Loading Conditions in Bolted and Riveted Joints Affected by Plate Thickness Ratio

Abstract

Bolted and riveted connections are quite commonly encountered in various design problems. Many trials have been carried out recently to determine the stress distribution in bolted and riveted joints which is of extreme importance in the design of such joints. Effect of many parameters has been investigated, however effect of thickness ratio of the joint plates did not take too much attention. In this analytic work the effect of various plate thickness on the load and stress distribution in cylindrical bolted joints has been investigated using the finite element technique. Computed results show that the load as well as the stress or pressure distribution under bolt-head or nut are not constant nor uniform. Whatever the thickness ratio of the two plates (I1/L2), constant load and stress occurred across the joint under the bolt-head end. Maximum stress on surface and up to the mid plane level showed an increase with the thickness ratio. However the maximum stress on interface decreases with the thickness ratio to reach its lowest at L1/L2 = 1. End of loading on surface or at mid plane increases with the increase in thickness ratio, and tends to approach a constant value at L1/L2 equals 10 or more—on interface the opening position—represented by diameter of joint to bolt diameter D/d, reaches a maximum value of 3.5 then decreases rapidly to reach a constant value of about 2.5 for L1/L2 = 10 or more. Also the thickness of the plate (L1) has a pronounced effect on the opening position.