热—机载荷下厚壁圆筒自增强压力与安全性分析  

Investigation on Autofrettage and Safety of the Thick-walled Cylinder under Thermo-mechanical Loadings

作　　者：郑小涛[1] 轩福贞[1] 

机构地区：[1]华东理工大学承压系统安全科学教育部重点实验室,上海200237

出　　处：《机械工程学报》2010年第16期156-161,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金(50835003);上海市启明星跟踪计划(10QH1400600)资助项目

摘　　要：推导厚壁圆筒在内压及热梯度载荷作用下的最佳自增强压力,并基于ANSYS优化分析结果对理论解进行验证。同时进一步探讨循环热机载荷下自增强对厚壁圆筒安定行为的影响。结果表明,不考虑热载荷时自增强处理会增大工作状态下圆筒内外壁应力差,从而降低结构的疲劳强度;当量纲一温度tn≤0.75时,最佳自增强压力的理论解与数值解一致,最大误差不超过1%,而当0.75<tn≤1.00时二者偏差较大,但此时内外壁等效应力差很小,结构无须进行自增强处理;另外,在常内压和循环热载荷下,自增强对厚壁圆筒的安定性影响很小,工程上可根据解析解进行自增强处理,提高结构的承载能力。The optimum autofrettage pressure of the thick wall cylinder under thermo-mechanical loadings is analyzed.The theoretical solutions are compared with those numerical results obtained by optimization analysis based on ANSYS.Furthermore,the effect of autofrettage on shakedown behavior of a thick-walled cylinder under constant internal pressure and cyclic thermal load is also investigated.The results indicate that the theoretical solutions of the optimum autofrettage pressure are in good agreement with the numerical solutions and the maximum error is not greater than 1% when normalized temperature tn is ≤ 0.75,while autofrettage processing is not necessary when tn is 0.75 and ≤1.00 due to the small equivalent stress difference between the inner and outer walls.Moreover,without considering the effect of thermal load,autofrettage may increase the difference of the equivalent stress between the inner and outer walls,which decreases the fatigue strength of the thick cylinder subjected to thermo-mechanical loadings.In addition,autofrettage has little influence on shakedown behavior under cyclic thermo-mechanical loadings.

关 键 词：厚壁圆筒 自增强 安定性 ANSYS 

分 类 号：TB333[一般工业技术—材料科学与工程]