FRP复合材料三角形夹芯桥面板的强度分析

发布时间：2018-12-10 17:11

【摘要】：近年来,FRP复合材料结构在海洋、航空工程以及桥梁工程等领域得到越来越多的应用。作为一种新型桥面板结构,FRP复合材料夹芯桥面板具有比强度高、可设计强、稳定性高、抗冲击性能好等优点,成为复合材料桥梁结构中主要的桥面板形式之一。准确并快速地预测FRP复合材料夹芯桥面板的强度成为其应用过程中关键问题之一。本文主要内容包括：(1)根据能量法,梁理论和变形协调条件,推导了考虑面板约束的FRP复合材料三角形夹芯桥面板的等效弹性常数计算公式。通过算例分析,证明了面板约束对FRP复合材料三角形夹芯桥的等效弹性常数有显著影响。与现有理论的计算结果对比,表明了本文的等效弹性常数公式具有更高的精度。此外,还揭示了FRP复合材料夹芯桥面板的几何参数和材料参数对其等效弹性常数的影响规律。(2)基于唯象分析法和渐进损伤理论,将FRP复合材料层合板的失效准则,刚度折减方案融入到有限元软件abaqus的用户子程序usdfld中,建立3维实体模型,分别对在单向拉伸/压缩荷载下的FRP复合材料层合板进行强度分析。通过有限元结果与实验结果对比,验证了该方法对FRP复合材料层合板的极限强度预报较为精确。此外,还研究了不同尺寸,不同铺层对FRP复合材料层合板极限强度的影响。(3)基于连续介质损伤理论和渐进损伤理论,引入内部损伤状态变量和有效应力,编写了有限元软件abaqus的用户子程序umat,将FRP复合材料失效前/后的本构关系,失效准则集成到有限元分析中,建立3维实体模型,分别对在单向拉伸/压缩荷载下的FRP复合材料层合板进行强度分析,其中：内部损伤状态变量的演化由FRP复合材料自身属性和其所处的应力应变状态共同控制。通过与实验结果对比分析,表明了该方法对FRP复合材料层合板的强度分析更加贴近实际情况,极限强度预报精度也更高。(4)对FRP复合材料三角形夹芯桥面板产品FBD600进行简化,建立3维实体模型,并结合复合材料的强度理论,对弯曲荷载下FRP复合材料三角形夹芯桥面板强度进行分析。通过与实验结果对比分析,有限元的分析结果吻合较好,并揭示了FRP复合材料三角形夹芯桥面板受弯曲荷载后的失效位置分布和损伤扩展情况。(5)根据FRP复合材料三角形夹芯桥面板夹芯层的等效弹性常数公式,将桥面板等效成3层复合材料层合板,再结合复合材料层合板的强度理论,从而实现对FRP复合材料三角形夹芯桥面板弯曲极限荷载的快速预报。通过实验结果对比,验证了该方法的有效性。
[Abstract]:In recent years, FRP composite structures have been applied more and more in ocean, aviation engineering and bridge engineering. As a new type of bridge deck structure, FRP composite sandwich deck slab has the advantages of high specific strength, high design, high stability and good impact resistance. It has become one of the main bridge deck forms in composite bridge structure. Accurate and fast prediction of the strength of FRP composite sandwich deck is one of the key problems in its application. The main contents of this paper are as follows: (1) based on the energy method, beam theory and deformation coordination conditions, the equivalent elastic constants of FRP composite triangular sandwich deck are derived. It is proved that the effective elastic constants of FRP composite triangular sandwich bridge are significantly affected by panel constraints. Compared with the calculation results of the existing theory, it is shown that the formula of equivalent elastic constant in this paper has higher accuracy. In addition, the effects of geometric and material parameters on the equivalent elastic constants of FRP composite sandwich deck panels are also revealed. (2) based on phenomenological analysis and progressive damage theory, the failure criteria of FRP composite laminates are presented. The stiffness reduction scheme is integrated into the user subroutine usdfld of the finite element software abaqus, and the 3D solid model is established. The strength analysis of FRP composite laminates under uniaxial tensile / compression loads is carried out respectively. By comparing the finite element results with the experimental results, it is verified that the method is more accurate in predicting the ultimate strength of FRP composite laminated plates. In addition, the effects of different sizes and layers on the ultimate strength of FRP composite laminates are studied. (3) based on continuum damage theory and progressive damage theory, internal damage state variables and effective stresses are introduced. The user subprogram umat, of the finite element software abaqus is written to integrate the constitutive relation of FRP composite before and after failure, and the failure criterion is integrated into the finite element analysis, and the 3D solid model is established. The strength analysis of FRP composite laminates under uniaxial tensile / compression loads is carried out respectively. The evolution of internal damage state variables is controlled by the properties of FRP composites and the stress-strain states in which they are located. By comparing with the experimental results, it is shown that the strength analysis of FRP composite laminates by this method is closer to the actual situation. The prediction accuracy of ultimate strength is also higher. (4) the FBD600 of triangular sandwich deck plate of FRP composite material is simplified, and the 3D solid model is established, and the strength theory of composite material is combined. The strength of triangular sandwich deck of FRP composite under bending load was analyzed. The results of finite element analysis are in good agreement with the experimental results. The failure location distribution and damage propagation of FRP composite triangular sandwich deck after bending load are revealed. (5) according to the equivalent elastic constant formula of sandwich layer of triangle sandwich deck plate of FRP composite material, The bridge deck plate is equivalent to a three-layer composite laminated plate and the strength theory of the composite laminated plate is combined to realize the fast prediction of the bending limit load of the triangular sandwich deck plate of FRP composite material. The effectiveness of the method is verified by comparing the experimental results.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.4;U443.31

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