An Approximate Model to Calculate Foldover and Strains During Cold Upsetting of Cylinders Part II: Use of the Foldover Model to Estimate Friction

1990 ◽  
Vol 112 (3) ◽  
pp. 267-271 ◽  
Author(s):  
O. M. Ettouney ◽  
K. A. Stelson
Keyword(s):  
Finite Element Analysis ◽  
Approximate Model ◽  
Ring Test ◽  
Internal Diameter ◽  
Cold Upsetting ◽  
Element Analysis ◽  
New Approach ◽  
The Finite Element Analysis ◽  
Friction Calibration ◽  
Good Agreement

This paper addresses an approach to calculate the friction coefficient during nonuniform compression of cylinders. The approach combines new friction-calibration curves (prepared using the finite-element analysis) that relate friction to workpiece shape and the foldover model from Part I. Foldover in upsetting is used in the same way that the change in internal diameter is used in the ring test to determine friction. However, the new approach has the advantage that measurements are taken directly from the workpiece. Comparisons of friction values calculated from the ring test and the new approach showed good agreement.

An Approximate Model to Calculate Foldover and Strains During Cold Upsetting of Cylinders Part I: Formulation and Evaluation of the Foldover Model

1990 ◽  
Vol 112 (3) ◽  
pp. 260-266 ◽  
Author(s):  
O. M. Ettouney ◽  
K. A. Stelson
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Approximate Model ◽  
Ring Test ◽  
Forming Limit ◽  
Cold Upsetting ◽  
Element Analysis ◽  
Forming Limit Diagrams ◽  
Volume Equations ◽  
Friction Calibration

In this paper, a new approximate model to calculate foldover of a cylinder undergoing nonuniform compression test (simple upsetting) is presented. The model is formulated using constant-volume equations and workpiece geometry. In addition to foldover, the model can be used to calculate equatorial-axial strains. This eliminates the need for inscribing grids (when determining forming-limit diagrams) on the cylinder’s free surface to find these strains. Combined with friction-calibration curves (prepared using finite-element analysis) that relate foldover to friction, the model enables one to estimate the friction coefficient. This eliminates the need for a separate test (e.g., the ring test) to determine friction or evaluate type of lubrication to be used. When compared to finite-element results and experiments, the new model showed excellent results in calculating foldover, strains, and friction coefficient.

Plastic Effects on High Cycle Fatigue at the Edge of Contact of Turbine Blade Fixtures

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
C. H. Richter ◽  
U. Krupp ◽  
M. Zeißig ◽  
G. Telljohann
Keyword(s):  
Finite Element Analysis ◽  
High Cycle Fatigue ◽  
Turbine Blades ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Element Analysis ◽  
Notched Specimens ◽  
The Finite Element Analysis ◽  
Slip Region ◽  
Good Agreement

Slender turbine blades are susceptible to excitation. Resulting vibrations stress the blade's fixture to the rotor or stator. In this paper, high cycle fatigue at the edge of contact (EOC) between blade and rotor/stator of such fixtures is investigated both experimentally and numerically. Plasticity in the contact zone and its effects on, e.g., contact tractions, fatigue determinative quantities, and fatigue itself are shown to be of considerable relevance. The accuracy of the finite element analysis (FEA) is demonstrated by comparing the predicted utilizations and slip region widths with data gained from tests. For the evaluation of EOC fatigue, tests on simple notched specimens provide the limit data. Predictions on the utilization are made for the EOC of a dovetail setup. Tests with this setup provide the experimental fatigue limit to be compared to. The comparisons carried out show a good agreement between the experimental results and the plasticity-based calculations of the demonstrated approach.

Self-Loosening Mechanism of Nuts Due to Lateral Motion of Fastened Plate

2007 ◽  
Author(s):  
Yasumasa Shoji ◽  
Toshiyuki Sawa ◽  
Hiroshi Yamanaka
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bolted Joints ◽  
Lateral Motion ◽  
Element Analysis ◽  
New Approach ◽  
The Finite Element Analysis ◽  
Mechanical Element ◽  
Vibration Tests

As self-loosening of nuts is really a problem for bolted joints in practical use, countermeasures for the loosening is highly required. In this situation non-loosening fasteners are one of the resolutions for any fastened machinery as an essential mechanical element. Self-loosening of threaded bolt/nut systems has been researched in number of works and most researches were based on experiment and a few were based on the finite element analysis in these years. Using this new approach, various types of nuts can also be examined. Among these nuts eccentric nuts and slit nuts are especially expected to be the solution, as these nuts are reported to endure NAS vibration tests and were not loosened. In the authors’ previous paper, an eccentric nut and a normal nut were analyzed and compared in the aspect of loosening property. In this paper degree of loosening of various nuts was investigated by experiment and the FEA.

Life Assessment of Turbine Components Through Experimental and Numerical Investigations

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Dianyin Hu ◽  
Rongqiao Wang ◽  
Guicang Hou
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Life Prediction ◽  
Life Assessment ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Creep Fatigue ◽  
Turbine Component ◽  
Good Agreement

A new lifetime criterion for withdrawal of turbine components from service is developed in this paper based on finite element (FE) analysis and experimental results. Finite element analysis is used to determine stresses in the turbine component during the imposed cyclic loads and analytically predict a fatigue life. Based on the finite element analysis, the critical section is then subjected to a creep-fatigue test, using three groups of full scale turbine components, attached to an actual turbine disc conducted at 750 °C. The experimental data and life prediction results were in good agreement. The creep-fatigue life of this type of turbine component at a 99.87% survival rate is 30 h.

The Effect of the Die Temperature on the Solidification Behaviour of the Al/SiCp Metal Matrix Composite: A Comparative Study of Experimental and Finite Element Analysis

2014 ◽  
Vol 893 ◽  
pp. 314-319
Author(s):  
P. Gurusamy ◽  
S. Balasivanandha Prabu ◽  
R. Paskaramoorthy
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Time History ◽  
Cooling Curves ◽  
Element Analysis ◽  
Solidification Behaviour ◽  
The Finite Element Analysis ◽  
Die Temperature ◽  
Temperature Time ◽  
Good Agreement

This paper discusses the influence of die temperature on the solidification behaviour of A356/SiCp composites fabricated by squeeze casting method. Information on the solidification studies of squeeze cast composites is somewhat scarce. Experiments were carried out by varying the die temperatures for cylindrical shaped composite castings K-type thermocouples were interfaced to the die and the temperature-time history was recorded to construct the cooling curves. The cooling curves are also predicted from the finite element analysis (FEA) software ANSYS 13. The experimental and predicted cooling curves are not in good agreement. In addition to, the experimental and theoretical solidification times are studied. It was understood that the increase in the die temperature decreases the cooling rate.

Deep Drawing of Square-Shaped Sheet Metal Parts, Part 1: Finite Element Analysis

1993 ◽  
Vol 115 (1) ◽  
pp. 102-109 ◽  
Author(s):  
S. A. Majlessi ◽  
D. Lee
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Membrane Properties ◽  
Computationally Efficient ◽  
Element Analysis ◽  
Sheet Metal Parts ◽  
Part Geometry ◽  
Analysis Technique ◽  
The Finite Element Analysis ◽  
Good Agreement

The process of square-cup drawing is modeled employing a simplified finite element analysis technique. In order to make the algorithm computationally efficient, the deformation (total strain) theory of plasticity is adopted. The solution scheme is comprised of specifying a mesh of two-dimensional finite elements with membrane properties over the deformed configuration of the final part geometry. The initial positions of these elements are then computed by minimization of the potential energy, and therefore the strain distributions are determined. In order to verify predictions made by the finite element analysis method, a drawing apparatus is built and various drawing experiments are carried out. A number of circular and square cups are drawn and strain distributions measured. It is observed that there is generally a good agreement between computed and measured results for both axisymmetric and nonaxisymmetric cases.

Experimental and finite element investigation of a local dent on a pressurized pipe

1992 ◽  
Vol 27 (3) ◽  
pp. 177-185 ◽  
Author(s):  
L S Ong ◽  
A K Soh ◽  
J H Ong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surface Defect ◽  
Peak Stress ◽  
Plastic Collapse ◽  
Hoop Strain ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Local Dent ◽  
Good Agreement

The problem of a local dent on a pressurized pipe is studied in this paper. Two case problems of dent are considered - a plain local dent (a smooth local dent without a surface defect), and a local dent associated with a loss of thickness defect. The strain gauging test and the finite element analysis on the plain local dent showed that the strain distributions in the local dent are different from those of a long and continuous dent. The maximum hoop strain in the local dent is located at the flank of the dent, along the dent axial axis, whereas in the case of the long dent, it is located at the root of the dent. In addition, the peak stress in the local dent is generally lower than that in the long dent. To estimate the stress concentration in the local dent using the analysis for the long dent would be grossly overestimated. The burst pipe tests on 17 dented pipes showed that the pipe failures were generally insensitive to the existence of the local dents. The pipe failures were found to be due to the loss-of-thickness defect. The comparison of results between the burst pipe tests and the plastic collapse formula shows reasonably good agreement.

Nonlinear Finite Element Analysis of Steel-Encased Composite Continuous Beams with High Strength Materials

2013 ◽  
Vol 648 ◽  
pp. 59-62
Author(s):  
Qi Yin Shi ◽  
Yi Tao Ge ◽  
Li Lin Cao ◽  
Zhao Chang Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Error Control ◽  
High Strength ◽  
Element Model ◽  
Test Results ◽  
Element Analysis ◽  
Continuous Beams ◽  
The Finite Element Analysis ◽  
Good Agreement

In this study, based on the test of the high strength materials of steel-encased concrete composite continuous beam, the ultimate flexural capacity of 8 composite continuous beams are analyzed by using the finite element analysis software ABAQUS. Numerical results show that it is a very good agreement for the load-deflection curves which obtained by finite element method (FEM) and those by the test results, and the error control is less than 8.5%. When selecting and utilizing appropriate cyclic constitutive model, element model and failure criterion of high strength steel and high strength concrete, the accuracy of the calculation can be improved better.

Finite element analysis for precision cold forging of helical gear using recurrent boundary conditions

1998 ◽  
Vol 212 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Y B Park ◽  
D Y Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Boundary Conditions ◽  
Three Dimensional ◽  
Helical Gear ◽  
Cold Forging ◽  
Rigid Plastic ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Good Agreement

In metal forming, there are problems with recurrent geometric characteristics without explicitly prescribed boundary conditions. In such problems, so-called recurrent boundary conditions must be introduced. In this paper, as a practical application of the proposed method, the precision cold forging of a helical gear (which is industrially useful and geometrically complicated) has been simulated by a three-dimensional rigid-plastic finite element method and compared with the experiment. The application of recurrent boundary conditions to helical gear forging analysis is proved to be effective and valid. The three-dimensional deformed pattern by the finite element analysis is shown, and the forging load is compared with the experimental load. The profiles of the free surface of the workpiece show good agreement between the computation and the experiment.

Conformal Contact Between a Rubber Band and Rigid Cylinders

2012 ◽  
Vol 79 (4) ◽  
Author(s):  
Takuya Morimoto ◽  
Hiroshi Iizuka
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rubber Band ◽  
Element Analysis ◽  
Geometrical Nonlinearities ◽  
Pressure Distributions ◽  
The Finite Element Analysis ◽  
Theoretical Results ◽  
Conformal Contact ◽  
Good Agreement

We consider a conformal contact problem between a rubber band and rigid cylinders that involves geometrical and material nonlinearities. The rubber band is assumed to be incompressible, neo-Hookean rubber. From the geometry and elasticity of the band, we present simple formulas to estimate the force–stretch relations and the contact pressure distributions on the cylinder. We show that the theoretical results are in good agreement with those of the finite element analysis when the rubber band is thin enough to be negligible to the bending stiffness. This verifies that the theory can effectively take into account both the material and geometrical nonlinearities of the band under the present conditions.

Sign in / Sign up

Export Citation Format

Share Document