螺栓连接结构能耗机理及预示研究

发布时间：2018-04-15 02:19

本文选题：螺栓连接 + 搭接　；参考：《北京理工大学》2016年博士论文

【摘要】：螺栓连接结构所受到的切向载荷会引起组件结合界面的水平滑移,进而产生显著的能量耗散。针对连接结构的能量损耗机理开展研究,充分理解连接阻尼的影响因素,对于有效利用连接来降低结构振动响应,增强结构的寿命和可靠性具有重要的意义。对连接结构能量耗散机制研究的进一步的目标是实现连接阻尼的预示,逐渐摆脱对整机试验的依赖,加速产品的研发进程并降低产品的研发成本。本文采用理论数值研究和试验相结合的方法,对搭接连接能耗机理和连接结构阻尼预示进行了系统研究,主要研究内容如下:建立了适用于研究螺栓搭接连接微滑的一维连续体模型,计算得到了模型的微滑响应。分别从黏着-滑移转换、界面应力分布、载荷-位移曲线以及周期能耗等方面详细阐述了不同的界面特性和压力分布形式对螺栓搭接连接微滑及能量损耗的影响。建立了螺栓搭接连接的有限元模型,并详细描述了模型中需要识别的参数。利用响应面法和遗传算法,以试验获得的载荷-位移曲线结果为基准,识别出了有限元模型中的不确定参数。利用含有所识别参数数值的有限元模型,对不同预紧力和载荷作用下的螺栓连接的能量损耗规律进行了计算研究。建立了基于接触分析的螺栓连接结构的有限元模型并对其进行了模态分析计算。将模态振型相关的位移场施加在有限元模型上,计算得到了各阶摩擦能耗和模态阻尼,并将试验和仿真的结果进行了对比分析。借助于所搭建的哑铃式搭接连接试验台,通过测试得到了模拟界面的薄层单元的刚度和阻尼参数。将其应用于螺栓连接组合结构,利用应变能法得到了结构的各阶模态阻尼,并与试验结果进行了对比。提出一种基于非线性材料薄层单元的螺栓连接结构动力学预示方法。以非线性材料的本构模型为基础,根据孤立搭接连接的载荷-位移关系识别了材料参数,对一个含有搭接连接的结构进行了动力学试验和数值计算,进一步验证了结构的非线性特性以及预示仿真的可靠性。
[Abstract]:The tangential load on the bolted structure will lead to horizontal slip of the interface of the assembly, which will result in significant energy dissipation.It is of great significance to study the energy loss mechanism of the connection structure and fully understand the influencing factors of the connection damping, which is of great significance for the effective use of the connection to reduce the vibration response of the structure and to enhance the life and reliability of the structure.The further goal of the study on energy dissipation mechanism of connection structure is to realize the prediction of connection damping, gradually get rid of the dependence on the whole machine test, accelerate the process of product development and reduce the cost of product research and development.In this paper, the energy consumption mechanism and the damping prediction of the connection structure are systematically studied by combining the theoretical numerical research with the experimental method.The main research contents are as follows: a one-dimensional continuum model suitable for the study of micro-slip of bolt lap joint is established, and the micro-slip response of the model is calculated.The effects of different interface characteristics and pressure distribution on the micro-slip and energy loss of bolt lap joint are discussed in detail from the aspects of adhesion and slip conversion, interfacial stress distribution, load-displacement curve and periodic energy consumption.The finite element model of bolt lap connection is established, and the parameters to be identified in the model are described in detail.Based on the response surface method and genetic algorithm, the uncertain parameters in the finite element model are identified based on the load-displacement curve obtained from the experiment.Based on the finite element model with identified parameters, the energy loss law of bolted joints under different pretightening forces and loads is calculated and studied.The finite element model of bolted connection structure based on contact analysis was established and the modal analysis was carried out.The displacement field related to modal mode is applied to the finite element model and the friction energy consumption and modal damping of each order are calculated. The results of experiment and simulation are compared and analyzed.The stiffness and damping parameters of the thin layer element of the simulated interface are obtained by means of the dumbbell type lap joint test rig.This method is applied to bolted composite structure, and the damping modes of the structure are obtained by strain energy method, and the results are compared with the experimental results.A dynamic prediction method of bolted connection structure based on nonlinear material thin-layer element is proposed.Based on the constitutive model of nonlinear materials, the material parameters are identified according to the load-displacement relationship of isolated lap joints, and the dynamic tests and numerical calculations of a structure with lap connections are carried out.The nonlinear characteristics of the structure and the reliability of the prediction simulation are further verified.
【学位授予单位】：北京理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TH131.3

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