NON LINEAR FINITE ELEMENT ANALYSIS OF THE CONTACT, STRAIN AND STRESS STATES OF A BOLT - NUT - WASHER - COMPRESSED SHEET JOINT SYSTEM

Abstract

A non-linear finite element model with contact elements was developed to evaluate the contact state of a bolt - nut - washer - compressed sheet joint system. Applying the proper material law the non-linear behaviour of the members of the joint was studied in term of the clamping force. Based on the FE results the load distribution among the threads in contact and the real preload diagram of the system were evaluated. To produce the required clamping force at medium strength bolts it is advisable to use heat-treated washers instead of lower strength ones.