechanism which results in the expression of an elasto-plastic tensor as the product of strain and 4th-, 6th- and higher-order tensors. Storing these high-order tensors in a database, we can eliminate numerical computation required for the triple or double integration. Because the database is stored in the memory of a computational node, it is necessary to design the database considering the trade-off relation between the database size and the accuracy of computing the elasto-plasticity tensor. We carried out numerical experiments to verify the reformulation that uses the database for high-order tensors and to examine the performance of using the database. It is shown that the computational time is reduced to approximately 2% by using the reformulation and the database.
Shishikura et al. (2026) studied this question.