单搭接件力学性能研究

发布时间：2018-01-06 00:28

本文关键词：单搭接件力学性能研究　出处：《浙江大学》2016年硕士论文　论文类型：学位论文

【摘要】：对于飞机装配来说,搭接接头是关键部位,大约有85%的破坏都发生在铆接和螺栓连接等机械连接部位。在搭接接头的多排铆钉结构中,每个铆钉的承载比例存在差异,从干涉量的角度对单搭接件钉传载荷均化问题进行系统研究,在均化钉传载荷的基础上,使通过干涉量优化搭接件危险区域应力和提高搭接件承载能力成为可能。针对搭接件力学性能优化问题,本文进行了如下研究工作。首先,分析了铆接过程,对铆接后孔周残余应力简化计算公式进行了研究,为之后仿真结果提供对比,进一步研究了内外侧板件不同的孔扩张量对搭接件变形的影响。其次,分析了载荷从一个板件通过铆钉传递给另一个板件的过程中,存在的传递方式和力的类型。借助铆钉柔度的概念理论研究了多钉搭接件承载时的各钉承载比例,在此基础上预测了搭接件受拉伸载荷时的危险区域。接着,设计了三个不同的优化方案:1)不同的下压量;2)相同的钉孔直径,不同的铆钉直径;3)相同的铆钉直径,不同的钉孔直径;通过ABAQUS建立搭接件模型,进行三个方案的铆接和拉伸过程仿真。最后,对不同下压量组进行了搭接件力学性能试验验证。本文的主要研究成果包括:(1)通过建立搭接件的有限元模型,对不同钉载均化设计方案进行了铆接和拉伸过程的有限元仿真。开展了不同下压量和配合间隙的铆接仿真结果分析,并总结了孔周残余应力分布随不同参数变化的规律。对不同下压量和配合间隙的拉伸仿真结果进行钉传载荷比例和应力分布分析,对比了不同优化方案的优劣。(2)不同下压量的组合进行了力学性能试验,在危险点和关键截面上贴应变进行实时应变监测。对采集的数据结果进行危险点应力应变情况和关键截面传力趋势分析,分析结果验证了仿真模型的正确与有效。(3)仿真和试验都证实了:首先对于铆钉而言,通过合理控制三个铆钉的下压量,能够实现单搭接件在受拉伸载荷时铆钉均匀的受载,有利于减小两端铆钉的最大应力,提高搭接件铆钉的承载能力。其次对于板件而言,通过合理控制三个铆钉的下压量,可以减小搭接件的内外侧板受拉伸载荷时危险区域的最大应力,最大程度地使搭接板内各截面应力分布趋于均匀,提高了单搭接件内外侧板的承载能力。(4)对于沉头孔三钉单搭接件而言,三个铆钉最合适的下压量组合是:中间铆钉下压量比两侧铆钉的下压量大;固定端铆钉的下压量稍比另一端铆钉的下压量大。
[Abstract]:For aircraft assembly, the lap joint is the key part, about 85% of the damage occurred in the riveting and bolt connecting mechanical joints. Multi row rivet structure in lap joints, the bearing ratio of each rivet are different, both the problem of systematic study of single lap joint pin load from interference angle based on the homogenization, pin loads on the bearing capacity, improve lap joints made possible through interference optimization of dangerous area of lap joints stress and mechanical properties of joints. Aiming at the optimization problem, this paper carries out the following research work. Firstly, analyzed the process of riveting, riveting of residual stress after Kong Zhou formula is studied, the simulation results provide for comparison, further study of the inner and outer side hole expansion of lap joints deformation. Secondly, analyzes the load from a plate with rivets Transfer to another plate, the transmission and the type of existence. The concept of using the theory of rivet flexibility on the nail joints when loading the pin load distribution, based on the prediction of lap joints under tension load when the danger zone. Then, we design three different optimization solution: 1) under different pressure volume; 2) nail holes of the same diameter, different diameter of rivet; 3) the same diameter of rivet, screw holes of different diameters; establish lap joints model through ABAQUS simulation, riveting and tensile process of three schemes. Finally, under the pressure of different weight groups were the mechanical properties of lap joints test. The main achievements of this paper include: (1) by establishing a finite element model of lap joints, different pin load equalization scheme is analyzed by finite element simulation. The riveting and stretching process was carried out and the clearance of riveting pressure under different The analysis of simulation results, and summarizes the Kong Zhou residual stress distribution changes with different parameters. Simulation on tensile compression and clearance results under different of pin load ratio and stress distribution analysis, comparison of different optimization schemes. (2) the mechanical properties of test group was different under pressure together, with strain in the dangerous point and the key section of real-time monitoring of dangerous points. The strain analysis of stress and strain and force transmission of key sections trend of collected data results, analysis results validate the simulation model is correct and effective. (3) simulation and experiment have confirmed: first for rivets, through reasonable control of the three Rivet Press amount, can achieve single lap joints under tensile load when the rivet uniform loading, is conducive to the maximum stress decreases at both ends of a rivet, improve the bearing capacity of joints. Secondly for the plate rivet Three, through the reasonable control of the rivet press amount, can reduce the inner and outer side of lap joints under tensile load when the dangerous area of maximum stress, maximum makes each section plate internal stress distribution tends to be uniform, improve the bearing capacity of the single lap joints of inner and outer side. (4) for countersunk hole three nail single lap joints, three rivets the most suitable load combination is: intermediate Rivet Press amount than the two rivets under the pressure of large amount; slightly more than the other end of the rivet is under the pressure of large amount of pressure volume fixed end of the rivet.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V262.4;V215

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