摘要
冲击荷载作用下混凝土响应与应力状态、应变率密切相关,数值分析存在本构模型理论复杂、参数繁多,工程应用困难等问题。基于弹塑性损伤帽盖模型,针对拉伸、压缩、剪切应力状态下混凝土的损伤特征,阐明了损伤参数取值与单元尺寸的依赖关系,提出了混凝土本构模型损伤参数及率效应参数的确定方法。然后,针对冲击作用下RC构件的弯曲与剪切损伤破坏行为,基于构件冲击试验分别从损伤参数的单元尺寸依赖性、剪胀损伤模拟必要性2个方面对混凝土弹塑性损伤帽盖模型参数取值的可靠性进行了验证,并对2种常用弹塑性损伤帽盖模型进行了对比。最后,基于某大桥船撞损伤破坏事故案例,进一步对大桥的船撞破坏过程进行了模拟验证。结果表明:采用所提出损伤参数标定方法可以很好地描述冲击作用下混凝土构件及结构在不同受力状态下的损伤演化过程及动态响应,解决了弹塑性损伤帽盖模型参数过多、取值困难而不便应用问题,可为混凝土桥梁结构冲击数值分析提供参考。
The response of concrete under an impact load is closely related to the loaded stress state and the strain rate.Numerical analysis faces challenges such as constitutive model complexity,large parameter numbers,and difficulties associated with engineering applications.This paper presents a method,based on the elasto-plastic damage cap model,for determining the damage parameters and the rate-dependent parameters of the concrete constitutive model,considering the concrete damage characteristics under the stress states of tension,compression,and torsion.Then,regarding the bending and shear failure modes of reinforced concrete(RC)members subjected to impact loading,the reliability of the parameter values for the concrete constitutive model is verified and validated by experiments on the RC members.The focus is the dependency of the damage parameters on the element size and the necessity of simulating shear dilation damage.Two commonly used elasto-plastic damage cap models are also compared.Then,a navigational bridge failure accident induced by a vessel collision is simulated and verified.The results indicate that the proposed parameter calibration method effectively predicts the damage evolution and the dynamic responses of the RC members under impact loading.It addresses application challenges,such as the calibration of excessively many parameters in the elasto-plastic damage cap model,and provides a reference for the numerical analysis of impact on concrete bridge structures.
作者
宋彦臣
刘学鹏
王君杰
韩强
SONG Yan-chen;LIU Xue-peng;WANG Jun-jie;HAN Qiang(l.State Key Laboratory of Bridge Safety and Resilience,Beijing University of Technology,Beijing 100124,China;Department of Bridge Engineering,Tongji University,Shanghai 200092,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2024年第5期151-174,共24页
China Journal of Highway and Transport
基金
国家重点研发计划青年科学家项目(2022YFB2602500)
国家自然科学基金项目(52008010)。
关键词
桥梁工程
混凝土桥梁
弹塑性损伤帽盖模型
参数标定
低速冲击
仿真验证
bridge engineering
concrete bridge
elasto-plastic cap model
parameter calibration
low-velocity impact
simulation verification
作者简介
宋彦臣(1988-),男,河北石家庄人,副教授,工学博士,E-mail:songyc@bjut.edu.cn;通讯作者:王君杰(1962-),男,辽宁本溪人,教授,工学博士,E-mail:jwang@tongji.edu.cn。
