Consideration of Moving Tooth Load in Gear Crack Propagation Predictions
Title | Consideration of Moving Tooth Load in Gear Crack Propagation Predictions PDF eBook |
Author | |
Publisher | |
Pages | 16 |
Release | 2000 |
Genre | |
ISBN |
Robust gear designs consider not only crack initiation, but crack propagation trajectories for a fail-safe design. In actual gear operation, the magnitude as well as the position of the force changes as the gear rotates through the mesh. A study to determine the effect of moving gear tooth load on crack propagation predictions was performed. Two dimensional analysis of an involuted spur gear and three-dimensional analysis of a spiral-bevel pinion gear using the finite element method and boundary element method were studied and compared to experiments. A modified theory for predicting gear crack propagation paths based on the criteria of Erdogan and Sih was investigated. Crack simulation based on calculated stress intensity factors and mixed mode crack angle prediction techniques using a simple static analysis in which the tooth load was located at the highest point of single tooth contact was validated. For three-dimensional analysis, however, the analysis was valid only as long as the crack did not approach the contact region on the tooth.
Gear Crack Propagation Path Studies: Guidelines for Ultra-Safe Design
Title | Gear Crack Propagation Path Studies: Guidelines for Ultra-Safe Design PDF eBook |
Author | |
Publisher | |
Pages | 18 |
Release | 2001 |
Genre | |
ISBN |
Design guidelines have been established to prevent catastrophic rim fracture failure modes when considering gear tooth bending fatigue. Analysis was performed using the finite element method with principles of linear elastic fracture mechanics. Crack propagation paths were predicted for a variety of gear tooth and rim configurations. The effects of rim and web thicknesses, initial crack locations, and gear tooth geometry factors such as diametral pitch, number of teeth, pitch radius, and tooth pressure angle were considered. Design maps of tooth/rim fracture modes including effects of gear geometry, applied load, crack size, and material properties were developed. The occurrence of rim fractures significantly increased as the backup ratio (rim thickness divided by tooth height) decreased. The occurrence of rim fractures also increased as the initial crack location was moved down the root of the tooth. Increased rim and web compliance increased the occurrence of rim fractures. For gears with constant pitch radii, coarser-pitch teeth increased the occurrence of tooth fractures over rim fractures. Also, 250 pressure angle teeth had an increased occurrence of tooth fractures over rim fractures when compared to 200 pressure angle teeth. For gears with constant number of teeth or gears with constant diametral pitch, varying size had little or no effect on crack propagation paths.
Research & Technology 2001
Title | Research & Technology 2001 PDF eBook |
Author | |
Publisher | DIANE Publishing |
Pages | 251 |
Release | |
Genre | |
ISBN | 1428918213 |
Journal of Mechanical Design
Title | Journal of Mechanical Design PDF eBook |
Author | |
Publisher | |
Pages | 818 |
Release | 2008 |
Genre | Engineering design |
ISBN |
Research and Technology 2001
Title | Research and Technology 2001 PDF eBook |
Author | |
Publisher | |
Pages | 250 |
Release | 2002 |
Genre | |
ISBN |
Journal of the American Helicopter Society
Title | Journal of the American Helicopter Society PDF eBook |
Author | American Helicopter Society |
Publisher | |
Pages | 316 |
Release | 2002 |
Genre | Helicopters |
ISBN |
Experimental and Computational Methods for Strength Analyses of Gears
Title | Experimental and Computational Methods for Strength Analyses of Gears PDF eBook |
Author | Srečko Glodež |
Publisher | Cambridge Scholars Publishing |
Pages | 173 |
Release | 2024-01-24 |
Genre | Technology & Engineering |
ISBN | 1527575632 |
Gears are machine elements used in most engineering applications, mainly in the automotive and aerospace industries. When designing gear drives, the available standardised procedures are usually used for that purpose. However, the available computational methods are also often applied to obtain the load capacity of gears considering different fatigue design approaches (i.e. the stress-life approach, the strain-life approach and the fatigue crack growth approach). This book consists of five chapters. The first chapter introduces the reader to the fundamental magnitudes of gear drives concerning cylindrical gear pairs, bevel gear pairs, and worm gear pairs. The second chapter explains the theoretical background of the load capacity of gears; surface pitting load capacity and tooth root load capacity are described in detail. The third chapter focuses on the strength analyses of metal gears. Chapters four and five describe the strength analyses of sintered and polymer gears, including some typical practical examples.