基于损伤演化的杆件断裂模拟方法及其应用

Simulation method for member fracture based on damage evolution and its application

建立了钢材的弹塑性损伤本构模型,将其与有限单元法中分段纤维梁模型结合,实现了杆件不同位置损伤程度评估,根据评估结果实时修正杆件特性,建立了杆件断裂数值模拟方法。将所建立的杆件断裂模拟方法应用于单调递增荷载作用下的梁系结构和地震作用下的单层网壳结构,结果表明,所建立方法可有效地模拟杆件断裂;杆件断裂突然,与其相连的节点位移及杆件应变能突增,可能导致与其相连杆件破坏;强震作用下单层网壳结构可能发生杆件断裂,导致结构局部刚度降低,引起结构倒塌破坏。

Considering damage evolution, steel segmentation fiber beam to evaluate the damage level at simulation method of member fracture was established by elastic-plastic constitutive model was built and applied to different positions of a member. Based on damage value, a modifying the member characteristics in real time. Then, the simulation method of member fracture was applied to a beam structure under a monotonously increasing load and a single- layer reticulated shell under earthquake. The analysis resuhs showed that the simulation method is able to simulate member fracture effectively ; since member fracture is sudden, node displacement and strain energy of members connected to the fractured member increase suddenly, it may lead to failure of members ; member fracture may occur in a single-layer reticulated shell under strong earthquake, then it decreases the local structural stiffness and results in structural collapse.