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为提高对铆接装配中铆钉成型过程的认识,通过有限元软件对沉头铆钉成型过程进行了数值模拟分析.详细介绍了铆接模型的建立过程和材料大变形的性能处理方法,并根据应力时间曲线对成型过程进行了阶段划分.结果表明,数值模拟方法可有效的用于铆接成型过程分析,为后续的铆接强度和疲劳的模拟分析奠定了基础. 相似文献
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通过改变钻头的常规磨削方法,来达到镗或铰达不到的目的,最终取得了良好效果,从而达到提高生产效率、缩短制造周期的目的。 相似文献
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An analysis of a model of the process of cold-driving a rivet is carried out with the primary aim of identifying the origin and magnitude of the resulting clamping force exerted by the rivet on the lapped sheets. The development of high hydrostatic pressure in the rivet shank in the first stages of the driving process, and its subsequent release as the rivet head is squashed, is the key to understanding the origin of the clamping force. The average clamping stress in the rivet shank is on the order of
, where
is the yield stress of the rivet. The model is used to explore the role of some riveting variables, including differing yield stresses in the rivet and sheet materials, strain hardening, and head size. 相似文献
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S. S. Shishkin 《Journal of Machinery Manufacture and Reliability》2010,39(1):43-46
A method for calculating the contact pressure in durable rivet bonds under the action of the force of the rivet and as a result
of unloading is presented. A formula determining the radius of the plastic zone in sheets is developed. The phenomenon of
reverse plastic deformations in a shank is described. The values of the residual stresses in the panels are calculated. 相似文献
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为满足工艺要求,在抽芯铆钉钉套局部退火过程中,需要对其部分环节进行冷却,对此本文提出了相应的冷却系统要求,根据要求制定了冷却系统设计方案,完成了泵的计算选型和水箱设计,制定了工作流程图,为抗拉型抽芯铆钉钉套局部退火设备冷却系统设计提供了参考。 相似文献
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钛合金铆钉在塑性成型过程中存在变形抗力大、变形不均匀等问题。在铆接过程中引入电流辅助铆接技术可有效提升钛合金铆钉的铆接质量,其原理为通过在铆接过程中施加电流,改善金属铆钉塑性,提高铆钉的可加工性。以TA2M航空用铆钉为研究对象,研究了6种电流密度水平下铆钉的温升过程与成型效果,并开展拉伸试验与疲劳试验研究铆接件的力学性能。研究发现,通电会在较短时间内产生显著的焦耳热效应,这对难变形的钛合金铆钉来说是一种有效的热软化手段;通电带来的铆钉软化效应极大降低了加工难度,改善了镦头的成型效果;当通以电流密度为26 A/mm2的电流时,压铆力降低了24.69%,且镦头直径增大了6.80%,高度降低了14.04%,更加接近标准所要求的尺寸;电流辅助铆接技术对钛合金板连接件静态拉伸强度的影响不显著,但可有效提升连接件的疲劳寿命。 相似文献
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Faisal Aman S. Hossein Cheraghi Krishna K. Krishnan Hamid Lankarani 《The International Journal of Advanced Manufacturing Technology》2013,67(1-4):545-562
Sheet metal parts are widely used in the assembly of aircraft. The most common method of joining sheet metal parts is through riveting. There are many parameters associated with a riveting process that affect the quality of rivets and the integrity of the final assembled product. This paper presents a study on the effect of some controllable process parameters in riveting (i.e., the sequence of riveting, distance between rivets (pitch), and gap between sheets) on the quality of riveted lap joints and the formed rivets. The study is performed on a one eight-inch nominal diameter flat head Tinner rivet and 0.064-in.-thick aluminum sheet. Finite element simulation is used as a means of modeling and analysis of the riveting process. Statistical design of experiment is employed to analyze the simulation data. A good combination of riveting process parameters is found which minimizes the residual stress in sheets and rivets, bulging and material growth in sheets, and which reduces the chances of postriveting clearance in a riveted lap joint. 相似文献
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A. P. Kuznetsov 《Russian Engineering Research》2017,37(3):171-179
The evolution of concepts of accuracy and attainable machining accuracy are considered. The physical aspects of accuracy are discussed. The changes in the level of precision since 1800 are outlined, with predictions of what is attainable in the future. The energy barrier to accuracy is analyzed for various cutting technologies. 相似文献