Nonlinear Effects on the Stresses and Deformations of Bolted Joints

Abstract

Axisymmetric finite element modeling of bolted joints was performed to show the effects of the magnitude as well as the radial location of the externally applied load on the member separation radius and the stress on the surface between the two members. The separation radius was found to be nonlinearly related to changes in the magnitude as well as position of the external load. A 27-percent decrease for 24-mm bolts to 39-percent decrease for 8-mm bolts in the separation radius resulted with changes in the load magnitude. The external load varied from zero to the maximum that could be sustained before joint separation for steel members. The change in separation radius for the aluminum members, cast iron members, and a combination of the two materials was on the order of 2–10 percent. For the minimum and maximum external load, the separation radius decreased by 5 and 12 percent, respectively, with an increase in radial position of one to five bolt diameters for the 24-mm bolt models. Changes in the stress on the surface between the members also occurred with changes in magnitude as well as radial position of the external load. The stress was found to be higher near the bolt for larger external loads and also when the radial location of the external load was increased.