纤维增强复合材料结构宏细观多尺度力学性能研究及应用

发布时间：2018-03-01 14:09

本文关键词： 复合材料细观单胞模型多尺度层合板破坏失效　出处：《西安电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：复合材料具有比重小、高比强、高比模等许多优越于传统金属材料的性能,因而在航空航天、船舶、兵器、车辆和风力发电等军民两用领域中得到了越来越广泛地应用。复合材料一般由纤维与基体两种材料性能各不相同的材料组合而成,表现出内部结构具有多尺度化、各个材料高异质化等显著特点,造成其力学性能与结构具有很高的相关性。因此,研究复合材料的力学性能需将宏观与细观相互结合起来研究。本文旨在研究增强纤维复合材料的弹性性能及复合材料层板结构的破坏强度和失效,为复合材料在工程实践中的应用提供一定理论依据。首先,从纤维增强复合材料细观尺度入手,提取能够联系宏细观两尺度的代表体积单元,根据代表体积单元划分出能够表征细观特征信息的的重复单胞。利用单胞模型基本理论建立单胞模型方法求解过程并加以改进,将改进的求解过程编写成计算程序,利用相关软件的二次开发功能从细观单胞模型入手计算宏观复合材料的力学性能并与有限元软件所计算的材料力学性能相对比,验证该方法的正确性。其次,介绍复合材料层板结构在ANSYS软件分析中的单元选择,铺层角度设置以及层板结构模型建立的方法,结合复合材料经典层合板理论,分析纤维增强复合材料层板结构各铺层的应力应变情况,研究铺层角度的不同对层板结构的力学性能所产生的影响。最后,根据复合材料的各种破坏失效判断准则,研究复合材料层板结构在拉伸载荷作用下的破坏情况及裂纹扩展。结合细观单胞模型,建立基于细观单胞模型的ANSYS\LS-DYNA联合建模方法,研究加载应变率的不同造成材料破坏强度的变化。采用实验机对材料进行加载破坏实验,测量材料的破坏强度以及观察裂纹扩展,验证所分析方法的正确性。
[Abstract]:Composite materials have many advantages over traditional metal materials, such as small specific gravity, high ratio, high specific modulus, and so on, so they can be used in aerospace, ships, weapons, etc. The composite materials are generally composed of two kinds of materials with different properties of fiber and matrix, which show that the internal structure is multi-scale, and the composite materials are widely used in the field of military and civil use, such as vehicle and wind power generation, and the composite materials are composed of two kinds of materials with different properties, such as fiber and matrix. The remarkable characteristics of high heterogeneity of each material result in the high correlation between the mechanical properties and the structure. In order to study the mechanical properties of composite materials, we need to combine macroscopic and microscopical properties. The purpose of this paper is to study the elastic properties of reinforced fiber composites and the failure strength and failure of composite laminates. It provides a theoretical basis for the application of composite materials in engineering practice. Firstly, starting with the mesoscale scale of fiber reinforced composites, the representative volume units which can be connected with macro and micro scale are extracted. According to the representative volume unit, the repeated unit cell which can represent the mesoscopic characteristic information is divided. By using the basic theory of the unit cell model, the solution process of the unit cell model method is established and improved, and the improved solution process is compiled into a calculation program. The second development function of related software is used to calculate the mechanical properties of macroscopic composite materials from the meso cell model and compared with the mechanical properties of materials calculated by finite element software to verify the correctness of the method. This paper introduces the methods of element selection, layering angle setting and building of laminate structure model in the analysis of composite laminate structure in ANSYS software, combined with the classical laminate theory of composite material. The stress and strain of each layer of fiber reinforced composite laminates are analyzed, and the influence of different laying angles on the mechanical properties of laminates is studied. Finally, according to various failure criteria of composite materials, The failure and crack propagation of composite laminated structures under tensile loading are studied. A ANSYS\ LS-DYNA combined modeling method based on meso cell model is established. The change of material failure strength caused by different loading strain rate is studied. The failure strength of material is measured and the crack propagation is observed by means of an experimental machine to verify the correctness of the analytical method.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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