Givens

Bio: Givens is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 7 citations.

Estimation of fatigue strength enhancement for carburized and shot-peened gears

Abstract: An experimental formula has been proposed to estimate the bending fatigue strength of carburized gears from the hardness and the residual stress. The derivation of the formula is briefly reviewed, and the effectiveness of the formula is demonstrated in this article. The comparison with many test results for carburized and shot-peened gears verifies that the formula is effective for the approximate estimation of the fatigue strength. The formula quantitatively shows a way of enhancing fatigue strength, i.e., the increase of hardness and residual stress at the fillet. The strength is enhanced about 300 MPa by an appropriate shot peening, and it can be improved still more by the surface removal by electropolishing. 25 refs.

Simulation de l'usure et d'avaries sur des dentures d'engrenages cylindriques : Influence sur le comportement statique et dynamique de transmission par engrenages

Abstract: Les systemes de transmission par engrenages sont largement utilises pour transmettre de la puissance et adapter les vitesses de rotation entre organes moteurs et recepteurs. Dans ce contexte, les engrenages sont frequemment les organes parmi les plus sensibles de la chaine cinematique et peuvent etre soumis a un grand nombre d’avaries (fatigue de contact, fatigue de flexion, usure…etc.) apparaissant lors du fonctionnement et dont les causes sont multiples. L’objectif de ce travail est, d’une part, de simuler l’usure abrasive et la fatigue de contact conduisant a de l’ecaillage (pitting) et, d’autre part, d’analyser les interactions entre ces avaries et le comportement statique et dynamique de transmission par engrenages. A cette fin, un modele dynamique tridimensionnel d’engrenages de fortes largeurs est couple a des modeles d’usure et d’avaries de contact. L’usure est simulee en s’appuyant sur le modele d’Archard modifie afin de tenir compte de l’influence du regime de lubrification. Les usures obtenues apres un certain nombre de cycles de chargement sont considerees comme des ecarts initiaux additionnels par rapport a la geometrie ideale du flanc de denture. Les phenomenes de fatigue de contact par pitting sont analyses en deux etapes; a) une periode d’initiation de fissure simulee en s’appuyant sur plusieurs criteres de fatigue multiaxiaux et b) une phase de propagation de fissure traitee par la mecanique lineaire elastique de la rupture. Les sollicitations dynamiques fournies par le modele dynamique d’engrenages sont utilisees comme donnees d’entree pour la simulation des periodes d’initiation puis de propagation. Un grand nombre d’exemples d’application sont presentes et les interactions entre comportement dynamique, usure et fatigue sur des engrenages cylindriques sont analysees.

The Bending Strength of Carburized Fine Module Gear Teeth : Carburizing Conditions and Their Effects on the Fatigue Strength

Abstract: In this study, carburized gears of m=1.0-1.5 with various effective case depths are put to bending fatigue tests, and the fatigue strength is obtained. The test results verify that the effective case depth recommended in the AGMA standard is appropriate for the enhancement of bending strength. 0n the basis of results, S-N curves are determined and illustrated. The fatigue strength of the gears is about 1100 MPa. The fatigue strength is compared and illustrated with the strength of the gear teeth of m=5, and the effect of the tooth size on the fatigue strength is estimated quantitatively. The estimated size factor of the carburized gears is 1.0-1.3.

Bending fatigue testing of gear teeth under random loading

Abstract: The gears in a gear box fitted in an armoured tracked vehicle for the purpose of power transmission and positioning of rotating heavy mass to the desired angle with high accuracy are subjected to fluctuating loads that are random in nature. One of the important modes of failure in cyclic loading conditions including random loads is fatigue failure. It is thus important from the design point of view to estimate the life of the gears under these conditions. The fatigue life of components subjected to sinusoidal loading can be estimated by using cumulative damage theories. Their extension to random load fatigue, though straightforward, may not be very accurate owing to inherent scatter exhibited by the fatigue phenomenon. It is therefore necessary experimentally to determine the fatigue life of randomly loaded components and establish the validity of the theoretical model. An electrohydraulic test rig has been designed and fabricated that is capable of generating different types of load pattern by ad...

A Theoretical and Experimental Investigation on Bending Strength and Fatigue Life of Spiral Bevel and Hypoid Gears

Abstract: .................................................................................................................................... ii DEDICATION ................................................................................................................................ iv ACKNOWLEDGMENTS ............................................................................................................... v VITA ............................................................................................................................................... vi PUBLICATIONS ............................................................................................................................ vi FIELDS OF STUDY....................................................................................................................... vi TABLE OF CONTENTS ............................................................................................................... vii LIST OF TABLES .......................................................................................................................... xi LIST OF FIGURES ....................................................................................................................... xii NOMENCLATURE ...................................................................................................................... xx TOOTH NOMENCLATURE ...................................................................................................... xxv CHAPTER 1 1.1 Background and Motivation .................................................................................................... 1 1.2 Literature Review..................................................................................................................... 4 1.2.1 Gear Root Stresses Prediction Models ............................................................................... 4 1.2.2 Influence of Misalignments on Gear Bending Stresses ..................................................... 7 viii 1.2.3 Gear Bending Fatigue Models ........................................................................................... 8 1.3 Scope and Objectives ............................................................................................................. 11 1.4 Dissertation Outline ............................................................................................................... 13 CHAPTER 2 2.