Download or read book Simulating Fatigue Crack Growth in Spiral Bevel Pinion written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-11 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project investigates computational modeling of fatigue crack growth in spiral bevel gears. Current work is a continuation of the previous efforts made to use the Boundary Element Method (BEM) to simulate tooth-bending fatigue failure in spiral bevel gears. This report summarizes new results predicting crack trajectory and fatigue life for a spiral bevel pinion using the Finite Element Method (FEM). Predicting crack trajectories is important in determining the failure mode of a gear. Cracks propagating through the rim may result in catastrophic failure, whereas the gear may remain intact if one tooth fails and this may allow for early detection of failure. Being able to predict crack trajectories is insightful for the designer. However, predicting growth of three-dimensional arbitrary cracks is complicated due to the difficulty of creating three-dimensional models, the computing power required, and absence of closed- form solutions of the problem. Another focus of this project was performing three-dimensional contact analysis of a spiral bevel gear set incorporating cracks. These analyses were significant in determining the influence of change of tooth flexibility due to crack growth on the magnitude and location of contact loads. This is an important concern since change in contact loads might lead to differences in SIFs and therefore result in alteration of the crack trajectory. Contact analyses performed in this report showed the expected trend of decreasing tooth loads carried by the cracked tooth with increasing crack length. Decrease in tooth loads lead to differences between SIFs extracted from finite element contact analysis and finite element analysis with Hertz contact loads. This effect became more pronounced as the crack grew.Ural, Ani and Wawrzynek, Paul A. and Ingraffe, Anthony R.Glenn Research CenterCRACK PROPAGATION; SPIRAL BEVEL GEARS; FATIGUE LIFE; FINITE ELEMENT METHOD; BENDING FATIGUE; PARALLEL PROCESSING (COMPUTERS); COMPUTERIZED SIMULATION
Download or read book Simulating Fatigue Crack Growth in Spiral Bevel Pinion written by and published by . This book was released on 2003 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: New results for predicting crack trajectory and fatigue life for a spiral bevel pinion using the Finite Element Method (FEM) are reported. The predictions presented are based on linear elastic fracture mechanics combined with the FEM, incorporating plasticity induced fatigue crack closure and moving gear tooth loads. The analyses were carried out using a parallel FEM solver, which calculates stress intensity factors using equivalent domain J-integral method. Fatigue life predictions were made based on a modified Paris model incorporating crack closure. To obtain a more detailed understanding of the contact between a cracked pinion tooth in mesh with an uncracked gear tooth, three-dimensional contact analyses were performed on a spiral bevel gear set incorporating a crack. The goal in carrying out these analyses was to capture the redistribution of contact loads due to crack growth. Results of these analyses showed the expected trend of decreasing tooth loads carried by the cracked tooth with increasing crack length. It was also showed that this decrease in contact loads bad an impact on the stress intensity factor values and therefore would also affect the crack trajectory and fatigue life predictions.
Download or read book Simulating Fatigue Crack Growth in Spiral Bevel Gears written by and published by . This book was released on 2000 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The majority of helicopter transmission systems utilize spiral bevel gears to convert the horizontal power from the engine into vertical power for the rotor. Due to the cyclical loading on a gear's tooth, fatigue crack propagation can occur. In rotor craft applications, a crack's trajectory determines whether the gear failure will be benign or catastrophic for the aircraft. As a result, the capability to predict crack growth in gears is significant. A spiral bevel gear's complex shape requires a three dimensional model of the geometry and cracks. The boundary element method in conjunction with linear elastic fracture mechanics theories is used to predict arbitrarily shaped three dimensional fatigue crack trajectories in a spiral bevel pinion under moving load conditions. The predictions are validated by comparison to experimental results. The sensitivity of the predictions to variations in loading conditions and crack growth rate model parameters is explored. Critical areas that must be understood in greater detail prior to predicting more accurate crack trajectories and crack growth rates in three dimensions are identified.
Download or read book Simulating Fatigue Crack Growth in Spiral Bevel Pinion written by Ani Ural and published by . This book was released on 2003 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: New results for predicting crack trajectory and fatigue life for a spiral bevel pinion using the Finite Element Method (FEM) are reported. The predictions presented are based on linear elastic fracture mechanics combined with the FEM, incorporating plasticity induced fatigue crack closure and moving gear tooth loads. The analyses were carried out using a parallel FEM solver, which calculates stress intensity factors using equivalent domain J-integral method. Fatigue life predictions were made based on a modified Paris model incorporating crack closure. To obtain a more detailed understanding of the contact between a cracked pinion tooth in mesh with an uncracked gear tooth, three-dimensional contact analyses were performed on a spiral bevel gear set incorporating a crack. The goal in carrying out these analyses was to capture the redistribution of contact loads due to crack growth. Results of these analyses showed the expected trend of decreasing tooth loads carried by the cracked tooth with increasing crack length. It was also showed that this decrease in contact loads bad an impact on the stress intensity factor values and therefore would also affect the crack trajectory and fatigue life predictions.
Download or read book Simulating Fatigue Crack Growth in Spiral Bevel Gears written by Lisa Eron Spievak and published by . This book was released on 2000 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The majority of helicopter transmission systems utilize spiral bevel gears to convert the horizontal power from the engine into vertical power for the rotor. Due to the cyclical loading on a gear's tooth, fatigue crack propagation can occur. In rotor craft applications, a crack's trajectory determines whether the gear failure will be benign or catastrophic for the aircraft. As a result, the capability to predict crack growth in gears is significant. A spiral bevel gear's complex shape requires a three dimensional model of the geometry and cracks. The boundary element method in conjunction with linear elastic fracture mechanics theories is used to predict arbitrarily shaped three dimensional fatigue crack trajectories in a spiral bevel pinion under moving load conditions. The predictions are validated by comparison to experimental results. The sensitivity of the predictions to variations in loading conditions and crack growth rate model parameters is explored. Critical areas that must be understood in greater detail prior to predicting more accurate crack trajectories and crack growth rates in three dimensions are identified.
Download or read book Advanced Three dimensional Simulations and Cohesive Modeling of Fatigue Crack Growth written by Ani Ural and published by . This book was released on 2004 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gear Crack Propagation Path Studies Guidelines for Ultra Safe Design written by and published by . This book was released on 2001 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Computational Mechanics written by Zhenhan Yao and published by Springer Science & Business Media. This book was released on 2009-03-24 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Mechanics is the proceedings of the International Symposium on Computational Mechanics, ISCM 2007. This conference is the first of a series created by a group of prominent scholars from the Mainland of China, Hong Kong, Taiwan, and overseas Chinese, who are very active in the field. The book includes 22 full papers of plenary and semi-plenary lectures and approximately 150 one-page summaries.
Download or read book Consideration of Moving Tooth Load in Gear Crack Propagation Predictions written by and published by . This book was released on 2000 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Fundamentals of Enriched Finite Element Methods written by Alejandro M. Aragón and published by Elsevier. This book was released on 2023-11-09 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Enriched Finite Element Methods provides an overview of the different enriched finite element methods, detailed instruction on their use, and also looks at their real-world applications, recommending in what situations they’re best implemented. It starts with a concise background on the theory required to understand the underlying functioning principles behind enriched finite element methods before outlining detailed instruction on implementation of the techniques in standard displacement-based finite element codes. The strengths and weaknesses of each are discussed, as are computer implementation details, including a standalone generalized finite element package, written in Python. The applications of the methods to a range of scenarios, including multi-phase, fracture, multiscale, and immersed boundary (fictitious domain) problems are covered, and readers can find ready-to-use code, simulation videos, and other useful resources on the companion website to the book. Reviews various enriched finite element methods, providing pros, cons, and scenarios forbest use Provides step-by-step instruction on implementing these methods Covers the theory of general and enriched finite element methods
Download or read book Frattura ed Integrit Strutturale Annals 2014 written by Luca Susmel and published by Gruppo Italiano Frattura. This book was released on 2014-09-12 with total page 1208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Materials Mechanics and Manufacturing III written by Mounir Ben Amar and published by Springer Nature. This book was released on with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gears written by Vincenzo Vullo and published by Springer Nature. This book was released on 2020-02-21 with total page 691 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the geometric and kinematic design of the various types of gears most commonly used in practical applications, also considering the problems concerning their cutting processes. The cylindrical spur and helical gears are first considered, determining their main geometric quantities in the light of interference and undercut problems, as well as the related kinematic parameters. Particular attention is paid to the profile shift of these types of gears either generated by rack-type cutter or by pinion-rack cutter. Among other things, profile-shifted toothing allows to obtain teeth shapes capable of greater strength and more balanced specific sliding, as well as to reduce the number of teeth below the minimum one to avoid the operating interference or undercut. These very important aspects of geometric-kinematic design of cylindrical spur and helical gears are then generalized and extended to the other examined types of gears most commonly used in practical applications, such as straight bevel gears; crossed helical gears; worm gears; spiral bevel and hypoid gears. Finally, ordinary gear trains, planetary gear trains and face gear drives are discussed. This is the most advanced reference guide to the state of the art in gear engineering. Topics are addressed from a theoretical standpoint, but in such a way as not to lose sight of the physical phenomena that characterize the various types of gears which are examined. The analytical and numerical solutions are formulated so as to be of interest not only to academics, but also to designers who deal with actual engineering problems concerning the gears
Download or read book DDSim a Hierarchical Probabilistic Multiscale Damage and Durability Simulation Methodology written by John M. Emery and published by . This book was released on 2007 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Topics in Modal Analysis Parameter Identification Volume 9 written by Brandon J. Dilworth and published by Springer Nature. This book was released on 2023-12-08 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topics in Modal Analysis, Testing & Parameter Identification, Volume 9: Proceedings of the 41st IMAC, A Conference and Exposition on Structural Dynamics, 2023, the ninth volume of ten from the Conference brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Modal Analysis, Modal Testing and Modal Parameter Identification including papers on: Analytical Methods Modal Applications Basics of Modal Analysis Experimental Techniques Operational Modal Analysis Modal Parameter Identification Novel Techniques Rotating Machinery Additive Manufacturing Applications Biomedical Applications
Download or read book Proceedings of Fatigue Durability and Fracture Mechanics written by S. Seetharamu and published by Springer. This book was released on 2017-11-01 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the proceedings of Fatigue Durability India 2016, which was held on September 28–30 at J N Tata Auditorium, Indian Institute of Science, Bangalore. This 2nd International Conference & Exhibition brought international industrial experts and academics together on a single platform to facilitate the exchange of ideas and advances in the field of fatigue, durability and fracture mechanics and its applications. This book comprises articles on a broad spectrum of topics from design, engineering, testing and computational evaluation of components and systems for fatigue, durability, and fracture mechanics. The topics covered include interdisciplinary discussions on working aspects related to materials testing, evaluation of damage, nondestructive testing (NDT), failure analysis, finite element modeling (FEM) analysis, fatigue and fracture, processing, performance, and reliability. The contents of this book will appeal not only to academic researchers, but also to design engineers, failure analysts, maintenance engineers, certification personnel, and R&D professionals involved in a wide variety of industries.
Download or read book Encyclopedia of Computational Mechanics written by Erwin Stein and published by . This book was released on 2004 with total page 870 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Encyclopedia of Computational Mechanics provides a comprehensive collection of knowledge about the theory and practice of computational mechanics.
