功能梯度圆筒在力学荷载作用下的理论与数值分析

发布时间：2018-01-10 18:22

本文关键词：功能梯度圆筒在力学荷载作用下的理论与数值分析　出处：《北京交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：功能梯度材料(FGM)是一种采用了先进的复合技术,使得其组成和结构沿着厚度的方向呈现梯度的变化的材料。这种材料能够减少应力集中,改善应力分布,增强抗热性。功能梯度材料因其良好的热-力学性能被广泛应用于航天工程、电磁工程、土木工程、机械工程、生物工程、核工程,光电工程等领域。而梯度圆筒结构是一种典型的具有轴对称特征的构件,常应用于航天、机械、石油天然气、土木建筑等工程领域,比如发动机的汽缸、燃气管道、输流管道、压力容器等等。本文对由按特定体积分数下的两相材料组成的线弹性圆筒模型进行了热-力学分析。基于复合材料的细观力学方法,采用Voigt等应变理论,对功能梯度圆筒进行了受热荷载下和受内压下的弹性理论和数值分析。主要内容如下： 1、利用复合材料细观力学方法,引入某一体积分数,分别考虑两相材料的应力,认为总体材料的平均应力是由两相材料应力平均得到,并以此求解出了的功能梯度圆筒材料的受热和受内压的弹性理论解析解；在求解过程中,给出了不同边界的热传导方程,借助超几何级数,最终求得FGM圆筒受热及受内压的弹性理论解。 2、基于有限元软件ANSYS,建立分层圆筒模型,每层圆筒均由A、B两相材料复合而成。分别对圆筒模型施加热荷载和内压,计算出其应力应变数值解,并与解析解相比较,验证解析解的正确性。还通过调整两相材料参数比,泊松比和以及体积分数中的参数,分析了其应力应变的变化行为。
[Abstract]:FGM (functional gradient material) is a kind of material which uses advanced composite technology to make its composition and structure gradient along the direction of thickness. This material can reduce stress concentration. FGM is widely used in aerospace engineering, electromagnetic engineering, civil engineering, mechanical engineering, biological engineering, nuclear engineering because of its good thermo-mechanical properties. The gradient cylinder structure is a typical axisymmetric component, which is often used in aerospace, machinery, oil and gas, civil construction and other engineering fields, such as engine cylinder. Gas pipeline, flow pipeline, pressure vessel, etc. In this paper, the thermo-mechanical analysis of a linear elastic cylinder model consisting of two-phase materials with specific volume fraction is carried out. Based on the meso-mechanical method of composite materials, the Voigt iso-strain theory is adopted. The elastic theory and numerical analysis of functionally graded cylinder under thermal load and internal pressure are carried out. The main contents are as follows: 1. By introducing a certain volume fraction and considering the stress of the two-phase material, it is considered that the average stress of the whole material is obtained from the average stress of the two-phase material. The analytical solutions of the thermal and internal pressure of functionally gradient cylindrical materials are obtained. In the process of solving, the heat conduction equations with different boundaries are given. With the help of hypergeometric series, the elastic solution of the FGM cylinder subjected to heat and internal pressure is finally obtained. 2. Based on the finite element software ANSYS, the layered cylinder model is established. Each layer cylinder is composed of AZB two-phase material. The cylinder model is subjected to heating load and internal pressure respectively. The numerical solution of stress and strain is calculated and compared with the analytical solution to verify the correctness of the analytical solution. The parameters of the two-phase material ratio Poisson's ratio and volume fraction are adjusted. The variation behavior of stress and strain is analyzed.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33;TB34

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