【摘要】 针对汶川地震中钢筋混凝土结构出现大量的脆性破坏,以抗震结构设计中的塑性铰为研究目标,应用ANSYS程序对框架结构中最易出现塑性铰的节点部位进行了有限元分析。计算中采用了钢筋单元与混凝土单元变形不协调模型。结果显示,引起柱端脆性破坏的原因在于节点部位梁与柱的刚度失衡,柱端延性下降。目前抗震设计规范中的"强柱弱梁"、"强剪弱弯"原则和相关措施,不能保证塑性铰一定出现在梁端,结构抗震设计中常用的本构关系模型有待改进。更多还原

【Abstract】 In connection with a mass of brittle failures of reinforced concrete constructions in Whenchuan earthquake,plastic hinge in the anti-seismic design was selected as the research object,and ANSYS procedure was implemented to conduct a finite element analysis for nodes of the framework where plastic hinges may exist.In the calculation,the model with uncoordinated strain between steel and concrete units was adopted.The results demonstrate that the plastic hinges cannot always occur at the end of the beam according to the principles of "strong column weak beam" and "strong shear weak bending" from the current seismic design code.Cause leading to brittle failure of column-end is imbalanc of rigidity between beam-end and column-end.The ordinary constitutive model in seismic codes of structre remain to be improved更多还原