Controlled Tightening Over the Yield Point of a Screw: Based on Taylor’s Series Expansions

Abstract

The technique presented here focuses on the probabilistic nature of the different variables necessary for the calculation of screwed joints. The technique is based on Taylor’s series expansions or Monte Carlo simulations of the utilization of a screw over its yield point. It is very useful for quality controllers and design engineers since it is able to predict, for instance, the minimum and maximum snug torques, permanent elongation, final torque and preload after tightening. Comparisons are made between the results found of Monte Carlo simulations, series expansions and the extreme-value method. It is suggested that the Monte Carlo method is the most appropriate.