Fig.11 Failure mode of J-C(v=300m/s) Fig.12 Failure mode of J-C(v=400m/s) 4. Conclusion Through the above analysis and Taylor test, in which the Taylor bar was broken like petals, Finally, conclusions are summarized: (1) Failure modes in high velocity impact problems are quite different because of choosing different fracture criterions. (2) J-C fracture criterion is the most accurate fracture criterion in four fracture criterions for ductile metal in high velocity impact problems. (3) The maximum principal stress and the equivalent plastic strain failure criterions lead to many fragments for ductile metal in high velocity impact problems. References [1] Taylor, G. The Use of Flat-Ended Projectiles for Determining Dynamic Yield Stress. I. Theoretical Considerations[J]. Mathematical and Physical Sciences, 1948, 194(1038): 289-299. [2] GR Johnson, W. C. A Constitutive Model and Data for Metals Subjected to Large strains,High Strain Rates and High Temperature[C]. Proceedings of the seventh international symposium on ballistics, Netherland. 1983. [3] GR Johnson, W. C. Fracture Characteristics of Three Metals Subjected to Various Strains, Strain Rates, Temperatures and Pressures[J]. Engineering Fracture Mechanics, 1985, 21: 31-48. [4] Holmquist, G. R. J. T. J. Evaluation of cylinder‐impact test data for constitutive model constants [J]. J Appl Phys, 1988, 64(8): 3901-3910. [5] Couque, H. On the use of the symmetric Taylor test to evaluate dynamic ductile compression fracture properties of metals.[C]. Proceedings of the 5th International Conference on Structures Under Shock and Impact, Billerica,MA, USA. 1998. [6] Yingbin Bao, T. W. On fracture locus in the equivalent strain and stress triaxiality space[J]. International Journal of Mechanical Sciences, 2004, 46 81–98. [7] Rice, J. R., Tracey, D.M. On the ductile enlargement of voids in triaxial stress fields[J]. Mech Phys Solids, 1969, 17: 210-217.
RkJQdWJsaXNoZXIy MjM0NDE=