The physical fields in porous materials under strong shock wave reaction are very complicated. We simulate such systems using the grain contact material point method. The complex temperature fields in the material are...The physical fields in porous materials under strong shock wave reaction are very complicated. We simulate such systems using the grain contact material point method. The complex temperature fields in the material are treated with the morphological characterization. To compare the structures and evolution of characteristic regimes under various temperature thresholds, we introduce two concepts, structure similarity and process similarity. It is found that the temperature pattern dynamics may show high similarity under various conditions. Within the same material, the structures and evolution of high-temperature regimes may show high similarity if the shock strength and temperature threshold are chosen appropriately. For process similarity in materials with high porosity, the required temperature threshold increases parabolically with the impact velocity. When the porosity becomes lower, the increasing rate becomes higher. For process similarity in different materials, the required temperature threshold and the porosity follow a power-law relationship in some range.展开更多
A virtual Taylor impact of cellular materials is analyzed with a wave propagation technique, i.e. the Lagrangian analysis method, of which the main advantage is that no pre-assumed constitutive relationship is require...A virtual Taylor impact of cellular materials is analyzed with a wave propagation technique, i.e. the Lagrangian analysis method, of which the main advantage is that no pre-assumed constitutive relationship is required. Time histories of particle velocity, local strain, and stress profiles are calculated to present the local stress-strain history curves, from which the dynamic stress-strain states are obtained. The present results reveal that the dynamic-rigid-plastic hardening （D-R-PH） material model introduced in a previous study of our group is in good agreement with the dynamic stress-strain states under high loading rates obtained by the Lagrangian analysis method. It directly reflects the effectiveness and feasibility of the D-R-PH material model for the cellular materials under high loading rates.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 10702010, 10775018, and 10771019)Science Foundation of Laboratory of Computational Physics and Science Foundation of China Academy of Engineering Physics (Grant Nos. 2009A0102005 and 2009B0101012)
文摘The physical fields in porous materials under strong shock wave reaction are very complicated. We simulate such systems using the grain contact material point method. The complex temperature fields in the material are treated with the morphological characterization. To compare the structures and evolution of characteristic regimes under various temperature thresholds, we introduce two concepts, structure similarity and process similarity. It is found that the temperature pattern dynamics may show high similarity under various conditions. Within the same material, the structures and evolution of high-temperature regimes may show high similarity if the shock strength and temperature threshold are chosen appropriately. For process similarity in materials with high porosity, the required temperature threshold increases parabolically with the impact velocity. When the porosity becomes lower, the increasing rate becomes higher. For process similarity in different materials, the required temperature threshold and the porosity follow a power-law relationship in some range.
基金supported by the National Natural Science Foundation of China(11372308 and 11372307)the Fundamental Research Funds for the Central Universities(WK2480000001)
文摘A virtual Taylor impact of cellular materials is analyzed with a wave propagation technique, i.e. the Lagrangian analysis method, of which the main advantage is that no pre-assumed constitutive relationship is required. Time histories of particle velocity, local strain, and stress profiles are calculated to present the local stress-strain history curves, from which the dynamic stress-strain states are obtained. The present results reveal that the dynamic-rigid-plastic hardening （D-R-PH） material model introduced in a previous study of our group is in good agreement with the dynamic stress-strain states under high loading rates obtained by the Lagrangian analysis method. It directly reflects the effectiveness and feasibility of the D-R-PH material model for the cellular materials under high loading rates.
