Simulation of Fatigue Stiffness Degradation in Prestressed Concrete Beams under Cyclic Loading  

作　　者：Junqing Lei Shanshan Cao Guoshan Xu Yun Xiao 

机构地区：[1]School of Civil Engineering,Beijing Jiaotong University [2]School of Civil Engineering,Harbin Institute of Technology

出　　处：《Journal of Harbin Institute of Technology(New Series)》2016年第1期67-74,共8页哈尔滨工业大学学报（英文版）

基　　金：Sponsored by the National Natural Science Foundation of China(Grant No.51178042;51308159;51578047);the National High Technology Research and Development Program Project(Grant No.2008AA11Z102);China Railway Corporation Research and Development of Science and Technology Plan Project(Grant No.2014G004-B);China Communications Construction Co.;LTD Science and Technology Research and Development Projects(Grant No.2014-ZJKJ-03)

摘　　要：In order to investigate and research the fatigue cracking of prestressed concrete fatigue properties and loading and stiffness degeneration process,cyclic loading tests were carried out on six prestressed concrete beams and the stiffness degradation under fatigue was investigated. A simulation model of stiffness degradation is proposed based on the stiffness analysis of the fatigue-damaged section. The elastic modulus of damaged concrete and the effective residual area of steel were introduced as well as an adjusted three-stage concrete fatigue damage evolution model. The strip method was used to analyze concrete damage due to changing stress along the depth of the beam section. The simulation and test results were compared and a method of predicting fatigue deflection was presented based on the simulation model. The predicted results were compared with that of the neural network method. It is in good agreement for the simulation results with the test results. It is only less than5% error for the simulation model which can reveal the two-stage degradation of prestressed concrete beams under cyclic loading. It is more precise for the simulation prediction method under proper conditions.In order to investigate and research the fatigue cracking of prestressed concrete fatigue properties and loading and stiffness degeneration process,cyclic loading tests were carried out on six prestressed concrete beams and the stiffness degradation under fatigue was investigated. A simulation model of stiffness degradation is proposed based on the stiffness analysis of the fatigue-damaged section. The elastic modulus of damaged concrete and the effective residual area of steel were introduced as well as an adjusted three-stage concrete fatigue damage evolution model. The strip method was used to analyze concrete damage due to changing stress along the depth of the beam section. The simulation and test results were compared and a method of predicting fatigue deflection was presented based on the simulation model. The predicted results were compared with that of the neural network method. It is in good agreement for the simulation results with the test results. It is only less than5% error for the simulation model which can reveal the two-stage degradation of prestressed concrete beams under cyclic loading. It is more precise for the simulation prediction method under proper conditions.

关 键 词：prestressed concrete beam FATIGUE stiffness degradation simulation damaged concrete elastic modulus steel effective residual area deflection prediction 

分 类 号：U441[建筑科学—桥梁与隧道工程]