Investigation into the Effect of the Nut Thread Cutting on the Stress Distribution in a Bolt Using the Finite Element Method

Abstract

In order to abate fatigue fracture at roots of the first or the second hackle thread of bolt used for hydraulic press ,law of stress and load distribution in bolt threads suffered the axial forces were researched by using nonlinear finite element method.It was found that Peak equivalent stress in roots near axial force are abviously greater than these far away axial force when nut threads are in elastic range,but almost are equial to stress in roots far away axial force when 70% nut threads are in plastic region.Nut thread cutting to the fisrt two teeth can improve stress distribution in a bolt ,but these improvement recede quickly as plastic rigions of nut threads extend.