典型机械连接结构有限元建模与实验验证研究

发布时间：2018-05-06 09:04

本文选题：有限元 + 板　；参考：《南京理工大学》2012年硕士论文

【摘要】：本文以某重点课题为研究背景,采用理论分析、数值计算和实验测试相结合的方法,对典型机械连接结构的建模理论与方法进行探讨研究,主要内容包括： (1)对经典的结构模态分析理论进行对比分析,重点阐述粘性阻尼和结构阻尼系统的模态分析理论,在此基础上分析了焊接、螺接、铆接等典型连接的机械力学特性,以及在工程领域中对这些连接结构的处理经验,借助于ANSYS软件建立典型机械连接结构的有限元模型。焊接建模时分别采用整体建模(忽略焊缝)、MPC约束模拟焊接关系、实体单元处理焊接处三种方法；采用梁单元、实体单元以及耦合节点法模拟螺栓连接；采用梁单元、弹簧单元、以及刚性连接来模拟铆接。利用三种建模方法对上述三种连接方式连接的铝合金‘I’型、‘T’型、‘十’型板件结构的固有振动频率和振型进行了数值计算,通过对比分析,发现采用不同的模拟方法对焊接和螺栓连接结构的模态计算结果影响不明显,但对铆接的计算结果影响较明显。此外,还建立了‘T’型钢质悬臂梁和简支梁的有限元模型,研究了固支端螺栓连接和简支端销轴连接的不同模拟方法对结构模态计算结果的影响。 (2)根据模态分析和测试实验技术,结合实验室现有实验条件,建立了锤击法模态测试实验系统。利用该系统分别对不同连接结构的铝合金板结构和钢质梁结构进行了模态特性测试研究,每种工况同时进行三组测试,得出了所有试件在Z向的自由振动固有频率和振型,将测试结果的平均值与理论计算结果进行对比分析,对各种建模方法的准确程度进行了评估。 (3)通过选取修正参数、状态变量和约束条件,建立了基于设计参数修改的结构有限元修正模型,根据计算频率与测试频率之间的误差大小,对螺栓连接、铆接、简支、悬臂等结构有限元模型的设计参数进行了修正研究。本文取得的典型机械连接结构的建模处理研究成果对机械结构的精细化建模具有较好的借鉴作用。
[Abstract]:In this paper, the modeling theory and method of typical mechanical connection structure are studied by the method of theoretical analysis, numerical calculation and experimental test. The main contents are as follows: 1) comparing and analyzing the classical structural modal analysis theory, focusing on the modal analysis theory of viscous damping and structural damping system. On this basis, the mechanical and mechanical characteristics of typical joints such as welding, screw joint and riveting are analyzed. With the help of ANSYS software, the finite element model of the typical mechanical connection structure is established by means of the experience in the engineering field. In welding modeling, the whole modeling method is used (ignoring the welding seam MPC constraint to simulate the welding relationship, the solid unit handles the welding place three methods; the beam element, the solid element and the coupling node method are used to simulate the bolt connection; the beam element, the spring element, the coupling node method), And rigid connections to simulate riveting. By using three modeling methods, the natural vibration frequencies and vibration modes of the aluminum alloy I'- type TX '-type plate structure are numerically calculated, and the results are compared and analyzed. It is found that the influence of different simulation methods on the modal calculation results of welded and bolted structures is not obvious, but the effect on the results of riveting is more obvious. In addition, the finite element models of T'steel cantilever beam and simply supported beam are established, and the influence of different simulation methods on the modal calculation results is studied. (2) according to the modal analysis and test technology, combined with the existing experimental conditions in the laboratory, the experimental system of hammer impact modal testing is established. The modal characteristics of aluminum alloy plate structure and steel beam structure with different connection structures were tested by this system. Three groups of tests were carried out at the same time under each working condition, and the natural frequencies and modes of free vibration of all specimens in Z direction were obtained. The average value of the test results is compared with the theoretical results, and the accuracy of various modeling methods is evaluated. By selecting the modified parameters, state variables and constraint conditions, the finite element correction model of structure based on the modification of design parameters is established. According to the error between calculating frequency and testing frequency, bolted connection, riveting, simple support, etc. The design parameters of the finite element model of cantilever structure are studied. The results obtained in this paper can be used for reference in the fine modeling of mechanical structures.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH131

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