EVALUATION OF THE STRESS CONCENTRATION ON TUBES WITH

EVALUATION OF THE STRESS CONCENTRATION ON TUBES WITH TRANSVERSAL HOLE BY MEANS OF THE FINITE ELEMENT METHOD Author: Ben Jordan Baxter Director: Juan José Ródenas García July 2016

INDEX • Summary and geometrical model • Mesh generation • Boundary conditions • Results • Macro • FEM and Peterson discrepancy • Polynomial Fitting • Conclusions

SUMMARY AND GEOMETRICAL MODEL MAIN GOAL Study stress concentration factor evolution and obtain an equation that represents this phenomenon, regardless geometry and forces ESSENTIAL PARAMETERS DEFINING GEOMETRICAL FEATURES: D, d/D, di/D

MESH GENERATION ACADEMIC ANSYS VERSION: 32000 NODE LIMITATION

BOUNDARY CONDITIONS THREE LOAD CASES AXIAL FORCE BENDING MOMENT TORSIONAL MOMENT EMBEDMENT AND USE OF A RIGID REGION FOR LOAD APPLYING

RESULTS

RESULTS VERIFY STRESS DISTRIBUTION IS CORRECT AND MAXIMUM STRESS IS AT HOLE

MACRO 64 POSSIBLE ANALYSES PROCESS AUTOMATION HOW TO CALL MACRO ? THREE LOAD CASES WITH THREE DIFFERENT CRITERIONS SOLVETUBE, D, d/D, di/D AUTOMATIC DATA SAVING SEPARATED IN FILES 576 RESULTS

FEM AND PETERSON DISCREPANCY AXIAL FORCE 1 ST PRINCIPLE STRESS 8 7 Kt 6 di/D = 0. 9 5 di/D = 0. 8 di/D = 0. 6 4 3 2 0 0. 1 0. 2 0. 3 0. 4 d/D 0. 5 SAME TENDENCY BUT SLIGHT DIFFERENCES. WHY? 0. 6 0. 7 0. 8

FEM AND PETERSON DISCREPANCY MAX STRESS LOCATION CHANGES WITH GEOMETRY MAXIMUM STRESS ISN`T ALWAYS AT EXTERIOR LAYERS PETERSON USED STRAIN GAGES ON EXTERIOR LAYERS EXPECTING MAX STRESS TO ALWAYS BE AT THIS LOCATION FEM PROVED PETERSON`S METHOD ISN`T TOTALLY CORRECT

POLYNOMIAL FITTING FIT RESULTS TO A COMPLETE THIRD DEGREE POLYNOMIAL HOW ? MATLAB LEAST SQUARE METHOD STRESS CONCENTRATION FACTOR FUNCTION OF d/D AND di/D RESULTS FOR AXIAL FORCE

CONCLUSIONS PROVES FINITE ELEMENT METHOD AS A POWERFUL CALCULUS TOOL AGAINST PETERSON`S EXPERIMENTAL METHODS