基于ASME应变限制准则的小冲杆试验等效断裂应变  

On the Equivalent Fracture Strain in Small Punch Test based on ASME Strain Limit Criterion

作　　者：张恩勇[1] 徐彤[2] 喻灿[1] 章骁程[1] 陈吉[1] 关凯书[1] 

机构地区：[1]华东理工大学,承压系统与安全教育部重点实验室,上海200237 [2]中国特种设备检测研究院,北京100013

出　　处：《实验力学》2014年第5期647-654,共8页Journal of Experimental Mechanics

基　　金：863项目(2012AA040105);国家科技攻关项目(2011BAK06B03)

摘　　要：小冲杆试验(Small Punch Test,SPT)技术是一种新型微试样试验技术,通过极少量材料就能得到材料的许多力学性能。本文以压力容器常用钢材Q345R为研究对象,通过ABAQUS有限元软件模拟小冲杆试验过程,得到了小冲杆试样最先失效单元的应力三轴度;然后根据ASME防止局部失效的应变限制准则中求解多轴应变极限的方法,对小冲杆试验的等效断裂应变进行了研究。研究结果表明:基于ASME应变限制准则的等效断裂应变具有较大的保守性,作者所提出的修正应变限制准则参数的方法是可行的。此外,小冲杆试样的尺寸效应对等效断裂应变也有重要影响,使得计算的等效断裂应变比有限元模拟的应变值小。Small punch test（SPT）is a new micro-sample test technology,which provides a practical method of obtaining a lot of material mechanical properties by using a very small amount of material.In this paper,taking Q345 Rcommon steel used in pressure vessel as study object,a SPT finite element model was established by ABAQUS code and the test process was simulated.Stress triaxiality of the first failed unit in SPT specimen was obtained by finite element.Then,equivalent fracture strain in small punch test was studied,based on the method for solving multi-axis strain limit in ASME strain limit criterion for protecting against local failure.Results indicate that the equivalent fracture strain based on ASME strain limit criterion is conservative,and the method proposed by authors for modifying strain limit criterion parameters is feasible.Besides,the specimen size effect in small punch test has significant influence on the equivalent fracture strain;the calculated equivalent fracture strain is smaller than that obtained from finite element simulation.

关 键 词：小冲杆试验 等效断裂应变 应变限制准则 尺寸效应 

分 类 号：TB302.3[一般工业技术—材料科学与工程]