多场耦合下含孔隙的热塑性聚合圆筒的力学行为研究
发布时间：2018-07-23 11:54
【摘要】：复合材料是由两种或两种以上有着不同物理和化学性质的材料按一定的比例复合而成的。一般来讲,热塑性聚合物基复合材料(以下简称热塑性聚合材料)由两种材料复合而成,例如,纤维作为增强体,树脂等聚合材料作为基体。因为热塑性聚合材料具有高强度、低密度、良好的耐腐蚀性以及良好的环保性能等其它优良的力学和物理性能,它们在航空航天、生物工程、能源工程以及生活等领域得到了广泛应用。对于热塑性聚合材料,新型增强体和基体的研究一直以来是研究人员得到新型材料的途径。然而,研究人员一般容易忽视的问题是对热塑性聚合材料中孔隙率的研究。本文以含孔隙的热塑性聚合圆筒结构为研究对象,假设热塑性聚合材料是各向同性的,各物性参数随孔隙率的变化而变化,基于经典的弹性力学理论,得到了在热机和湿热耦合场下,热塑性聚合圆筒的动态响应控制方程。其次,本文利用Hankel变换和Laplace变换原理求得了热机耦合下弹性范围内动态问题的解析解,利用有限差分法和Newmark法求得了热机耦合下粘弹性范围内和湿热耦合下弹性范围内动态问题的数值解。通过以上方法,本文第二章具体分析了在热机耦合下含孔隙的无限长热塑性聚合圆筒的动态响应,得到了孔隙率对位移和应力振动频率的影响规律;第三章具体分析了在热机耦合下含孔隙的无限长热塑性聚合圆筒的粘弹性动力学行为,得到了孔隙率对热塑性聚合材料粘弹性的影响规律;第四章和第五章具体分析了在湿热耦合下含孔隙的无限长热塑性聚合圆筒的动态响应以及在湿热耦合下含孔隙的有限长双层圆筒的动力学行为,得到了孔隙率对热塑性聚合材料湿热传导的影响规律。除了孔隙率以外,本文还分别讨论了机械荷载、温度和湿度荷载以及厚度比等因素对热塑性聚合圆筒力学性能的影响。本文的研究工作将丰富和发展复合材料、结构动力学和热弹性力学。同时本文所得到的结论为热塑性聚合材料的制造和进一步研究提供一定的理论依据,并具有一定的工程实际应用价值。
[Abstract]:Composite materials are composed of two or more materials with different physical and chemical properties. Generally speaking, thermoplastic polymer matrix composites (hereinafter referred to as thermoplastic polymeric materials) are composed of two kinds of materials, for example, fibers as reinforcements, resins and other polymeric materials as matrix. Because thermoplastic polymeric materials have high strength, low density, good corrosion resistance, good environmental protection and other excellent mechanical and physical properties, they are in aerospace, bioengineering, Energy engineering and life and other fields have been widely used. For thermoplastic polymeric materials, the study of new reinforcements and substrates has always been the way for researchers to obtain new materials. However, the problem that researchers tend to ignore is the study of porosity in thermoplastic polymeric materials. In this paper, the thermoplastic polymerized cylinder structure with pores is taken as the object of study. It is assumed that the thermoplastic polymeric material is isotropic, and the physical parameters vary with the porosity, based on the classical theory of elasticity. The governing equation of dynamic response of thermoplastic polymerized cylinder is obtained under the coupling field of heat engine and wet heat. Secondly, the analytical solution of the dynamic problem in the elastic range under thermo-mechanical coupling is obtained by using the Hankel transform and the Laplace transformation principle. By using the finite difference method and the Newmark method, the numerical solutions of the dynamic problems in the viscoelastic range and the hygrothermal coupling range are obtained. In the second chapter, the dynamic response of infinite thermoplastic polymerized cylinder with pores under thermo-mechanical coupling is analyzed, and the effect of porosity on displacement and stress vibration frequency is obtained. In chapter 3, the viscoelastic dynamic behavior of infinite thermoplastic polymerized cylinder with pores under thermo-mechanical coupling is analyzed, and the influence of porosity on viscoelasticity of thermoplastic polymeric materials is obtained. In the fourth and fifth chapters, the dynamic response of infinite thermoplastic polymerized cylinder with pores and the dynamic behavior of finite length double-layer cylinder with pores under the hygrothermal coupling are analyzed in detail. The effect of porosity on wet heat conduction of thermoplastic polymeric materials was obtained. In addition to porosity, the effects of mechanical load, temperature and humidity load and thickness ratio on the mechanical properties of thermoplastic polymerized cylinder are discussed. The research work in this paper will enrich and develop composite materials, structural dynamics and thermoelastic mechanics. At the same time, the conclusions obtained in this paper provide a certain theoretical basis for the manufacture and further study of thermoplastic polymeric materials, and have a certain practical application value in engineering.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33
[Abstract]:Composite materials are composed of two or more materials with different physical and chemical properties. Generally speaking, thermoplastic polymer matrix composites (hereinafter referred to as thermoplastic polymeric materials) are composed of two kinds of materials, for example, fibers as reinforcements, resins and other polymeric materials as matrix. Because thermoplastic polymeric materials have high strength, low density, good corrosion resistance, good environmental protection and other excellent mechanical and physical properties, they are in aerospace, bioengineering, Energy engineering and life and other fields have been widely used. For thermoplastic polymeric materials, the study of new reinforcements and substrates has always been the way for researchers to obtain new materials. However, the problem that researchers tend to ignore is the study of porosity in thermoplastic polymeric materials. In this paper, the thermoplastic polymerized cylinder structure with pores is taken as the object of study. It is assumed that the thermoplastic polymeric material is isotropic, and the physical parameters vary with the porosity, based on the classical theory of elasticity. The governing equation of dynamic response of thermoplastic polymerized cylinder is obtained under the coupling field of heat engine and wet heat. Secondly, the analytical solution of the dynamic problem in the elastic range under thermo-mechanical coupling is obtained by using the Hankel transform and the Laplace transformation principle. By using the finite difference method and the Newmark method, the numerical solutions of the dynamic problems in the viscoelastic range and the hygrothermal coupling range are obtained. In the second chapter, the dynamic response of infinite thermoplastic polymerized cylinder with pores under thermo-mechanical coupling is analyzed, and the effect of porosity on displacement and stress vibration frequency is obtained. In chapter 3, the viscoelastic dynamic behavior of infinite thermoplastic polymerized cylinder with pores under thermo-mechanical coupling is analyzed, and the influence of porosity on viscoelasticity of thermoplastic polymeric materials is obtained. In the fourth and fifth chapters, the dynamic response of infinite thermoplastic polymerized cylinder with pores and the dynamic behavior of finite length double-layer cylinder with pores under the hygrothermal coupling are analyzed in detail. The effect of porosity on wet heat conduction of thermoplastic polymeric materials was obtained. In addition to porosity, the effects of mechanical load, temperature and humidity load and thickness ratio on the mechanical properties of thermoplastic polymerized cylinder are discussed. The research work in this paper will enrich and develop composite materials, structural dynamics and thermoelastic mechanics. At the same time, the conclusions obtained in this paper provide a certain theoretical basis for the manufacture and further study of thermoplastic polymeric materials, and have a certain practical application value in engineering.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33
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1 郑兴华,高媛;等离子熔射成形件的孔隙率测定[J];机械工艺师;2001年02期
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