一、前言为了找出金属在塑性加工过程中的应力、应变分布规律和力能参数等,一般都采用塑性力学中的增量理论对这些工艺过程进行理论分析。在增量理论中,材料的变形塑性特性都通过能在任何变形条件下表示出材料变形规律的本构方程来加以考虑。在冷加工过程中经常使用的强化函数σ_p(ε)就是这种本构关系的一个例子。它能表示应力σ_p和应变强度ε之间的关系。为了考虑应变率效应ε以及温度T的影响,这一本构关系式经常采用三个自变量来表示,即 I. Preface In order to find out the stress, strain distribution and force parameters in the plastic processing of metal, the incremental theory in plastic mechanics is generally used to theoretically analyze these technological processes. In incremental theory, the deformation plasticity of a material is taken into account by a constitutive equation that expresses the deformation law of the material under any deformation conditions. The strengthening function σ_p (ε), which is often used in cold working, is an example of this constitutive relationship. It shows the relationship between the stress σ_p and the strain strength ε. In order to consider the effects of strain rate effect ε and temperature T, this constitutive relation is often expressed in terms of three independent variables, namely