耦合仿生抗冲蚀的试验研究及其应力波传导机制与规律的模拟分析

发布时间：2018-06-13 15:43

本文选题：耦合仿生 + 试验优化设计　；参考：《吉林大学》2014年博士论文

【摘要】：在工业生产当中，磨损会对于工程/机械表面造成严重的损耗，材料的磨损失效已经成为三大失效方式（腐蚀，疲劳，磨损）之一。据不完全估计，约50%以上的机器零件失效是由于磨损引起的，其中冲蚀磨损在工程应用中导致的器件失效，损坏大约占磨损总数的8%。冲蚀磨损是指大量固体粒子以一定的速度和攻角对材料表面进行冲击，导致材料损耗失效的过程。其广泛存在于机械，冶金，能源，化工，航天等诸多工程领域。如何有效地减少冲蚀的研究由来已久，迄今仍然是广大科学工作者重要的研究方向。随着冲蚀磨损理论的不断发展，人们从改进被冲蚀表面和改进冲蚀环境入手，不断引入新方法，耐磨抗冲蚀磨损的研究在不断地进步。本文从仿生学的新视角出发，研究生物体表形态并将之付诸于仿生学的应用：设计了耦合仿生样件与模型，并采取试验研究和理论与数值模拟相结合的方式，研究其耐磨抗冲蚀机理，以求在前人研究的基础上，进一步发展和完善仿生工程学的理论基础。本文主要由耦合仿生样件在冲蚀试验机下的冲蚀磨损试验和应力波在固体中传播理论主导的数值模拟分析组成。首先以沙漠中生活的新疆岩蜥和变色沙蜥为生物模型，通过对其体表鳞片形态和皮肤组织结构的观察和研究，发现沙漠蜥蜴体表抗冲蚀的优良性能是其体表形态和皮肤结构与材质共同耦合作用的结果。通过合理归纳和简化，提取背部和头部鳞片形貌特征与其体表皮肤的“软”“硬”分层结构特征建立耦合仿生抗冲蚀模型。在冲蚀试验部分，制备了三种表面形态的“硬”质层并进一步加工成表面形态与分层结构的耦合仿生样件。使用试验优化方法编制试验方案，选用L9(34)正交表进行试验设计。考察了磨粒目数，冲蚀角度和菱形、圆形、方形凸包三种表面形态三个因素对冲蚀磨损的影响，每个因素取三个水平，采用正交多项式回归设计得到回归方程，并用极差分析法确定了主次因素和优水平。为研究沙漠蜥蜴体表鳞片宏观上构成的沟槽形态对耐磨抗冲蚀性能的影响，加工并且制备了沟槽形表面的仿生样件。考察沟槽与喷嘴夹角、沟槽间距和样件材质三个因素的三个水平，采用L9(34)正交表进行试验设计。数值模拟试验部分主要研究冲蚀磨粒撞击在仿生模型表面后对亚表层及深层的影响。运用有限元软件Abaqus的显式动力学分析对棱形凸包、方形凸包和圆形凸包三种表面形态的模型、三种表面形态与“软”“硬”双层结构耦合的仿生模型及“切割”出的三种耦合仿生模型单元进行数值模拟研究。引入应力波在固体中的传播理论，构建可以修改的单个粒子冲击耦合仿生单元的模型进行数值模拟计算，采用将应力波理论与数值模拟分析结合的手段研究耦合仿生模型抗冲蚀的原理。在此基础上进行试验优化设计对数值模拟结果进行分析，采用L49(3)正交表，编制“硬”层厚度、“软”层材料组成和界面粘结三个因素对仿生模型内部轴向正应力幅值影响的试验方案并做极差分析。论文共七个章：第一章,绪论。第二章,对沙漠蜥蜴背部鳞片和皮肤结构的生物学特征进行观察和提取，研究其抗冲蚀特性、建立耦合仿生模型。第三章,分别制备了三种表面凸包（圆形、方形和棱形）与表面沟槽形貌的仿生样件，采用试验优化设计方法设计试验方案，在冲蚀试验机下进行冲蚀磨损试验，对试验结果用极差法分析主次因素和优水平，并且得到了冲蚀失重与各个试验因素（表面形态、材质、冲蚀角度等）的回归方程。第四章,建立相应的被粒子冲击的耦合仿生模型及其单元体并进行数值计算和分析，用等效应力衡量模型的抗冲蚀能力。第五章,引入应力波在固体中传播理论，，阐述应力波的碰撞原理及在“软”“硬”双层结构中的传播机制，介绍应力波传播导致的三种材料破坏方式。第六章,建立了可修正的数值模型，并结合应力波理论分析了“软”“硬”层材料、模型厚度、界面粘结、表面塑性化、凸包形态等因素对应力波传导的影响，其结果直接关系到模型的抗冲蚀能力；在数值模拟的基础上进行试验优化设计，得出回归方程。第七章,结论和展望。
[Abstract]:In industrial production, wear will cause serious loss to the engineering / mechanical surface, and the wear failure of the material has become one of the three major failure modes (corrosion, fatigue, and wear). According to incomplete estimation, about 50% of the failure of the machine parts is caused by wear and tear, and the failure of the device caused by the erosion and wear in the engineering application is damaged. 8%. erosion wear, which accounts for the total number of wear and tear, refers to the process of failure of material loss due to the impact of a large number of solid particles at a certain speed and angle of attack on the material surface. It widely exists in many engineering fields, such as mechanical, metallurgical, energy, chemical, aerospace and so on. How to reduce erosion effectively has been a long history and is still a large number of subjects. With the continuous development of the theory of erosion and wear, people have introduced new methods to improve the erosion surface and improve the erosion environment. The research on wear resistance and erosion wear is progressing continuously. From the new perspective of bionics, this paper studies the form of biological surface and put it into bionics. The coupling bionic sample and model are designed, and the mechanism of abrasion resistance and erosion is studied by the combination of experimental research and theory and numerical simulation. In order to further develop and improve the theoretical foundation of biomimetic engineering on the basis of previous research.
This paper mainly consists of the erosion wear test of the coupled bionic sample under the erosion test machine and the numerical simulation analysis of the propagation theory of stress wave in the solid. First, the Xinjiang lizard and the chameleon lizard in the desert are used as the biological model. Through the observation and Research on the shape of the surface scales and skin skin tissue structure of the desert, the desert is found and the desert is found. The excellent performance of the lizard's body surface resistance to erosion is the result of the coupling of body surface morphology and skin structure and material. By rational induction and simplification, a coupled bionic anti erosion model is established by extracting the features of the scales of the back and head and the "soft" "hard" layered structure of the skin of the skin.
In the erosion test part, three kinds of "hard" layer of surface morphology were prepared and further processed into the coupling bionic sample of surface morphology and stratified structure. The test scheme was prepared by the test optimization method and the L9 (34) orthogonal table was selected for the test design. The grinding grain number, the erosion angle and the rhombic, circular and square convex hull were investigated. The influence of three factors on erosion and wear, each factor takes three levels, the regression equation is obtained by orthogonal polynomial regression design, and the main and secondary factors are determined by the method of extreme difference analysis. The influence of the groove shape on the wear resistance of the body surface scales of the desert lizard is studied, and the grooves are processed and prepared. A bionic sample on the shape surface. The three levels of three factors, including the angle between the groove and the nozzle, the spacing between the trenches and the material of the sample, are examined. The L9 (34) orthogonal table is used for the experimental design.
In the numerical simulation test, the impact of erosion particles on the subsurface and deep layer after the surface of the biomimetic model is mainly studied. Using the explicit dynamic analysis of the finite element software Abaqus, the three surface morphology models of the prismatic convex hull, the square convex hull and the circular convex hull, and the bionic bionics of the three surface morphology and the "soft" double double layer structure are coupled. The model and the "cut" three coupling bionic model units are numerically simulated. The propagation theory of the stress wave in the solid is introduced, and the model of the single particle impact coupling bionic unit can be modified to simulate the numerical simulation. The coupled biomimetic model is studied by combining the stress wave theory with the numerical simulation analysis. On this basis, the experimental optimization design is carried out for the analysis of the numerical simulation results. The L49 (3) orthogonal table is used to compile the test scheme of the "hard" layer thickness, the "soft" layer material composition and the interface bonding three factors on the axial positive stress amplitude in the bionic model and make the extreme difference analysis.
The thesis consists of seven chapters: Chapter 1, introduction. The second chapter, the biological characteristics of the scales and skin structures of the back of the desert lizard are observed and extracted. The anti erosion characteristics of the desert lizard are studied and the coupling bionic model is established. In the third chapter, three bionic samples of the surface convex hull (round, square and prismatic) and the surface groove are prepared respectively. The experiment scheme was designed by the chemical design method. The erosion test was carried out under the erosion test machine. The main and secondary factors and the optimal level were analyzed by the extreme difference method, and the regression equation of the erosion weightlessness and the various test factors (surface morphology, material, erosion angle, etc.) was obtained. The fourth chapter established the corresponding coupling biomimetic model with particle impact. In the fifth chapter, the theory of stress wave propagation in solid is introduced, the principle of stress wave collision and the propagation mechanism in "soft" "hard" double layer structure are introduced, and three kinds of material destruction methods caused by stress wave propagation are introduced. The sixth chapter is built. The modified numerical model is established, and the stress wave theory is used to analyze the "soft" and "hard" layer material, the influence of the model thickness, the interface bonding, the surface plasticity, the convex hull form on the force wave conduction, and the result is directly related to the anti erosion ability of the model, and on the basis of the numerical simulation, the experimental optimization design is carried out to get the regression. The equation. The seventh chapter, the conclusion and the prospect.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TH117.1

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