ABSTRACT
The test was performed with and without Belleville springs on the studs. The results are shown in Figure 18. In both cases, as deflection increased Goint sections moved together) the bolt preload decreased. However, the amount of load that is lost was greatly affected by the spring rate of the fastening system. Note that the studs alone became completely unloaded at 0.0095 in. (Bolt stretch at 4000 lb was only about 0.005 in. The reason it deflected 0.0095 in. to unload the studs is that there was a total of 0.0045 in. of movement between the fixture components and the hydraulic press that was used.) When Bellevilles were used, over 62% of the original preload still remained at 0.0095 in. deflection.
