非等温条件下非比例循环粘塑性本构描述

CONSTITUTIVE MODELING OF ANISOTHERMAL NONPROPORTIONAL CYCLIC VISCOPLASTICITY

为了描述在非等温非比例循环加载下的循环变形行为，本文提出了一个考虑材料非比例循环附加硬化效应、非比例循环加载历史效应和温度历史效应的粘塑性本构模型．在该模型中，引入了具有三种不同演化速率的背应力演化方程；定义了新的非比例度；为了反映非比例循环历史和温度历史的影响，引入了表现各向同性变形阻力Ｑａｓｍ，并对各向同性的表现变形阻力引入了具有先前加载历史记忆的演化方程．将本文模型用于１Ｃｒ１８Ｎｉ９Ｔｉ不锈钢高温循环变形行为描述，其预言结果与实验结果吻合得很好．

In order to describe the nonproportional cyclic deformation behavior at anisothermal condition,a viscoplastic constitutive model is introduced,which considers nonproportional cyclic additional hardening,the effects of nonproportional cyclic loading history and temperature history.In the model, the evolution equations of back stresses with three different evoluting rates are proposed;a new nonproportionality is defined.To consider the influence of nonproportional cyclic loading history and temperature history, the apparent isotropic deformation resistance parameter Qasm is given, and the evolution equations,with the memory on the previous loading history, of the apparent isotropic deformation resistance are proposed.The present model is applied to the description of complex cyclic deformation behavior of 1Cr18Ni9Ti stainless steel, and its predications are in good agreement with the experimental results.