机械固定结合面动态特性及建模研究

发布时间：2018-06-16 06:39

本文选题：螺栓固定结合面 + 动态特性　；参考：《哈尔滨工业大学》2012年硕士论文

【摘要】：螺栓固定联接是机械结构中最为普遍的一种零件联接方式，其联接面处的非线性特性是影响整体结构动态特性的主要因素。在现代机械高速化、高精度化及轻质化的趋势下，机械设计逐渐由静态设计转向动态设计，分析所设计结构的动态特性是动态设计的关键。因此，研究螺栓固定结合面的动态特性对结构设计及其优化具有极为重要的意义。本文从宏观角度分析了固定结合面的刚度和阻尼产生机理，建立了结合面的等效动力学模型；在微观方面建立了尺寸独立的分形结合面模型，通过MATLAB仿真得到结合面的法向和切向动态特性与面压力、表面粗糙度、真实接触面积等因素的关系。设计了考虑结合面影响因素权重的动态实验，建立了HT200、2Cr13材料在磨削和铣削条件下不同粗糙度的动态特性参数数据表；分析了螺栓预紧力、接触表面加工方式及表面粗糙度、不同接触面积对结合面动态特性的影响规律，验证了理论仿真结果的正确性。分别采用Glue粘接法、接触处理法和弹簧-阻尼单元等效法模拟了结合面的接触状况，比较了三种方法的优缺点及模拟精度；在研究了螺栓固定结合面的动态特性基础上，，提出了一种基于压力云图分布弹簧-阻尼单元的结合面建模方法；对HT200试件模态实验结果曲线拟合，建立了单位面积法向和切向动态特性与面应力的指数拟合曲线，将拟合参数代入模型，利用ANSYS软件对基于压力云图分布弹簧-阻尼单元的模型仿真，与实验结果及传统模型对比，验证了本模型的精确性。
[Abstract]:Bolt fixed connection is the most common part connection in mechanical structure. The nonlinear characteristics of the joint surface are the main factors that affect the dynamic characteristics of the whole structure. Under the trend of high speed, high precision and light weight of modern machinery, mechanical design is gradually changing from static design to dynamic design. The key to dynamic design is to analyze the dynamic characteristics of the structure. Therefore, it is very important to study the dynamic characteristics of bolt fixed joints for structural design and optimization. In this paper, the mechanism of stiffness and damping of the fixed joint surface is analyzed from the macro angle, the equivalent dynamic model of the binding surface is established, and the fractal joint surface model with independent dimensions is established in the microscopic aspect. The relationship between the normal and tangential dynamic characteristics of the combined surface and the factors such as surface pressure, surface roughness, real contact area and so on is obtained by MATLAB simulation. In this paper, the dynamic experiment considering the weight of the influence factors on the bonding surface is designed, and the data table of dynamic characteristic parameters of different roughness under grinding and milling conditions is established, and the pre-tightening force of bolt, the processing method of contact surface and the surface roughness are analyzed. The effect of different contact areas on the dynamic characteristics of the bonding surface is verified by the theoretical simulation results. Glue bonding method, contact treatment method and spring-damping element equivalent method are used to simulate the contact status of the joints, and the advantages, disadvantages and simulation accuracy of the three methods are compared. In this paper, a modeling method of joint surface based on pressure cloud image distribution spring damping element is proposed, and the exponential fitting curves of normal and tangential dynamic characteristics and plane stress of unit area are established by fitting the experimental results of HT200 specimen. The fitting parameters are substituted into the model, and the model based on the pressure cloud image distribution spring and damping element is simulated by ANSYS software. Compared with the experimental results and the traditional model, the accuracy of the model is verified.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH131

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