Clamp Load Loss due to Elastic Interaction and Gasket Creep Relaxation in Bolted Joints
Clamp Load Loss due to Elastic Interaction and Gasket Creep Relaxation in Bolted Joints
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DOI：
10.1115/1.2218343
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发表时间：
2006-08
影响因子：
1
通讯作者：
S. Nassar;Ali A. Alkelani
中科院分区：
文献类型：
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作者：
S. Nassar;Ali A. Alkelani
提出了一项实验研究，以确定螺栓接头中由于弹性相互作用和垫片蠕变松弛而导致的夹紧载荷损失。研究的参数包括垫片材料和厚度、螺栓间距、拧紧顺序、紧固件夹紧长度和紧固件预紧力水平。该接头由两个钢制法兰和丁苯橡胶或柔性石墨制成的垫片组成。法兰使用 M12x1.75 10.9 级紧固件紧固在一起。强力垫圈用于实时监控螺栓张力。考虑四种不同厚度的苯乙烯丁二烯橡胶垫片（1/16、1/8、3/16 和 1/4 英寸）和两种厚度的柔性石墨（1/16 和 1/8 英寸）。对于法兰的同一螺栓圆，通过使用不同数量的螺栓来改变螺栓间距；本研究考虑了与使用三个、五个或七个螺栓相对应的间距。通过使用顺序、星形或同时紧缩模式来研究紧缩策略的效果。螺栓紧固是通过使用具有各种控制选项的电动数字扭矩扳手或使用能够同时紧固所有紧固件的生产尺寸的多轴紧固系统来完成的。给出并分析了实验数据，以研究由于室温下弹性相互作用和垫片蠕变松弛的综合作用，各种参数对夹具负载损失的影响。
An experimental study is presented in order to determine the clamp load loss due to elastic interaction and gasket creep relaxation in bolted joints. Studied parameters include the gasket material and thickness, bolt spacing, tightening sequence, fastener grip length, and level of the fastener preload. The joint is composed of two steel flanges and a gasket made of styrene butadiene rubber or flexible graphite. The flanges are fastened together using M12x1.75 Class 10.9 fasteners. Force washers are used to monitor bolt tensions in real time. Four different gasket thicknesses of styrene butadiene rubber (1/16, 1/8, 3/16, and 1/4 in.) and two thicknesses of flexible graphite (1/16 and 1/8 in.) are considered. For the same bolt circle of the flange, the bolt spacing is varied by using a different number of bolts; spacing that corresponds to using three, five, or seven bolts is considered in this study. The effect of the tightening strategy is studied by using sequential, star, or simultaneous tightening patterns. Bolt tightening is accomplished by using either an electric digital torque wrench with various control options or by using a production-size multiple spindle fastening system that is capable of simultaneous tightening ofall fasteners. Experimental data is presented and analyzed, in order to study the effect of the various parameters on the clamp load loss due to the combined effect of elastic interaction and gasket creep relaxation at room temperature.