基于能量的钢筋混凝土框架节点塑性铰长度的计算方法  

Calculation Method of the Plastic Hinge Length for the Reinforced Concrete Frame Joint Based on Energy Dissipation

作　　者：冯波[1] 熊峰[1] 陈江[1] 陈文 FENG Bo;XIONG Feng;CHEN Jiang;CHEN Wen(College of Architecture&Environment,Sichuan Univ.,Chengdu 610065,China)

机构地区：[1]四川大学建筑与环境学院,四川成都610065

出　　处：《工程科学与技术》2018年第5期77-86,共10页Advanced Engineering Sciences

基　　金：国家重点研发计划资助项目(2016YFC0701400)

摘　　要：塑性铰长度是进行结构弹塑性分析时的重要参数,对于分析结果有着重要影响。目前,对塑性铰长度的计算方法主要为等效塑性铰计算方法,该方法主要从变形的角度来计算塑性铰长度,而结构的塑性铰长度应当与耗能有着密切关系,但是这种方法并未考虑耗能的影响。并且,塑性铰长度在整个加载过程中并非为一个常数,应当随着加载水平的变化而变化,而目前用于计算塑性铰长度的经验公式,仅给出了塑性铰的最终长度,并未给出其与结构的加载水平的关系,采用这样的塑性铰长度必定会造成分析精度的降低。因此,作者从能量的角度出发,建立了基于能量的钢筋混凝土梁柱节点塑性铰长度计算方法,并考虑了梁端的加载水平对梁端节点塑性铰长度的影响。通过与数值结果对比可以发现,采用该方法得到的塑性铰长度与梁端塑性发展范围吻合较好。最后,通过对18个一级框架节点的参数分析,建立起了塑性铰长度与梁端转角、配筋率和截面有效高度的关系。Plastic hinge length is an important parameter when the elastic-plastic analysis is carried out on a structure and it has an important influence on the analysis result.The calculation method for the plastic hinge length is mainly the equivalent plastic length method at present and the plastic hinge length is calculated based on the deformation of a structure.While the plastic hinge length has a close relationship with the energy dissipation of a structure,but it is not considered in the equivalent plastic hinge length method.And the plastic hinge length should not be a constant and it should vary with the loading level of a structure.However,the empirical equation used to calculate the plastic hinge length only give the final length of the plastic hinge at present,and do not provide the relationship between the plastic hinge length and the loading level.Thus,it would lead to the reduction of analysis accuracy when this kind of plastic hinge length is adopted.Hence,a plastic hinge length calculation method based on energy dissipation for the reinforced concrete beam-column joint was established,and the influence of the loading level at the beam end on the plastic hinge length was taken into account.Comparison with the analysis result,it was found that the plastic hinge length calculated by the method proposed in this paper agrees well with the range of the plastic development.At last,the relationship between the plastic hinge length and the rotation at the beam end,the reinforcement ratio as well as the effective depth of the cross section was established by means of analysis of the 18 first-grade frame joints.

关 键 词：塑性铰长度 耗能 框架节点 有限元 

分 类 号：TU375.4[建筑科学—结构工程]