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摘要: 本文提出了一个用于描述动态破坏发展过程的损伤度函数。从这个损伤度函数出发，把材料特征性方程取为强化粘塑性本构方程形式，导出了薄层柱壳爆炸膨胀运动在两种近似下（恒定膨胀速度近似合恒定应变速率近似）断裂判据的解析表达式。结果分析表明，在上述条件下，存在着一个动态断裂塑性峰，在这个峰值条件的应变率下，柱壳出现贯穿断裂时刻的应变最大。以软钢为算例，本断裂判据可以比较好地解释Иванов和陈大年等给出的实验结果。这时，动态断裂塑性峰对应的应变率为4104 s-1，相应的应变约为60%~80%。Abstract: A damage-level function for describing the dynamic failure growth process is proposed in this paper. Starting from this function and using the hardening-viscoplastic constitutive equation as the material characteristic equation, analytical expressions of complete-fracture criterion of a thin cylindrical shell subjected to explosion expanding have been obtained under two approximate conditions (constant expanding velocity or constant strain rate). The analytical reslts demonstrate that there exists a maximum complete-fracture strain at an appropriate strain rate, which is called plastic peak. As an example, the results for mild steel indicate that the complete-fracture criterion derived in this article could be better to explain the experimental results given by Иванов and Chen et al. The complete-fracture plastic peak is nearly located at the point of strain rate e'*=4104 s-1 and strain *=60%~80%.
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Иванов А Г, и др. ПМТФ , Вып, 1983, 1: 112. 陈大年, 等. 爆炸与冲击, 1987, 7(1): 27. Taylor G I. in: Science Papers of Sir G I Taylor. London: Combridge University Press, 1963, Ⅲ(44): 387. Hoggatt C R, Recht R F. J Appl Phys, 1968, 39: 1856. Иванов А Г. ПП, 1976, 11. Иванов А Г. ПМТФ , 1986, 1: 146. Shockey D A, Seaman L, et al. in: Material Behavior under High Stress and Ultrahigh Loading Rates. New York and London: Plenum Press, 1983: 273. Seaman L, et al. ibid, 295. Tuler F R, Butcher B M. Int J Frac Mech, 1968, 4: 431. Сериков С В. ПМТФ , 1987: 155. Дерибас А А. Фцзцка Уирочненця ц Сеаркц Взрыеом. Наука, Новосибирск, 1980. Иванов А Г, Минеев В Н. ФГВ, 1979, 5: 70. 饭田修一, 等合编. 张质贤译. 物理学常数表. 北京: 科学出版社, 1979. Johnson J N. J Appl Phys, 1981, 52(4): 2812. -
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