摘要
钢筋在拉压循环荷载作用下,会产生受压屈曲现象,其应力-应变曲线呈现受压应力软化效应,传统的钢筋滞回本构模型无法对其进行描述。在Bouc-Wen模型基础上进行修正,引入屈服后刚度比调整公式,建立考虑屈曲影响的钢筋滞回本构模型,并结合Newton-Raphson迭代法给出模型详细计算流程,该模型能够同时描述刚度退化、强度退化以及受压应力软化效应等钢筋滞回特性。模型滞回特性由7个基本参数进行控制,根据所收集的钢筋单轴拉压循环试验数据,采用遗传算法对其进行参数识别。之后考虑钢筋长细比、屈服强度以及强屈比的影响,对参数识别结果进行拟合,给出各控制参数计算公式。最后通过与试验结果进行对比,验证了所提模型的有效性。
The stress softening effect can be found in the stress-strain curve of reinforcing bar under the cyclic load of tension and compression due to buckling,but it cannot be described by the traditional hysteretic constitutive model.Based on the Bouc-Wen model,an adjust formula of stiffness ratio is introduced,and the hysteretic constitutive model of reinforcing bar considering the buckling effect is established.Moreover,a calculation flowchart based on the Newton-Raphson method is introduced to solve the proposed model.The hysteresis characteristics of the reinforcing bars,such as the stiffness degradation,strength degradation,and compressive stress softening effect,can be described effectively and controlled by seven basic parameters in the proposed model.According to,the genetic algorithm is used to analyze the collected uniaxial tension and compression test data to identify the parameters.Considering the influence of the slenderness ratio,yield strength and ultimate strength-to-yield strength ratio,the results of identification are fitted and the formulas of the control parameters are obtained.Finally,the proposed model is verified by comparing with the experimental results.
作者
仇建磊
贡金鑫
Qiu Jianlei;Gong Jinxin(Dalian University of Technology,Dalian 116024,China)
出处
《土木工程学报》
EI
CSCD
北大核心
2019年第2期11-21,共11页
China Civil Engineering Journal
基金
国家自然科学基金(51478077
51678104)
关键词
钢筋屈曲
滞回本构
受压应力软化
BOUC-WEN模型
参数识别
reinforcing bar buckling
hysteretic constitutive model
compressive stress softening
Bouc-Wen model
parameter identification
作者简介
仇建磊(1992-),男,博士研究生。主要从事混凝土结构抗震研究;通讯作者:贡金鑫(1964-),男,博士,教授。主要从事工程结构可靠性理论及混凝土结构抗震研究。
