基于混合硬化模型的超高压泵头体自增强研究  

Research on Autofrettage for Ultra-high Pressure Pump Head Based on Hybrid Hardening Model

作　　者：李宁[1,2] 李友荣[1] 周思柱[2] 廖建敏[2] 易文君[2] 

机构地区：[1]武汉科技大学冶金装备及其控制教育部重点实验室 [2]长江大学机械工程学院

出　　处：《石油机械》2015年第2期74-78,共5页China Petroleum Machinery

基　　金：国家自然科学基金项目"超高压压裂泵自增强残余应力变化规律研究"(51374041);"十二五"国家油气重大专项"泵头体自增强技术研究"(2011ZX05048-07HZ);湖北省教育厅科研计划项目"压裂泵泵头体自增强影响因素研究"(B20121202)

摘　　要：超高压泵头体自增强分析需要准确描述材料的硬化行为和包辛格效应。在推导出混合硬化弹塑性本构关系的基础上,将开发的子程序UMAT应用于某型超高压泵头体的液压自增强弹塑性有限元分析中。提出了以节点塑性应变增量的变化情况来判断自增强残余应力是否导致反向屈服的方法。通过分析自增强压力与自增强泵头体工作时最大等效应力的关系,得出该型泵头体的最佳自增强压力。泵头体最佳自增强压力的确定应以自增强残余应力不发生反向屈服为前提,以最大工作内压作用下等效应力峰值最小为原则。研究结果表明,经过最佳自增强压力处理的泵头体在工作压力作用下,内腔最大等效应力明显下降,应力分布更加均匀。Considering that autofrettage analysis of ultra-high pressure pump head needs accurate description of hardening behavior and Bauschinger effect of materials. Based on the hybrid hardening elastoplasticity constitutive relation deduced, the user material subroutine UMAT is developed. It is applied to finite-element analysis of hy- draulic autofrettage elastoplasticity for some ultra-high pressure pump head. A method is proposed to determine whether residual stress of the autofrettage causes reverse yielding based on change of plastic strain increment for the node. Optimal autofrettage pressure of the pump head can be calculated by analyzing the relationship between auto- frettage pressure and maximum equivalent stress of the autofrettage pump head in service. Optimal autofrettage pres- sure of the pump head shall be determined under the premise that residual stress of the autofrettage causes no re- verse yielding and the equivalent stress peak is the minimum value under maximum working pressure. The results show that, after optimal autofrettage pressure processing, the pump head has maximum internal equivalent stress to be significantly reduced and stress to be distributed more uniformly under working pressure.

关 键 词：自增强 混合硬化 残余应力 泵头体 有限元 

分 类 号：TE934[石油与天然气工程—石油机械设备]