This study investigates the effect of shot-peened additively manufactured aluminum parts on the torque-tension relationship of threaded joints, as compared to extruded components. Steel flange head bolts are utilized. A computer-controlled RS torque-tension system is used for tightening test joints to a target preload, and frictional data is collected at a high sampling rate. A final group of additive manufactured specimens is analyzed to evaluate the effect of machining on the tribological response of the bolted joint. The underhead friction coefficient is measured over 5 consecutive tightenings, with and without disassembly and cooldown. The bearing surface topology is analyzed using an optical profilometer after each tightening. Fasteners and parts are ultrasonically cleaned, and tests are performed with no lubrication. Cooldown between consecutive tightenings had a significant effect on the frictional characteristics of non-machined additively manufactured joints. The lower surface integrity of the 3D printed components resulted in severe damage to the bearing surface after 5 tightening operations. Discussion of the results and conclusions are provided.
Robusto F., Gerini-Romagnoli M., De Agostinis M., Lee J.H., Nassar S.A. (2022). EFFECT OF USING 3D PRINTED PARTS ON THE TORQUE-TENSION RELATIONSHIP OF THREADED JOINTS. American Society of Mechanical Engineers (ASME) [10.1115/IMECE2022-95614].
EFFECT OF USING 3D PRINTED PARTS ON THE TORQUE-TENSION RELATIONSHIP OF THREADED JOINTS
De Agostinis M.;
2022
Abstract
This study investigates the effect of shot-peened additively manufactured aluminum parts on the torque-tension relationship of threaded joints, as compared to extruded components. Steel flange head bolts are utilized. A computer-controlled RS torque-tension system is used for tightening test joints to a target preload, and frictional data is collected at a high sampling rate. A final group of additive manufactured specimens is analyzed to evaluate the effect of machining on the tribological response of the bolted joint. The underhead friction coefficient is measured over 5 consecutive tightenings, with and without disassembly and cooldown. The bearing surface topology is analyzed using an optical profilometer after each tightening. Fasteners and parts are ultrasonically cleaned, and tests are performed with no lubrication. Cooldown between consecutive tightenings had a significant effect on the frictional characteristics of non-machined additively manufactured joints. The lower surface integrity of the 3D printed components resulted in severe damage to the bearing surface after 5 tightening operations. Discussion of the results and conclusions are provided.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
