Rim Thickness Effects on Gear Crack Propagation Life

Analytical and experimental studies were performed to investigate the effect of gear rim thickness on crack propagation life. The FRANC (FRacture ANalysis Code) computer program was used to simulate crack propagation. The FRANC program used principles of linear elastic fracture mechanics, finite element modeling, and a unique re-meshing scheme to determine crack tip stress distributions, estimate stress intensity factors, and model crack propagation. Various fatigue crack growth models were used to estimate crack propagation life based on the calculated stress intensity factors. Experimental tests were performed in a gear fatigue rig to validate predicted crack propagation results. Test gears were installed with special crack propagation gages in the tooth fillet region to measure bending fatigue crack growth. Good correlation between predicted and measured crack growth was achieved when the fatigue crack closure concept was introduced into the analysis. As the gear rim thickness decreased, the compressive cyclic stress in the gear tooth fillet region increased. The retarded crack growth and increased the number of crack propagation cycles to failure.

[1]  J. Flašker,et al.  Stress intensity factor for cracked gear tooth , 1994 .

[2]  R. D. Henshell,et al.  CRACK TIP FINITE ELEMENTS ARE UNNECESSARY , 1975 .

[3]  Donald R. Houser,et al.  The Stress Intensity Factor and Stiffness for a Cracked Spur Gear Tooth , 1994 .

[4]  Jože Flašker,et al.  Crack propagation in tooth root with variable loading , 1993 .

[5]  M. Williams,et al.  On the Stress Distribution at the Base of a Stationary Crack , 1956 .

[6]  Gianni Nicoletto,et al.  Approximate stress intensity factors for cracked gear teeth , 1993 .

[7]  Jj Au,et al.  Correlation between fatigue crack growth rate and fatigue striation spacing in AISI 9310 (AMS 6265) steel , 1981 .

[8]  Steve Daniewicz Conception and development of improved analytical prediction models for fatigue induced tooth breakage due to cyclic bending in spur gear teeth , 1991 .

[9]  S. Chan,et al.  On the Finite Element Method in Linear Fracture Mechanics , 1970 .

[10]  Dennis P. Townsend,et al.  Surface fatigue life of carburized and hardened M50NiL and AISI 9310 spur gears and rolling-contact test bars , 1989 .

[11]  G. Deng,et al.  Strength Evalulation of Carburized Gear Teeth Based on Fracture Mechanics , 1991 .

[12]  F. Erdogan,et al.  On the Crack Extension in Plates Under Plane Loading and Transverse Shear , 1963 .

[13]  Carl Albrecht Transmission Design Using Finite Element Method Analysis Techniques , 1988 .

[14]  P D McFadden Analysis of the Vibration of the Input Bevel Pinion in RAN (Royal Australian Navy) Wessex Helicopter Main Rotor Gearbox WAK143 Prior to Failure. , 1985 .

[15]  Roberto Ballarini,et al.  Effect of Rim Thickness on Gear Crack Propagation Path. , 1997 .

[16]  Dennis P. Townsend,et al.  Surface fatigue life of M50NiL and AISI 9310 gears and rolling-contact bars , 1991 .

[17]  G. Barnes,et al.  Shot-peened gear failure due to operation in a misaligned condition , 1993 .

[18]  M. Savage,et al.  Computer modeling of rack-generated spur gears , 1985 .

[19]  Hiroshi Honda,et al.  An Analysis by Finite Element Techniques of the Effects of a Crack in the Gear Tooth Fillet and its Applicability to Evaluating Strength of the Flawed Gears , 1979 .

[20]  J. Flasker,et al.  The Comparative Analysis of Crack Propagation in the Gear Tooth , 1984 .

[21]  R. Barsoum On the use of isoparametric finite elements in linear fracture mechanics , 1976 .

[22]  Raymond J. Drago,et al.  Combined Effects of Rim Thickness and Pitch Diameter on Spur Gear Tooth Stresses , 1983 .

[23]  P. C. Paris,et al.  A Critical Analysis of Crack Propagation Laws , 1963 .

[24]  D. M. Tracey,et al.  Discussion of ‘on the use of isoparametric finite elements in linear fracture mechanics’ by R. S. Barsoum , 1977 .