内壁含轴向半椭圆裂纹压力容器热弹塑性效应数值分析

Numerical Analysis of Thermo-elastic-plastic Effect of Pressure Vessel with Axial Semi-elliptical Crack on Inner Surface

基于固体材料的热弹塑性效应,采用单向耦合数值分析方法,对内壁含有轴向半椭圆裂纹压力容器在单调递增载荷下的热弹塑性效应进行了数值分析,得到了含裂纹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,获得了裂纹前缘以及与之相邻的压力容器筒体外壁节点温度分布及变化规律。结果表明,裂纹最深处的应力集中较裂纹前缘其他区域更为明显,且裂纹长度和深度都对裂纹区域以及与之相邻的筒体外壁区域的温度变化产生影响。当裂纹较小时,外壁面温度不连续范围较窄,甚至难以通过温度不连续性来判明裂纹缺陷的存在;当裂纹较大时,外壁面的温度不连续范围较广,但温度变化最大的区域始终位于与裂纹面毗邻的筒体外壁区域。所得结论可为压力容器内壁半椭圆裂纹缺陷的红外无损检测提供参考。

Based on thermo-elasic-plastic effect of solid material, the thermo-elasic-plastic effect of cylin- der pressure vessel with axial semi-elliptical crack on the inner surface under monotone increasing loading conditions was carried out with the method of unidirectional coupling numerical method, the stress and strain distribution and evolution characteristics of pressure vessel with crack defects under internal pres- sure loading conditions was obtained, the temperature distribution and its evolution rule of the nodes on crack front and the adjacent pressure vessel tube wall was won. The results show that, the stress concentra- tion on the deepest of crack front is more obvious than other regions on crack front, and the crack length and depth of crack zone have great impact on the temperature change for crack area and outside area that adjacent to crack surface of cylinder when the crack size is small, the area that temperature discontinuities on the outside wall of cylinder is very small, and even can＇t ascertain the existence of crack through the temperature discontinuities. While the crack size is larger,the temperature discontinuous range on the outside wall is larger, but the greatest changes of temperature are always these areas that adjacent to crack sur- face. The conclusions can provide theoretical reference for determine whether the pressure vessel cylinder containing axial semi-elliptical crack defects by infrared nondestructive testing method.