NUMERICAL AND THEORETICAL STUDIES OF BOLTED JOINTS UNDER HARMONIC SHEAR DISPLACEMENT

Abstract

A THREE-DIMENSIONAL FINITE ELEMENT MODEL USED TO SIMULATE THE BOLTED JOINT IS CREATED USING ABAQUS PACKAGE. THE STRESS CONCENTRATION FACTORS AT THE ROOTS OF THE THREAD ARE FIRST STUDIED WITH A PRELOAD OF 38.4 KN. UNDER HARMONIC TRANSVERSE SHEAR DISPLACEMENT, NOT ONLY THE STRESS VARIATIONS AT TEN SPECIFIED POINTS OF THE FIRST THREAD BUT ALSO CONTACT CONDITIONS BETWEEN THE CONTACTING SURFACES ARE STUDIED. BY CHANGING THE PRELOAD VALUE, RELATIVE DISPLACEMENT, THE COEFFICIENT OF FRICTION BETWEEN THE TWO CLAMPED PLATES SUCCESSIVELY AND THE LOADING FREQUENCY, THEIR EFFECTS ON THE HYSTERESIS LOOPS OF THE TRANSVERSE LOAD VERSUS THE RELATIVE DISPLACEMENT OF THE JOINT ARE THEN ANALYZED. FINALLY THE HYSTERESIS LOOPS ARE PRODUCED BY THE MASING MODEL. IT IS FOUND THAT DUE TO THE GREATEST STRESS CONCENTRATION FACTOR, FATIGUE FAILURE WILL OCCUR AT THE ROOT OF THE FIRST THREAD. WITH THE INCREASE OF PRELOAD VALUE, THE AMPLITUDE OF DISPLACEMENT AND THE COEFFICIENT OF FRICTION, FRICTIONAL ENERGY DISSIPATION OF THE JOINT INCREASES. VERY GOOD AGREEMENT IS ACHIEVED BETWEEN THE HYSTERESIS LOOPS PRODUCED FROM THE FOURTH-ORDER MASING MODEL AND THE DETAILED ABAQUS MODEL AND THEREFORE THE FOURTH-ORDER MASING MODEL CAN REPLACE THE TIME-CONSUMING FINITE ELEMENT MODEL.