A Study on Bearing Surface Pressure Distribution of Bolted Joints

Influences of Angular Deviation of Bearing Surface

Abstract

Bearing surfaces of bolted joints have a heavy role to ensure tightening performance. The pressure distribution on the bearing surfaces is considered to be an important subject relating directly to that role. In this study, concerning the bearing surfaces of M 10 hexagon head bolts and M10 hexagon head bolt with flange, detailed analyses are done by a finite element method to consider the pressure distribution. The main purpose of the analyses is to solve influences by inclination angle φ_p and concavity angle φ_c which are regarded as the basic quantities of the angular deviation of the bearing surface. The pressure distribution is highly sensitive to both angles.It is known that even 1°of φ_p gives too much bias to the distribution and in hexagon head bolt with flange φ_c selected properly has an effect to adjust its shape (e.g.an adjustment to make the distribution more uniform). Additionally, practlcal suggestions are presented about the bending moment caused by φ_p and the equlvalent diameter of frictional torque influenced by φ_c.