Determining the Normal Stiffness of Joint Faces

Abstract

The effect of load and types of finish on the stiffness of joints between machine surfaces has been investigated. An expression has been established between the normal load and the elastic stiffness of the joint. This expression has been verified experimentally. The relationship enables figures of merit (m) to be obtained for different surface conditions, different methods of machining, and different sizes of joints. A survey of industrial practice in the machining of joint surfaces has also been undertaken. This has provided a representative selection of machine finishes and enables quantitative figures to be quoted for typical joints.