Achieving a Selected Load Distribution in the Bolted Joint of a Cylinder Head of Highly Variable Stiffness and Contact Geometry

A preselected, non-uniform load distribution was obtained in a single-pass, load-controlled, bolt-up procedure. This was done by experimentally determining the elastic interaction coefficients. The coefficients were based on measurement of compressive load in the joint in the vicinity of the bolts being tightened. The elastic interaction coefficients were then used to predict what loads associated with the tightening of each bolt would be required to achieve a selected non-uniform load distribution in the joint. The procedure worked on a cylinder head of an overhead valve V-8 engine. The desired distribution of load was achieved with an average deviation of 4.7%. Most of the deviation is due to a single undesirable sensor/bolt pairing which, if eliminated, results in an average deviation of 2% and a maximum deviation of 10%.