自增强容器最佳超应变数值分析

Numerical analysis of autofrettaged vessel for optimum overstrain extent

高压和超高压容器的失效形式可能为静强度失效和疲劳开裂失效 ,分别从静强度和疲劳强度 2方面对自增强容器的最佳超应变进行分析。以ri=2 1mm ,K =2 2 6 2的 4 3CrNi2MoVA厚壁圆筒为例 ,根据材质的实际本构关系 ,用弹塑性有限元方法分别求得了对应最高静强度和最长疲劳寿命时所需要的超应变度。对静强度 ,计算结果明显高于视材料为理想弹塑性的解析解所求结果。对于疲劳强度 ,10 0 %的超应变度将获得最长疲劳寿命 , ≥ 6 0

The optimum overstrain extent of autofrettage vessel must be analyzed from static strength and fatigue strength as the failure of high and ultra-high pressure vessels may be resulted by static strength and fatigue crack A thick-walled cylinder was taken as an example which was made of 43CrNi2MoVA and whose r i=21mm, K =2 262 The optimum overstrain extent corresponding to the highest static strength and the longest fatigue life were obtained with finite element method based on the constitutive relationship of material The static strength is obviously higher than the analytical strength when the material was taken as elastic-perfectly plastic material, and the longest fatigue life will be obtained when the overstrain extent is 100%,it was shown that the optimum overstrain effect can be obtained when the optimum overstrain extent  ≥60%