（图片仅供参考）
The von Mises yield criterion predicts that yielding of a ductile material begins when the second deviatoric stress invariant, [latex]J_2[/latex], reaches a critical value. It is often expressed in terms of the von Mises stress, [latex]\sigma_v[/latex], a scalar value that must be less than the material’s yield strength, [latex]\sigma_y[/latex]. Yielding occurs when [latex]\sigma_v = \sigma_y[/latex].
冯·米塞斯屈服准则，也称为最大变形能准则，是一种广泛用于预测延性材料塑性变形开始的模型。该准则假定，当材料单位体积变形的弹性应变能达到临界值时，材料开始屈服。这与静水压力能（与体积变化相关）不同，静水压力能被认为对延性金属的屈服没有贡献。
从数学角度来看，这等价于指出偏应力张量的第二不变量 J₂ 达到一个常数值。偏应力张量是总应力张量减去其静水压力分量。该准则通常用冯·米塞斯等效应力 σₑ 来表示，它是应力张量六个分量的标量组合。对于一般的三维应力状态，其计算公式为：[latex]sigma_v = sqrt{frac{1}{2}[(sigma_{11}-sigma_{22})^2 + (sigma_{22}-sigma_{33})^2 + (sigma_{33}-sigma_{11})^2 + 6(sigma_{12}^2 + sigma_{23}^2 + sigma_{31}^2)]}[/latex].
Yielding is predicted to occur when [latex]\sigma_v[/latex] equals the material’s 屈服强度, [latex]\sigma_y[/latex], which is typically determined from a simple uniaxial tensile test. In principal stress space, the von Mises criterion defines a smooth, circular cylinder whose axis is the hydrostatic line ([latex]\sigma_1 = \sigma_2 = \sigma_3[/latex]). This contrasts with the Tresca criterion, which defines a hexagonal prism. The von Mises criterion generally provides a better fit with experimental data for most ductile metals and is continuously differentiable, which is advantageous in numerical computations.
冯·米塞斯屈服准则
（如果日期未知或不相关，例如“流体力学”，则提供其显著出现的近似估计）
只有注册会员才能免费获取完整尺寸的图片和下载内容。
> 登录 <
