混凝土的一种非相关流塑性本构模型

通过实验认识混凝土的三个特性，(1)初始屈服强度为零；(2)三向等压条件下应变和塑性应变均与应力呈线性关系；(3)有扩容出现时应力-应变曲线将进入下降段，但有下降段出现不一定出现扩容。以此为基础，采用半经验半理论的方法建立了混凝土的非相关流塑性本构模型。模型能够保证在单调加载下应力-应变曲线是光滑的，在峰值点处严格遵守Willam-Warnke三参数强度准则，在下降段有稳定的变化趋势，并能描述体积压缩和扩容现象。

A non-associated plastic constitutive model for concrete

Experimental results of concrete show that the initial yield stress is zero, the strain and plastic strain is linearly dependent on stress when there is no deviatoric stress and the softening phenomena will emerge after dilatancy but not all softening is accompanied by dilatancy. On this basis, a non\|associated constitutive model for concrete is established by means of semi\|empirical and semi\|theoretical method. The method has the properties as follows:stress\|strain curve is smooth during monotone loading; the stress at peak point obeys the law of William\|Wanke strength model for three parameters; the variation has a steady trend even in the softening period; volume compression and dilatancy can be well described.