复杂载荷下含未焊透缺陷压力管道塑性极限载荷分析  

Plastic Limit Load Analysis of Pressure Pipes Containing Incomplete Welding Defects under Combined Loadings

作　　者：金志江[1] 王晓芳[1] 竺国荣 陈坡 蒋诚航[1] 万先平[1] 

机构地区：[1]浙江大学化工机械研究所,杭州310027 [2]宁波市特种设备检验研究院,宁波315020

出　　处：《机械科学与技术》2010年第6期800-804,808,共6页Mechanical Science and Technology for Aerospace Engineering

基　　金：浙江省科技计划重点项目(2007C21069);浙江省自然科学基金项目(X106871)资助

摘　　要：针对净截面垮塌(NSC)准则仅适用于拉、弯组合载荷的局限性,根据压力管道实际受力特点,提出了一种基于内压/弯矩/扭矩复杂载荷作用下的含未焊透缺陷压力管道塑性极限载荷理论分析方法及其表达式,该方法还充分考虑了管道曲率(管径比)、未焊透缺陷环向长度、深度对压力管道塑性极限载荷的影响。借助有限元分析方法对含各类未焊透缺陷的压力管道塑性极限载荷进行了数值计算并与理论值进行了比较。结果表明:该方法能较好地反映含未焊透缺陷压力管道的实际承载能力,结果可靠,可大大提高含未焊透缺陷压力管道安全评定的有效性。Net Section Collapse Criteria（ NSC） are valid only to combined tension and bending loadings.According to the real mechanic properties of pressure pipes,a new theoretic analysis method of plastic limit load for pressure pipes containing incomplete welding defects and under combined bending,torsional and internal pressure loadings is presented,and its formulas are deduced.The influence of pipe curvature,circumferential length and depth of incomplete welding defects on plastic limit load is also considered in the method.Meanwhile,the plastic limit loads are calculated by finite element method and they are compared with the theoretical values.The results show that the method can accurately reflect the real load capacity of pressure pipes containing incomplete welding defects under bending,torsional and internal pressure loadings,and it can increase the safety assessment validity for pressure pipes.

关 键 词：NSC准则 未焊透缺陷 压力管道 塑性极限载荷 安全评定 

分 类 号：TH49[机械工程—机械制造及自动化]