The Incorporation of Localized Softening in a Constitutive Model for Frictional Materials

本研究的重点是研究一种同时产生软化和局部化现象本质的配方。三维模型将基于粘塑性，其中屈服函数除了通常的内部变量外还包含应变梯度。非局部公式回避了许多反对应变软化存在的论点。将研究一种数值方案，以获得具有局部软化特征的结构问题的解。通过比较混凝土试件和钢筋混凝土梁在横向和轴向组合荷载作用下的理论和实验数据，可以证明模型的准确性和预测软化方法的实用性。

The focus of this research is to investigate a formulation that yields simultaneously the essence of softening and localization phenomena. The three-dimensional model will be based on viscoplasticity in which the yield function contains a strain gradient in addition to the usual internal variables. The non-local formulation circumvents many of the arguments against the existence of strain softening. An investigation will be made of a numerical scheme to obtain solutions to structural problems with localized softening features. The accuracy of the model and the usefulness of the approach for predicting softening will be demonstrated by making comparisons between theoretical and experimental data on concrete specimens and on reinforced concrete beams subjected to combined transverse and axial loading.