A three‐dimensional strain concentration equation for countersunk holes

2008 ◽  
Vol 43 (2) ◽  
pp. 75-85 ◽  
Author(s):  
A Bhargava ◽  
K N Shivakumar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Concentration Factor ◽  
Three Dimensional ◽  
Structural Elements ◽  
Element Analysis ◽  
Strain Concentration ◽  
Wide Range ◽  
Dimensional Equation ◽  
Concentration Equation

Countersunk rivets are used to join components to achieve aerodynamic or hydrodynamic surfaces. At countersunk holes, three‐dimensional stress and strain concentrations occur. Previously, the present authors developed a three‐dimensional equation for the stress concentration factor Kt through a detailed finite element analysis. This paper extends the study to include an equation for three‐dimensional strain concentration factor Ktε using a similar approach. The resulting equation was verified by finite element analysis for a wide range of countersunk hole configurations and plate sizes. Results showed that the maximum strain concentration is at the countersunk edge. The developed equation is within 5 per cent of the finite element results for all practical cases. It was also found that the Ktε and Kt expressions are similar and Ktε≥ Kt. The maximum difference between the two is 8 per cent (for = 0.3) or 2 for straight‐shank holes and about 2/2 for countersunk holes. The proposed equation is a valuable tool for strain‐based design of structural elements.

Numerical Investigation of Stress Concentration Factor at Irregular Corrosion Pit Under Tension-Torsion Loading

2014 ◽  
Author(s):  
Yuhui Huang ◽  
Chengcheng Wang ◽  
Shan-Tung Tu ◽  
Fu-Zhen Xuan ◽  
Takamoto Itoh
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Aspect Ratio ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Three Dimensional ◽  
Element Analysis ◽  
Stress Concentration Factors ◽  
Local Dissolution

Finite element analysis is adopted to study the stress concentration of pit area under tension-torsion loading. The stress concentration factors under regular evolution and irregular evolution of pits are investigated by conducting a series of three-dimensional semi-elliptical pitted models. Based on the finite element analysis, it can be concluded that pit aspect ratio (a/2c) is a significant parameter affecting stress concentration factor (SCF) for regular evolution pits. Pits, having higher aspect ratio, are very dangerous form and can cause significant reduction in the load carrying capacity. When local dissolution occurs in the pitting area, SCF will have a sharp increase, it is more probable for a crack to initiate from these areas compared with pits for regular evolution. Furthermore, local dissolution coefficient is proposed to study effect of local dissolution within the pit on SCF.

Error Analysis on Finite Element Modeling of Involute Spur Gears

2005 ◽  
Vol 128 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Jian D. Wang ◽  
Ian M. Howard
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Contact Problems ◽  
3D Analysis ◽  
Spur Gears ◽  
Mesh Stiffness ◽  
Element Analysis ◽  
Face Width ◽  
Wide Range

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.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

Sign in / Sign up

Export Citation Format

Share Document