ABSTRACT
Figure 11 is a diagram of the same joint with Belleville springs added. If two Bellevilles are used that have a total deflection of 0.040 in., then dL, increases from 0.006 to 0.046 in. If the same figure for R is used, then
0.003 3 --------- = -= 6.5% 0.005 + 0.001 + 0.040 46 (3b)
of the original load would be lost to relaxation. To lose as much load as was lost without spring relaxation, R would have to increase by 460% (0.014 in.). Using Bellevilles in this manner to improve retained preload is commonly known as "live loading'' the joint. Live loading is effective because most gaskets do unload after installation. Increasing the fastening system deflection (dL,) reduces the effect of this phenomenon. The ratio of total R to dL, simply becomes smaller.
