scholarly journals Discussion: “A Method of Selecting Grid Size to Account for Hertz Deformation in Finite Element Analysis of Spur Gears” (Coy, J. J., and Chao, C. Hu-Chih, 1982, ASME J. Mech. Des., 104, pp. 759–764)

1982 ◽  
Vol 104 (4) ◽  
pp. 764-765
Author(s):  
R. W. Cornell
1982 ◽  
Vol 104 (4) ◽  
pp. 759-764 ◽  
Author(s):  
J. J. Coy ◽  
C. Hu-Chih Chao

A method of selecting grid size for the finite element analysis of gear tooth deflection is presented. The method is based on a finite element study of two cylinders in line contact, where the criterion for establishing element size was that there be agreement with the classic Hertzian solution for deflection. Many previous finite element studies of gear tooth deflection have not included the full effect of the Hertzian deflection. The present results are applied to calculate deflection for the gear specimen used in the NASA spur gear test rig. Comparisons are made between the present results and the results of two other methods of calculation. The results have application in design of gear tooth profile modifications to reduce noise and dynamic loads.


2021 ◽  
Vol 31 (2) ◽  
pp. 36-49
Author(s):  
Lauro Miguel Lima Rocha ◽  
Marco Túlio Santana Alves

This paper deals with analyzing the structural influence of mass reliefs in spur gears. For this purpose, a system composed of pinion and a gear was designed, such that for gear several geometries were designed with different reliefs shapes and soul thicknesses. From the proposed geometries, finite element analysis (FEA) was performed, and the tooth stresses of each model were compared with the solid gear. From the results, it was observed that the tooth stresses are reduced in some cases. Besides, from the aforementioned cases, it is possible to observe that the maximum stresses may take place in its core instead of the teeth (rim area). On the other hand, based on other cases, the core thickness plays an important role as a criterion that defines the local stress.


Author(s):  
Benny Thomas ◽  
K Sankaranarayanasamy ◽  
S Ramachandra ◽  
SP Suresh Kumar

Various analytical methods have been developed by designers to predict gear tooth bending stress in asymmetric spur gears with an intention to improve the accuracy of predicted results and to reduce the need for time consuming finite element analysis at the early stages of gear design. Asymmetry in the drive and coast side of asymmetric spur gears poses difficulty in direct application of well-known procedures like American Gear Manufacturers Association and International Organization for Standardization in the prediction of gear tooth bending stress. In earlier works, ISO-6336-3 methodology was suitably modified and adapted to predict asymmetric spur gear tooth bending stress. This approach is based on certain assumptions on the location of critical section which could introduce error in the predicted maximum bending stress. The present work is to analytically predict gear tooth bending stress in normal contact ratio asymmetric spur gears based on a more rigorous analytical approach. This includes a fundamental study on the gear tooth orientation used to define the coordinate system, determination of maximum bending stress by search along the fillet profile and to obtain stress profile along the fillet. Gear tooth bending stress obtained from the present work using Search method is compared against the results obtained from earlier adapted International Organization for Standardization method and Finite Element Analysis. This study recommends a new coordinate system and method for analytical prediction of gear tooth bending stress in normal contact ratio asymmetric spur gears.


Author(s):  
Çağdaş Alagöz ◽  
M. A. Sahir Arıkan ◽  
Ö. Gündüz Bilir ◽  
Levend Parnas

Abstract A method and a computer program are developed for 3-D finite element analysis of long fiber reinforced composite spur gears, in which long fibers are arranged along tooth profiles. For such a structure, the gear is composed of two regions; namely the long fiber reinforced and the chopped fiber reinforced regions. Pre and post-processing modules of the program for the finite element analysis are written in Borland Delphi Pascal 3.0®. ABAQUS® is used for finite element analysis. Main inputs for the pre-processing module of the program are, information on basic gear geometry, gear drive data, material properties and long fiber reinforcement geometry. Finite element meshes are automatically generated and mesh information with other required data are written to a file in the input-file-format of ABAQUS®. Stresses are read from the output file of ABAQUS® by the post-processing module, and color-coded drawings for various stresses and failure index are displayed. For the long fiber reinforced region, failure indexes are calculated by using the tensor polynomial failure criterion. Effects of reinforcing thickness and location of long fibers on gear strength are investigated. Stresses and failure index are calculated for different materials and fiber volume ratios.


2005 ◽  
Vol 128 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Jian D. Wang ◽  
Ian M. Howard

Finite element analysis can incorporate two-dimensional (2D) modeling if the geometry, load, and boundary conditions meet the requirements. For many applications, a wide range of problems are solved in 2D, due to the efficiency and costs of computation. However, care has to be taken to avoid modeling errors from significantly influencing the result. When the application area is nonlinear, such as when modeling contact problems or fracture analysis, etc, the 2D assumption must be used cautiously. In this paper, a large number of 2D and three-dimensional (3D) gear models were investigated using finite element analysis. The models included contact analysis between teeth in mesh, a gear body (disk), and teeth with and without a crack at the tooth root. The model results were compared using parameters such as the torsional (mesh) stiffness, tooth stresses and the stress intensity factors that are obtained under assumptions of plane stress, plane strain, and 3D analysis. The models considered variations of face width of the gear from 5 mm to 300 mm. This research shows that caution must be used especially where 2D assumptions are used in the modeling of solid gears.


Sign in / Sign up

Export Citation Format

Share Document