钨合金的冲击拉伸行为及其本构和断裂判据的表述

Shock Tensile Behaviour of Tungsten Alloy and Presentations to Its Constitutive Models and Fracture Criterion

利用飞轮式Hopkinson拉杆实验技术对钨质量分数为 93%的钨合金在 - 5 0～ 10 0℃温度范围、应变率 ε =10 2 ～ 10 3 s-1区间的动态拉伸性态进行了测试 ,提供了相应的σ -ε曲线和最大拉伸失效应变 ,并以此为依据建立了该合金动态拉伸行为的本构关系 ,提出了该合金受动载发生塑性失稳以致发生拉断的判据。利用断口分形分析理论 。

The shock tensile stress strain curves of 93% wt. tungsten alloy at different strain rates and different temperatures T were measured experimentally by use of a Hopkinson tensile bars equipment. Based on these experimental data, two constitutive models were proposed to represent the shock tensile behavior of this alloy. Besides, a linear relation between the critical strain ε 1 of plastic instability and the plastic work W l at the maximum load onset of instability was derived, so that the criterion of shock tensile fracture of the material is given in this paper. The fractal analysis to the tensile fracture was made which gives a strong support to the conclusions obtained from the macro experimental results. [