New Finite-Element Model of Thread Rolling

Abstract

This paper describes a three-dimensional finite-element analysis of thread rolling of a 12-point flange bolt using a rigid-plastic finite-element method. The paper also presents a new analysis model for simulating the thread rolling of fasteners or bolts. The new analysis model is characterized by a slice of material and two artificial symmetric planes and is based on negligible change in the longitudinal dimension of the material during thread rolling. The approach was applied to simulating the thread rolling of a flange bolt with a relatively small pitch and depth, and the predictions were compared to experimental results. The deformation of the concave crest at the top of the thread was observed during the final stage of thread rolling, and the predicted thread shape lines agreed closely with the experimental results. However, the effective strain distribution was not reliable because of excessive remeshing, which was inevitable due to the intrinsic geometric complexity of the thread rolling of bolts.