Development of computational dynamic property analytical method and tissue construction optimum design method concept on microstructure of materials for nuclear energy

Using two dimensional elasto-plastic finite element method, a stress-strain curve of the materials containing voids at boundary of crystal particles was analyzed. On the analysis, continuum dynamics, Von Mises yield condition, n-power hardening rule, repeated boundary condition and others were supposed. As a result, the following facts are found; 1) When present of helium void at the crystal particle boundary, there are two configurations dependent upon processing hardening index, 2) On a case of deformation mode in the particle, helium degradation may not consider at a range of 0.3 to 0.03 of the index, 3) On a case of deformation mode at particle boundary, effect of the index is large and total elongation value reach under 1% under 0.03 of the index, 4) On increasing particle boundary density of the void, there are found some case of recovery of total elongation value, and 5) For protection of the helium degradation, though it is substantially important not to lower the index, it is necessary to consider carefully of void expansion due to rising temperature on increasing void density. (G.K.)