薄壳构件硬涂层阻尼减振机理分析模型的创建及模型应用研究

发布时间：2018-06-10 14:55

本文选题：薄壳构件 + 硬涂层阻尼　；参考：《东北大学》2015年硕士论文

【摘要】：由于硬涂层可在高温、高腐蚀环境下减少薄壳结构的振动响应,而受到越来越广泛的关注。为了更好的实施硬涂层阻尼减振,需要获得硬涂层的减振机理,即涂敷硬涂层后结构件振动响应减少的原因,进而实施硬涂层减振优化设计。现有的关于硬涂层减振机理的研究,多集中于微观材料学,且多数学者认为硬涂层微观颗粒之间的内摩擦是硬涂层能够减振的原因。但是,完全基于材料学研究的硬涂层减振机理是不够的,尚需要从宏观动力学的角度,创建硬涂层复合结构的动力学分析模型,进而研究硬涂层的减振机理。本文以涂敷硬涂层的梁、薄板以及薄圆柱壳为研究对象,在科学引入硬涂层材料力学特点的基础上,建立了硬涂层阻尼减振机理分析模型并且利用相关模型进行了应变能测试以及硬涂层参数影响分析等应用研究,具体研究内容体现在如下五方面:首先,从分离硬涂层的阻尼贡献出发,研究了创建硬涂层悬臂梁复合结构减振机理分析模型的方法。具体可描述为:对涂层前后的悬臂梁系统进行了减振特性实验,获得了固有频率、阻尼比、振动响应等参数;对涂层前后悬臂梁系统的储能及耗能进行分析,获取硬涂层材料的阻尼贡献;基于Oberst梁理论,创建了同时考虑材料阻尼和粘性阻尼的悬臂梁系统减振机理分析模型,并用实验校验了分析模型的正确性。其次,研究了创建硬涂层悬臂薄板复合结构减振机理分析模型的方法。建模过程如下:对涂层前后的悬臂薄板系统进行了减振特性实验,获得了固有频率、阻尼比、振动响应等参数;对涂层前后悬臂薄板系统储能及耗能分析的基础上,确定了获取硬涂层材料阻尼贡献的方法;基于拉格朗日方程,创建了同时考虑材料阻尼和粘性阻尼的悬臂薄板系统减振机理分析模型,并用实验校验了分析模型的正确性。然后,以涂层前后圆柱壳为对象,研究创建了硬涂层圆柱壳的减振减振机理分析模型。研究过程可描述为:进行振动测试实验,通过扫频激励和定频激励得到涂层前后圆柱壳的固有频率和共振响应,进而以幅频特性曲线,应用半功率带宽法得到涂层前后圆柱壳的模态阻尼比,基于Love薄壳理论,推导得到硬涂层圆柱壳的线性振动方程。利用能量法确定硬涂层圆柱壳的振动特征方程,基于Galerkin离散对硬涂层圆柱壳特征方程进行求解,确定硬涂层圆柱壳的固有频率;依据Obest理论引入涂层材料的损耗因子,采用梁函数组合法求解硬涂层的圆柱壳的共振响应;相关结果与实验比对,证明了所创建模型的合理性。接着,利用硬涂层悬臂梁减振机理分析模型,研究了间接测试硬涂层复合件应变能的方法。在对涂层前后悬臂梁系统应变能分析的基础上,确定了间接辨识涂层前后构件应变能的原理及方法,并提出了具体的辨识流程,包括:测试悬臂梁的共振位移响应;测试模态阻尼;利用模型修正技术与实验匹配;绘制梁共振状态的挠曲线;辨识应变能等步骤。利用涂敷NiCrA1Y前后的钛梁进行了实例研究,有效获取了应变能,并证明了该硬涂层对钛梁有减振效果。最后,利用所创建的硬涂层圆柱壳减振机理分析模型,分析了包括杨氏模量、损耗因子以及涂层厚度等硬涂层参数对圆柱壳振动特性的影响规律。结果表明:随着涂层杨氏模量、厚度的逐渐增加,涂层后的复合圆柱壳的固有频率有一定幅度的增大,共振响应逐渐减小;随着涂层的损耗因子的逐渐增加,硬涂层复合圆柱壳的共振响应逐渐越小,但是,对于硬涂层复合圆柱壳的固有频率没有影响。本文可为在硬涂层减振研究中,为进一步选择与制备硬涂层材料以及深入研究硬涂层的阻尼减振机理提供参考,也可为硬涂层减振技术在动力装备薄壳结构上推广应用提供支持。
[Abstract]:Because hard coating can reduce vibration response of thin shell structure under high temperature and high corrosion environment, it has received more and more attention. In order to better implement the damping of hard coating, it is necessary to obtain the vibration damping mechanism of hard coating, that is, the reason of reducing the vibration response of the hard coating after coating hard coating, and then implementing the optimization design of the hard coating. The research on the vibration damping mechanism of hard coating is mainly focused on micro material science, and many mathematicians think the internal friction between hard coating micro particles is the reason why hard coatings can reduce vibration. However, the vibration damping mechanism of hard coatings based on material studies is not enough. It is still necessary to create hard coating composite structures from the perspective of macro dynamics. In this paper, on the basis of the mechanical characteristics of hard coating materials, the analysis model of the damping mechanism of hard coating is established on the basis of the mechanical characteristics of hard coating materials, and the strain energy test and hard coating are carried out with the related model. The specific research content of the parameter influence analysis is embodied in the following five aspects: first, starting from the damping contribution of the hard coating, the method of establishing the analysis model of the vibration damping mechanism of the hard coating cantilever beam composite structure is studied. The concrete can be described as: the vibration damping characteristic experiment of the cantilever beam system before and after the coating has been carried out, and the inherent characteristics are obtained. Frequency, damping ratio, vibration response and other parameters, the energy storage and energy consumption of the cantilever beam system before and after coating are analyzed, and the damping contribution of hard coated materials is obtained. Based on the Oberst beam theory, an analysis model of the damping mechanism of cantilever beam system with material damping and viscous damping is created, and the correctness of the analysis model is verified by experiments. At the same time, the method of creating an analysis model for the vibration damping mechanism of a hard coated cantilever plate composite structure is studied. The modeling process is as follows: the vibration damping characteristics of the cantilever plate system before and after the coating are tested, and the parameters of natural frequency, damping ratio and vibration response are obtained. Based on the analysis of energy storage and energy consumption of the cantilever thin plate system before and after the coating, it is determined that A method for obtaining the damping contribution of hard coated materials is obtained. Based on the Lagrange equation, an analysis model of the vibration damping mechanism of a cantilever plate system with both material damping and viscous damping is created, and the correctness of the model is verified by experiments. Then, the damping and vibration reduction of a hard coated cylindrical shell is established by using the cylindrical shell before and after the coating as the image. The mechanism analysis model can be described as a vibration test experiment. The natural frequency and resonance response of the cylindrical shell before and after the coating are obtained through the sweep frequency excitation and the constant frequency excitation, and then the modulus damping ratio of the cylindrical shell before and after the coating is obtained by the amplitude frequency characteristic curve, and the hard coating is derived based on the Love thin shell theory. The linear vibration equation of the cylindrical shell is used to determine the vibration characteristic equation of the hard coated cylindrical shell. Based on the Galerkin dispersion, the characteristic equation of the hard coated cylindrical shell is solved, and the natural frequency of the hard coated cylindrical shell is determined. Based on the Obest theory, the loss factor of the coating material is introduced and the hard coating circle is solved by the array of beam functions. The resonance response of the cylindrical shell is compared with the experimental comparison, which proves the rationality of the model created. Then, the method of indirect testing the strain energy of hard coated composite parts is studied by using the analysis model of the vibration damping mechanism of hard coated cantilever beam. On the basis of the strain energy analysis of the cantilever beam system before and after the coating, the indirect identification of the front and rear structures of the coating is determined. The principle and method of the strain energy are introduced, and the specific identification process is presented, including testing the resonance displacement response of the cantilever beam, testing the modal damping, using the model correction technique to match the experiment, drawing the deflection curve of the beam resonance state, identifying the strain energy and so on. The application of the titanium beam before and after the application of NiCrA1Y has been effectively obtained. It is proved that the hard coating has a damping effect on the titanium beam. Finally, the influence rule of hard coating parameters, including young's modulus, loss factor and coating thickness, on the vibration characteristics of cylindrical shell is analyzed by using the analysis model of the vibration damping mechanism of the hard coated cylindrical shell. Adding, the natural frequency of the composite cylindrical shell increases to a certain extent, and the resonance response decreases gradually. With the gradual increase of the loss factor of the coating, the resonance response of the hard coated composite cylindrical shell is gradually smaller, but it has no effect on the natural frequency of the hard coated composite cylindrical shell. This paper can be used in the study of the vibration damping of hard coating. The further selection and preparation of hard coating materials, as well as the study of the damping mechanism of hard coatings, can also provide support for the application of hard coating vibration damping technology to the application of the thin shell structure of power equipment.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB30

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