A simple calculation method of the spring constant in bolted joints using tap bolts.

Abstract

In designing bolted joints, it is necessary to know the compressive spring constants for clamped parts more exactly. Up to now, simple calculation method to obtain the compressive spring constants for clamped parts have been suggested. However, they are mainly for bolted joints in which nuts and bolts are used. A simple calculation method to obtain compressive spring constants for bolted joints in which tap bolts are used, has not yet been satisfactorily established. In this paper, deformations of bolted joints, in which hollow cylinders are clamped to a base by a tap bolt, are analyzed using a three-dimensional theory of elasticity. Using the numerical results, the spring constants can be calculated .The effects of certain factors on the spring constants are thus examined. A simple calculation method to obtain the spring constant in a bolted joint using a tap bolt is thus derived. Furthermore, experiments are carried out in order to verify this simple calculation method.