基于丝瓜微结构的超轻仿生结构设计与热、力学分析

发布时间：2018-11-24 08:33

【摘要】：面对复杂多样、千差万别的工程结构,要求工程材料既要具有高的强度与刚度,又要轻质、节省材料。自然界生物体结构是亿万年自然选择和生命进化的结果,具有优良的力学性能。仿生结构材料的设计理论就是通过研究生物体的宏观、微观特性,发现其优良结构的学科。本文的主要目的是通过剖析自然界丝瓜络的微结构特征,研究丝瓜络的仿生结构,设计出类似泡沫金属的一种新型多孔结构材料,进而标定其力学和导热性能。主要研究内容包括以下三大部分:·丝瓜络微结构研究。对丝瓜络结构的深入研究是进行仿生结构设计的基础,因此,本文首先对丝瓜络的宏观几何形貌进行了描述,指出丝瓜络主要宏观形貌可以看作双层开孔的泡沫结构,内层与外层之间通过沿径向互成120°的筋板连接;然后利用澳大利亚国立大学的扫描电镜和激光切割技术对丝瓜络纤维的微结构进行观测;进而对丝瓜络段试样进行压缩实验测定其各项力学参数(等效弹性模量约为8.79MPa),并利用曲线拟合方法给出了等效弹性模量与密度的解析公式。·基于丝瓜络微结构特征,采用蜂窝六边形对其孔隙进行简化,并利用三维软件—Pro/E设计出这种新型超轻仿生结构材料。利用3D打印技术以ABS-M30为原料制造出这种仿生结构,并对其进行压缩实验,测定等效弹性模量为166.9~180.59MPa。·运用Abaqus有限元软件,采用双层夹板三明治结构对以ABS-M30为材料参数的仿生结构进行准静态压缩及稳定性数值仿真。计算出其等效弹性模量为133.21MPa,一阶屈曲临界载荷为1064.8N。另外,本文也对仿生结构的热传导过程进行数值模拟,以纯铝为材料参数,计算出等效热传导系数为6.35W/(m·K)。
[Abstract]:In the face of complex and diverse engineering structures, engineering materials are required not only to have high strength and stiffness, but also to be lightweight and save materials. The structure of natural organisms is the result of natural selection and evolution of life for billions of years and has excellent mechanical properties. The design theory of bionic structural materials is to find out the fine structure of objects through the macroscopic and microscopic characteristics of graduate students. The main purpose of this paper is to study the bionic structure of luffa lucifera by analyzing the microstructural characteristics of natural loofah, and to design a new porous structure material similar to foam metal, and then to calibrate its mechanical and thermal conductivity. The main research contents include the following three parts: studies on the microstructures of loofah. The deep study on the structure of loofah is the basis of bionic structure design. Therefore, this paper firstly describes the macroscopic geometry of loofah, and points out that the main macroscopic morphology of loofah can be regarded as the foam structure with double holes. The inner layer and the outer layer are connected with each other by a stiffened plate 120 掳along the radial direction. Then the microstructure of luffa was observed by scanning electron microscope and laser cutting technique of Australian National University. Then the mechanical parameters (equivalent modulus of elasticity is about 8.79MPa) were measured by compression experiments. The analytical formulas of equivalent elastic modulus and density were given by means of curve fitting, based on the microstructural characteristics of loofah. The porosity of honeycomb hexagonal is simplified, and the new ultra-light bionic structure material is designed by using three-dimensional software Pro/E. The bionic structure was fabricated by using 3D printing technology using ABS-M30 as raw material, and its compression experiment was carried out. The equivalent modulus of elasticity was determined to be 166.9 ~ 180.59 MPa. Abaqus finite element software was used. The quasi-static compression and stability numerical simulation of bionic structure with ABS-M30 as material parameter was carried out by using sandwich structure with double layer splint. The equivalent elastic modulus is 133.21 MPA and the first order buckling critical load is 1064.8 N. In addition, the thermal conduction process of bionic structure is numerically simulated. Using pure aluminum as material parameter, the equivalent heat conduction coefficient is calculated to be 6.35W/ (m K).
【学位授予单位】：河南工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB12

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