Based on a damage evolution equation and a critical damage function model, this paper has completed the numerical simulation of ductile spall fracture. The free-surface velocity and damage distribution have been used ...Based on a damage evolution equation and a critical damage function model, this paper has completed the numerical simulation of ductile spall fracture. The free-surface velocity and damage distribution have been used to determine jointly the physical parameters D1 （the critical linking damage）, Df （the critical fracturing damage） and k （the softening rate of critical damage function model） of the critical damage function model, which are 0.11, 0.51 and 0.57 respectively. Results indicate that the parameters determined by any of shots could be applicable to the rest of other shots, which is convincing proof for the universal property of critical damage function. In our experiments, the shock pressure is about 1 GPa to 2.5 CPa. For the reason of limited pressure range, there are still some limitations in the methods of present analysis. Moreover, according to the damage evolution characteristic of pure aluminum obtained by experiments, two critical damages are obtained, which are 0.11 and 0.51 respectively. The results are coincident with the experimental ones, which indicate that the critical growth behaviour of damage occurs in the plastic metal under dynamic loading.展开更多
We give criteria when a full subcategory D of the category of groups has C-universal factorization property(C-UFP)or C-strong universal factorization property(C-SUFP)for a certain category of groups C.As a byproduct,w...We give criteria when a full subcategory D of the category of groups has C-universal factorization property(C-UFP)or C-strong universal factorization property(C-SUFP)for a certain category of groups C.As a byproduct,we give affirmative answers to three unsettled questions in[S.W.Kim,J.B.Lee,Universal factorization property of certain polycyclic groups,J.Pure Appl.Algebra 204(2006)555-567].展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 10876014)the Science and Technology Foundation of State Key Laboratory of Shock Wave and Detonation Physics (Grant No. 9140C6701010701)
文摘Based on a damage evolution equation and a critical damage function model, this paper has completed the numerical simulation of ductile spall fracture. The free-surface velocity and damage distribution have been used to determine jointly the physical parameters D1 （the critical linking damage）, Df （the critical fracturing damage） and k （the softening rate of critical damage function model） of the critical damage function model, which are 0.11, 0.51 and 0.57 respectively. Results indicate that the parameters determined by any of shots could be applicable to the rest of other shots, which is convincing proof for the universal property of critical damage function. In our experiments, the shock pressure is about 1 GPa to 2.5 CPa. For the reason of limited pressure range, there are still some limitations in the methods of present analysis. Moreover, according to the damage evolution characteristic of pure aluminum obtained by experiments, two critical damages are obtained, which are 0.11 and 0.51 respectively. The results are coincident with the experimental ones, which indicate that the critical growth behaviour of damage occurs in the plastic metal under dynamic loading.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2016R1D1A1B03931764)supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2016R1D1A1B03932318).
文摘We give criteria when a full subcategory D of the category of groups has C-universal factorization property(C-UFP)or C-strong universal factorization property(C-SUFP)for a certain category of groups C.As a byproduct,we give affirmative answers to three unsettled questions in[S.W.Kim,J.B.Lee,Universal factorization property of certain polycyclic groups,J.Pure Appl.Algebra 204(2006)555-567].
