内壁含轴向凹坑缺陷压力容器加载过程热弹塑性效应数值分析  

Numerical analysis of thermo-elastic-plastic effect of pressure vessel with axial slot defect on inner surface during loading process

作　　者：王为清[1] 李彦强[1] 杨立[2] 范春利[2] 

机构地区：[1]中国人民解放军91872部队 [2]海军工程大学

出　　处：《塑性工程学报》2015年第2期1-7,共7页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(50906099)

摘　　要：基于固体材料的热弹塑性效应,对内壁含有轴向椭球形凹坑缺陷的压力容器在单调递增载荷条件下的热力特性进行有限元数值求解,得到了含轴向凹坑缺陷压力容器在内压载荷作用下的应力应变分布及演化特点,获得了凹坑以及与之相邻的压力容器筒体外壁节点温度的分布及变化规律。结果表明,在内压载荷作用下,凹坑最低点始终是应力最集中的区域,且发生塑性屈服后塑性变形沿着轴向扩展较快。凹坑缺陷所对应的筒体外壁区域,在局部弯矩的作用下,其所受应力比周围其他区域低很多,从而由非均匀弹性变形产生的温度不连续现象始终存在于这一区域,且形状与凹坑形状类似。当载荷超过极限载荷时,塑性屈服将在凹坑斜方向上的筒体外壁处发生,并沿着壁厚方向和凹坑轴向扩展,最终与凹坑底部的塑性屈服区域重合,此时凹坑区域所对应的筒体外壁温度分布较为复杂,且无规则性。研究结果可为压力容器筒体内壁轴向凹坑缺陷的红外无损检测提供理论参考。Based on thermo‐elastic‐plastic effect of solid material , the thermodynamic characteristic of cylinder pressure vessel with axial ellipsoidal slot defect on inner surface under monotonic increasing loading conditions was calculated by the finite element numerical solution ,the stress and strain distribution and evolution characteristics were obtained ,the temperature distribution and its evolution rule of the nodes on the slot and the adjacent pressure vessel tube wall were calculated .The results show that ,the lowest point of the slot is always the most concentrated stress area under internal pressure loading condition ,and the plastic de‐formation expands quickly along the axial direction after yielding .Under the action of the bending moment ,in the area on cylinder outside wall that against the slot defect ,the stress is much lower than that in other surrounding areas ,thus ,the temperature dis‐continuous phenomenon produced by inhomogeneous elastic deformation always exists ,and the shape is similar to the slot shape . When the loading pressure is beyond the limit load ,the yielding occurred on the outside wall of cylinder along the oblique direction of slot ,expanded along the thickness and axial directions ,and finally overlapped with the plastic area on the bottom of slot .At this time ,the temperature distribution on the outside wall of cylinder corresponding to slot area is more complex and irregular . The conclusions can provide theoretical reference for determining whether the pressure vessel cylinder contains axial slot defect by infrared nondestructive testing method .

关 键 词：热弹塑性效应 压力容器 凹坑缺陷 数值分析 

分 类 号：O242.2[理学—计算数学] TQ053.2[理学—数学]