The plastic elemental stiffness matrix was derived by plastic-hinge method. 然后用塑性铰法推导了单元的塑性刚度矩阵。
After the inelastic phase, the distributing of plastic hinges is proper and reasonable, and the requirement of ductility design of structure is satisfied. 进入塑性阶段后，塑性铰分布合理，满足了结构延性设计的要求。
