Análise numérica e experimental da região dos filetes de rosca em uniões aparafusadas

Abstract

Many structures and machines are built using bolt and nut joints in different fields like automotive industry, industrial equipment, construction and others. Bolt and nut joints are easier to assemble and disassemble than other types of joints, turning itself the most used fixer in the world. However, the usage of the bolt and nut joint requires some caution, mainly when it is used in responsibility joints like pressure vessels or oil and gas pipelines. The present study shows some considerations about this kind of joint and analyses the friction coefficient, the most important property on surfaces in contact, on the thread contact region between bolt and nuts assemblage when a controlled torque is applied. The friction coefficient of different materials was founded and a commercial finite element code was used to obtain the stress state during the force application on thread contact region. In the results, could be verified that the relation between torque coefficient and friction coefficient are linear and a great number of variables can interfere at the moment of test. The friction coefficient was used as a set parameter to finite element simulation and shows some tendency with stress state obtained. Also an adaptation to the torque test machine has been projected to test another sizes of bolts and nuts.