摘要
伴随着汽车轻量化的大力发展，铝合金的使用量不断增加，胶铆复合连接作为一种新型连接方式应运而生。胶铆复合连接集合了胶接和铆接连接方式的优点，有着优异的连接性能和承载力。本文通过实验方法，对胶铆混合接头的力学性能进行了研究，主要研究内容如下： （1）介绍了胶接-拉铆单/双搭接接头从选择接头材料到接头制作完成的全流程和准静态拉伸实验的详细测定步骤和扫描电子显微镜的观测方法，通过对比六组单/双搭接的胶接、铆接和胶铆连接接头的载荷-位移曲线和力学性能参数（峰值载荷、强度和吸能），得出胶铆连接接头能在一定程度上增大胶层和铆钉失效试验力，增大了失效位移，有效延长接头的承载时间，较大地增加了承载的能量吸收。胶铆复合连接接头在胶粘剂失效后，铆接能继续发挥连接作用，防止接头因胶层失效而彻底破坏，有效地延长了接头的服役时间，增强了承载能力，提高了接头连接的安全性和可靠性。 （2）以双铆钉胶接-拉铆单/双搭接接头为研究对象，研究铆钉不同排列方式、胶层厚度和搭接方式对接头力学性能的影响规律。通过准静态拉伸破坏试验，测得其力学性能参数。单搭接双铆钉横/纵排列的接头失效模式均为胶层先发生内聚失效，铆钉之后发生拉拔失效，但是横排列的接头胶层失效载荷和失效强度均高于纵排列的接头。第二峰值载荷即铆钉失效载荷不受排列方式影响。双搭接双铆钉横/纵排列的接头失效模式为试件中间的铝合金板发生不规则断开。横排列接头失效载荷高于纵排列接头。胶层厚度对铆钉和铝合金板的失效载荷、失效强度以及失效模式均无影响。
（3）以胶接-拉铆单/双搭接接头为研究对象，通过在胶层区域设置不同形式的人工缺陷，模拟胶层制备过程中产生的胶层内部缺陷，研究其对胶铆接头搭接剪切力学性能的影响规律。以6061-T6铝合金为基底制备胶接-拉铆接头试件，考虑单、双搭接试件形式，胶层内部预先放置不同厚度、面积、形状、位置的聚四氟乙烯缺陷片，对固化后的接头进行准静态拉伸破坏试验，并采用宏观观测和扫描电镜分析胶层失效表面宏观和微观样貌，从而对胶层内部缺陷对其失效模式影响机理进行评价。
本文的试验研究结果可为胶铆连接接头在车身上的设计和应用提供参考。
关键词：复合连接；失效载荷；胶接；铆接
Study on mechanical properties and failure mechanism of
hybrid bond-riveted joints
Abstract
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With the development of automobile lightweight, the usage of aluminum alloy is increasing. The bond-riveted joint has the advantages of adhesive joint and rivet joint, and it has excellent performance and bearing capacity. In this paper, through the experimental method, the mechanical properties of the riveted hybrid joint are studied. The main research contents are as follows:
(1) The whole process from selecting materials to completion of joint fabrication, detailed steps of quasi-static tensile test method of single/double lap joints and observation methods of scanning electron microscope are introduced. Six groups of the load-displacement curves and mechanical properties (peak load, strength and energy absorption) of single/double adhesive joints, rivet joints and bond-riveted joints are compared. It can be concluded that hybrid bond-riveted joint can increase the failure test force of adhesive layer and rivet to a certain extent, increase the failure displacement, effectively extend the bearing time of joint, and greatly increase the energy absorption of bearing. After the failure of bond-riveted joint can continue to play the role of connection, prevent the joint from being completely destroyed due to the failure of adhesive layer, effectively extend the service time of the joint, enhance the bearing capacity, and improve the safety and reliability of the joint.
(2) Double rivets of single/double lap joints are taken as the research object to study the influence rule of different rivet arrangement, adhesive layer thickness and lap joint mode on the mechanical properties of the joint. Its mechanical properties are measured by quasi-static tensile failure test. The joint failure modes of single lap joint and double rivet in transverse/longitudinal arrangement are all that the adhesive layer has cohesive failure first, and then the rivets drawing failure occurs, but the f
ailure load and failure strength of the adhesive layer in transverse arrangement are higher than those in longitudinal arrangement. The second peak load, the rivet failure load is not affected by the arrangement. The joint failure mode of double lap joints with double rivets in transverse/longitudinal arrangement is irregular disconnection of aluminum alloy plate in the middle of the specimen. The failure load of horizontal joint is higher than that of vertical joint. The thickness of adhesive layer has no effect on the failure load, failure strength and failure mode of rivets and aluminum alloy plates.
(3) Different forms of artificial defects are introduced in adhesive layer of hybrid bond-riveted single and double lap joints, simulating defects in the adhesive layer during the manufacture process, to study the effect of local defect on the lap shear mechanical performance of hybrid joint. The bond-riveted single and double lap joints are manufactured with 6061-T6 aluminum alloy as the adherend, and the artificial defects using Teflon spacer with different
II
thicknesses, areas, shapes and locations are placed in the inner region of the adhesive layer before adhesive curing. Quasi-static tensile testing is then conducted on the ready-cured hybrid joint, and macroscopic observation and scanning electron microscopy are used to analyze the failure modes on the failure surface.
The experimental results of this paper can provide a reference for the design and application of bond-riveted joint on the body.
Key Words：Hybrid joint；Failure load；Adhesive joint；Rivet joint
目录
摘要............................................................................................................................. I Abstract ............................................................................................................................. II 1 绪论.. (1)
1.1 研究背景及意义 (1)
1.2 轻量化材料胶铆连接国内外研究综述 (2)
1.2.1 轻量化连接方式实验研究 (2)
1.2.2 轻量化连接方式仿真研究 (4)
1.2.3 轻量化连接接头缺陷影响研究 (5)
1.3 本文主要研究内容 (6)
1.4 本章小结 (7)
2 胶铆复合连接失效分析 (8)
2.1 胶接接头的失效形式 (8)
2.2 铆接接头的失效形式 (9)
2.3 胶层损伤失效准则 (9)声波识别
2.4 铆钉损伤失效准则 (12)
2.5 铝合金板损伤失效准则 (13)
2.6 本章小结 (14)
3 铝合金胶铆复合连接力学性能试验研究 (15)
3.1 试验材料 (15)
3.2 试件尺寸和试验设计 (16)
恶霉灵原药
3.3 力学性能测试和扫描电子显微镜观察 (18)基质稳搬运机器人
3.4 试验结果与分析 (20)
3.5 本章小结 (24)
4 铝合金胶铆复合连接力学性能影响因素分析 (25)
4.1 铆接试验方案设计 (25)
4.2 搭接方式和铆钉排列方式对接头力学性能的影响分析 (27)
4.3 胶层厚度对接头力学性能的影响分析 (30)
4.4 本章小结 (32)
5 胶层缺陷对铝合金胶铆复合连接力学性能影响 (34)
光纤环网5.1 缺陷设计方案 (34)
IV
pe附着力促进剂5.2 无缺陷单/双搭接胶铆连接接头力学性能分析 (35)
5.3 工艺缺陷对单/双搭接接头力学性能的影响分析 (36)
5.4 胶层失效表面宏观和微观分析 (39)
5.5 本章小结 (41)
结论 (43)
参考文献 (45)
攻读硕士学位期间发表学术论文情况 (48)
致谢 (49)
大连理工大学学位论文版权使用授权书 (50)
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