基于有限元的混凝土梁受剪承载力分析

发布时间：2018-05-09 06:37

本文选题：混凝土梁 + 受剪承载力　；参考：《华南理工大学》2015年硕士论文

【摘要】：钢筋混凝土结构受剪性能的研究已有百余年历史,但由于其破坏形态复杂,影响因素众多,对受剪机理的认识还存在不足,至今尚未找到一种合理的理论模型去很好地预测结构的受剪性能。非线性有限元方法的快速发展为钢筋混凝土结构受剪性能的研究注入新的活力,在非线性有限元软件计算中,采用不同的混凝土等材料的本构模型计算结果往往不同,甚至有较大的差别。基于此,本文研究的主要内容有:(1)介绍几种主要的受剪分析方法,如桁架理论、极限平衡理论、塑性理论、非线性有限元分析法等。混凝土的本构模型对钢筋混凝土结构的非线性分析的准确性有重大的影响,因此对已有的理论模型如弹性理论、非线性弹性理论、弹塑性理论、断裂力学理论、损伤力学理论和内时理论等做了介绍。(2)运用混凝土弹塑性模型和塑性损伤模型通过ABAQUS软件建立两个非线性有限元模型,分析钢筋混凝土梁和预应力混凝土梁的受剪性能,并与试验数据进行比对,研究模型在抗剪分析方面的适用性和可靠性。结果表明,混凝土塑性损伤模型的计算结果不仅受剪承载力与试验结果吻合,而且各根梁的破坏现象与实际试验现象也吻合,变形分析则需要注意混凝土截面开裂后的刚度折减。(3)应用显示非线性动态分析,对在地震加速度荷载作用下的钢筋混凝土梁和预应力混凝土梁进行数值模拟,分析梁的受剪性能。结果显示,在加速度荷载作用下,RC梁及PC梁的受剪承载力相对静载作用有不同程度的提升;钢筋混凝土梁在加速度荷载作用下的破坏形态与静载相比基本相同,而预应力混凝土梁在加速度荷载作用下的破坏形态与静载作用相比,则有较大不同。
[Abstract]:The shear behavior of reinforced concrete structures has been studied for more than a hundred years. However, because of its complex damage morphology and many factors affecting the shear mechanism, there are still shortcomings in the understanding of shear mechanism. So far, a reasonable theoretical model has not been found to predict the shear performance of the structure well. The rapid development of the non linear finite element method is a reinforced concrete junction. In the nonlinear finite element software calculation, the calculation results of the constitutive models of different concrete and other materials are often different and even different. Based on this, the main contents of this paper are as follows: (1) several main shear analysis methods, such as truss theory and limit equilibrium theory, are introduced. Plastic theory, nonlinear finite element analysis, and so on. The constitutive model of concrete has a great influence on the accuracy of nonlinear analysis of reinforced concrete structures. Therefore, the existing theoretical models, such as elastic theory, nonlinear elastic theory, elastoplastic theory, fracture mechanics theory, damage mechanics theory and internal time theory, are introduced. (2) Two nonlinear finite element models are established by using the concrete elastoplastic model and plastic damage model through the ABAQUS software. The shear behavior of reinforced concrete beams and prestressed concrete beams is analyzed and compared with the experimental data. The applicability and dependability of the model are studied in the shear analysis. The results show that the plastic damage model of concrete is made. The calculation results are not only in accordance with the experimental results, but also in the failure of the root beams and the actual test phenomena. The deformation analysis needs to pay attention to the stiffness reduction after the cracking of the concrete section. (3) the application of nonlinear dynamic analysis is shown to the reinforced concrete beams and prestressed concrete under the loading of seismic acceleration. The beam is simulated and the shear behavior of the beam is analyzed. The results show that the shear bearing capacity of the RC beam and the PC beam is improved to some extent under the acceleration load. The failure mode of the reinforced concrete beam under the acceleration load is basically the same as the static load, while the prestressed concrete beam is subjected to the acceleration load. The failure mode is quite different from that of static loading.

【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU375

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