含均布多轴向表面裂纹厚壁圆筒结构安全性评价  

Safety Assessment of Thick Walled Cylinders with Multiple Axial Surface Cracks

作　　者：秦晓峰[1] 谢里阳[1] 何雪浤[1] 

机构地区：[1]东北大学机械工程与自动化学院,辽宁沈阳110819

出　　处：《压力容器》2013年第3期57-62,共6页Pressure Vessel Technology

基　　金：国家高技术研究发展计划(863计划)项目(2012AA040104)

摘　　要：轴向表面裂纹对受内压厚壁圆筒结果的安全具有很大的影响。在分析含均布多轴向表面裂纹厚壁圆筒裂纹数目对尖端应力强度因子影响规律的基础上,对外径相同、含均布多轴向表面裂纹厚壁圆筒及以裂纹尖端到厚壁圆筒中心距离为内径厚壁圆筒在受相同内压情况下的最大周向应力进行了对比分析,结果表明:厚壁圆筒裂纹尖端应力强度因子随裂纹数目的增加而逐渐减小并趋于一恒定值,应力强度因子随裂纹数目的减小只是裂纹扩展速度或扩展可能性的减小,含裂纹厚壁圆筒的最大周向应力在N=2时最大,且当N≥2时随着裂纹数目的增加而减小,但仍大于等效减薄厚壁圆筒的最大周向应力,厚壁圆筒的安全性仍小于以等效减薄后的光滑厚壁圆筒。The influences of multiple axial surface cracks on the safety of thick walled cylinders are impor- tant. The varies of stress intensity factors of multiple axial surface cracks along with the numbers of the cracks in the cylinders were analyzed with finite element method. Maximum circular stress of the cylinders with multiple cracks and cylinders with the inner radial equal to the distance from crack tip to the center of the cylinders with cracks were also evaluated. The results reveal that the stress intensity factors of multi- ple cracks decreased with the increase of the cracks＇ number. The decrease of tress intensity factors just imply the propagate velocity decrease of the cracks. Also the maximum circular stress of cylinders with multiple cracks has the peak point when the crack number N = 2 and the intensity of the stress decrease with the increase of the cracks＇ number. But it always higher than the maximum circular stress of cylinders whose inner radial equal to the distance from crack tip to the center of the cylinders with cracks. The safe- ty of cylinders with multiple cracks is lower than the equivalent ones without cracks.

关 键 词：多轴向表面裂纹 应力强度因子 有限元法 最大周向应力 

分 类 号：TH114[机械工程—机械设计及理论] O346.1[理学—固体力学]