橡胶集料混凝土疲劳性能的有限元分析

发布时间：2018-07-21 15:51

【摘要】：混凝土是工程常用材料,广泛应用于土木工程结构和核电站等诸多领域。对混凝土材料的力学性能及耐久性进行分析具有重要理论研究意义和实用价值。本文采用实验研究与有限元分析相结合的方法,对橡胶集料混凝土材料的基本力学性能以及橡胶集料混凝土梁的疲劳性能进行分析。首先采用橡胶粒径为5目、20目、40目和橡胶掺量为0%、10%、20%、30%、40%的橡胶集料等体积取代细骨料,按照水灰比0.45制备橡胶集料混凝土梁试件,进行橡胶集料混凝土的立方体抗压强度试验和抗折强度试验,根据力学性能确定最佳橡胶粒径为40目。然后以橡胶粒径40目和橡胶掺量为0%、10%、20%、30%、40%的橡胶集料混凝土梁进行轴压试验和四点弯曲试验,对试验现象和试验结果进行分析,将不同橡胶掺量混凝土的实验参数带入有限元软件中进行非线性分析;最后将应力应变结果以及疲劳性能参数导入疲劳分析软件中分析其疲劳性能,研究不同橡胶掺量对橡胶集料混凝土梁疲劳寿命的影响。主要研究工作包括以下几个方面:1.以橡胶粒径为5目、20目、40目和橡胶掺量为0%、10%、20%、30%、40%的橡胶混凝土试件进行立方体抗压强度试验和抗折强度试验确定最佳橡胶粒径;对多种橡胶掺量的橡胶集料混凝土梁进行轴压试验和四点弯曲试验,通过对各橡胶集料混凝土梁试验现象以及试验结果的比较,研究了橡胶掺量对橡胶集料混凝土力学性能的影响;2.通过有限元软件对不同橡胶掺量的橡胶集料混凝土梁进行非线性分析,结合试验现象研究了橡胶集料混凝土梁受弯的裂缝发展状况;根据非线性分析计算结果研究了不同橡胶掺量的橡胶集料混凝土梁的开裂荷载、极限荷载和抗裂性能等,为橡胶集料混凝土梁破坏阶段的受力情况以及破坏过程的分析提供理论基础;3.将非线性分析得出的应力应变结果以及疲劳性能参数导入疲劳分析软件分析其疲劳性能,对计算结果进行了拟合,得出了不同橡胶掺量混凝土梁的S—N曲线;对不同橡胶掺量混凝土梁的疲劳寿命计算结果和S—N曲线进行分析,找出了橡胶集料混凝土梁的疲劳寿命与橡胶掺量和应力水平之间的关系。
[Abstract]:Concrete is a common material used in engineering, widely used in civil engineering structures and nuclear power plants and many other fields. It is of great theoretical significance and practical value to analyze the mechanical properties and durability of concrete materials. In this paper, the basic mechanical properties of rubber aggregate concrete materials and the fatigue properties of rubber aggregate concrete beams are analyzed by means of the combination of experimental research and finite element analysis. At first, the rubber aggregate concrete beam specimens were prepared according to the water-cement ratio of 0.45 with rubber particle size of 5 mesh and 20 mesh of 20 mesh and rubber content of 0% 10% and 20% rubber aggregates and 40% rubber aggregates in the same volume instead of fine aggregates. The cube compressive strength test and flexural strength test of rubber aggregate concrete were carried out. According to the mechanical properties, the optimum rubber particle size was determined to be 40 mesh. Then the axial compression test and four-point bending test were carried out on the rubber aggregate concrete beam with 40 mesh rubber particle size and 0% rubber content of 10 ~ 10 ~ 20% and 40% rubber aggregate concrete beam, and the experimental phenomena and test results were analyzed. The experimental parameters of concrete with different rubber content are introduced into the finite element software for nonlinear analysis. Finally, the stress-strain results and fatigue performance parameters are introduced into the fatigue analysis software to analyze its fatigue performance. The effect of rubber content on fatigue life of rubber aggregate concrete beams was studied. The main research work includes the following aspects: 1. The best rubber particle size was determined by cube compressive strength test and flexural strength test of rubber concrete specimens with rubber diameter of 5 mesh and 20 mesh of 20 mesh and rubber content of 0 10% and 40% of rubber content. The axial compression test and four-point bending test of rubber aggregate concrete beams with various rubber content were carried out. The experimental phenomena and test results of each rubber aggregate concrete beam were compared. The effect of rubber content on the mechanical properties of rubber aggregate concrete was studied. The nonlinear analysis of rubber aggregate concrete beams with different rubber content was carried out by finite element software, and the crack development of rubber aggregate concrete beams under bending was studied in combination with the experimental phenomena. According to the results of nonlinear analysis, the cracking load, ultimate load and crack resistance of rubber aggregate concrete beams with different rubber content are studied. It provides a theoretical basis for the analysis of the failure process of rubber aggregate concrete beams during the failure stage. The stress-strain results obtained from nonlinear analysis and the fatigue performance parameters are introduced into the fatigue analysis software to analyze their fatigue properties. The calculated results are fitted and the S-N curves of concrete beams with different rubber content are obtained. The fatigue life calculation results and S-N curves of concrete beams with different rubber content were analyzed and the relationship between fatigue life of rubber aggregate concrete beams and rubber content and stress level was found out.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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