抗大变形管线管应变硬化指数的确定方法研究

Study on Method as Used to Determine Strain Hardening Exponent of Linepipe with High Deformation Resistance

总结了应力-应变曲线的4种常用数学模型;针对真应力-真应变曲线的幂函数本构方程,研究了以屈强比为参数的应变硬化指数n_(H)的拟合方法,并将两种钢级管线钢实测的真应力-真应变曲线与拟合的曲线进行对比。对比分析认为:应变硬化指数n_(H)随着管线钢材料屈强比的升高而减小;由n_(H)确定的Hollomon幂函数方程能够简单准确地描述大变形管线钢的真应力-真应变曲线。

Summarized here in the paper are the four commonly-used mathematical models of stress-strain curve.In light with the power function constitutive equation of the true stress-train curve,the ftting method for the strain hardening exponent nu with the yield ratio as the parameter are studied.The measured true stress-strain curves of the linepipe as made in two diferent steel grades are compared with the ftting curves.As a result of the analysis,it is regarded that the sad strain hardening exponent n_(H)is decreased along with the increase of the yield ratio;and that the Hollomon power function equation as determined by ng can be used to simply and accurately describing the true tes-strain curve of the high deformationresistant linepipe.