Material Modeling for Autofrettage Stress Analysis Including the “Single Effective Material”

2008 ◽  
Author(s):  
Anthony P. Parker ◽  
Michael C. Gibson ◽  
Amer Hameed ◽  
Edward Troiano ◽  
John G. Hetherington
Keyword(s):  
Stress Analysis ◽  
Numerical Solutions ◽  
Material Behavior ◽  
Material Modeling ◽  
Equivalent Material ◽  
Element Analysis ◽  
Adjustment Procedure ◽  
Analysis Process ◽  
Real Material ◽  
Accurate Procedure

Analytical and numerical stress analysis of the autofrettage process has made great strides in the last few years. The major challenge is no longer the stress analysis process but the incorporation of ‘real’ material behavior, including Bauschinger effect. This means that material properties may vary at every radial location within the tube. In this paper it is demonstrated that Finite Element Analysis (FEA) may be accomplished using a ‘user programmable feature’ within a non-linear FEA or, more simply using an elastic modulus and Poisson’s ratio adjustment procedure within a linear-elastic FEA. The results of these two methods are shown to be in agreement with each other and with an independent numerical analysis. It is further demonstrated that numerical solutions may be obtained using a single ‘fictitious’ material. This is called a ‘single equivalent material’ (SEMAT). Whilst this requires a very small number of iterations for accurate convergence, it dramatically reduces the material-modeling challenges. Furthermore, SEMAT may be implemented into an analytical procedure thereby permitting highly accurate modeling of a real material whose unloading behavior varies with radius. Comparisons indicate that this is a robust, accurate procedure.

Material Modeling for Autofrettage Stress Analysis Including the “Single Effective Material”

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Anthony P. Parker ◽  
Michael C. Gibson ◽  
Amer Hameed ◽  
Edward Troiano
Keyword(s):  
Stress Analysis ◽  
Analytical Procedure ◽  
Numerical Solutions ◽  
Material Behavior ◽  
Material Modeling ◽  
Element Analysis ◽  
Adjustment Procedure ◽  
Analysis Process ◽  
Real Material ◽  
Accurate Procedure

Analytical and numerical stress analyses of the autofrettage process have made great strides in the last few years. The major challenge is no longer the stress analysis process but the incorporation of “real” material behavior, including Bauschinger effect. This means that material properties may vary at every radial location within the tube. In this paper, it is demonstrated that finite element analysis (FEA) may be accomplished using a “user programmable feature (UPF)” within a nonlinear FEA or, more simply using an elastic modulus and Poisson’s ratio adjustment procedure (EMPRAP) within a linear-effective FEA. The results of these two methods are shown to be in agreement with each other and with an independent numerical analysis. It is further demonstrated that the numerical solutions may be obtained using a single “fictitious” material. This is called a single effective material (SEMAT). While this requires a very small number of iterations for accurate convergence, it dramatically reduces the material-modeling challenges. Furthermore, SEMAT may be implemented into an analytical procedure thereby permitting highly accurate modeling of a real material whose unloading behavior varies with radius. Comparisons indicate that this is a robust, accurate procedure.

Custom Material Modeling Within FEA for Use in Autofrettage Simulation

2007 ◽  
Author(s):  
Michael C. Gibson ◽  
Amer Hameed ◽  
John G. Hetherington ◽  
Anthony P. Parker
Keyword(s):  
Plastic Strain ◽  
Close Agreement ◽  
Bauschinger Effect ◽  
Complex Loading ◽  
Material Behavior ◽  
Material Modeling ◽  
Element Analysis ◽  
Strong Function ◽  
Adjustment Procedure ◽  
End Conditions

Finite Element Analysis (FEA) has been widely adopted. For autofrettage analysis, in order to represent real conditions and materials, it is necessary to properly model end conditions and material behavior, in particular the loss of compressive strength following prior tensile plastic strain, termed the ‘Bauschinger Effect’. The latter is a strong function of prior plastic strain and therefore of location; this implies the need to model a different material unloading behavior at each location in the tube. Two possible methods of implementing such a behavior within FEA are examined. These are an ‘elastic modulus and Poisson’s ratio adjustment procedure’ (EMPRAP) and a ‘user programmable feature’ (UPF). Finally the results are compared to an independent, non-FEA, EMPRAP numerical solution. Close agreement between all three methods is demonstrated. The UPF approach, validated here, is applicable in more complex loading scenarios.

scholarly journals Stress Analysis and Design of Main Reducer Housing Using Finite Element Method

2018 ◽  
Vol 221 ◽  
pp. 04008
Author(s):  
S. Wang
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Numerical Comparison ◽  
Original Design ◽  
Element Analysis ◽  
Time Saving ◽  
Analysis And Design ◽  
Analysis Process ◽  
Comparison Results ◽  
Strength And Stiffness

The main reducer housing takes over the shaft loads from gear engagement and transmits to other components, such as differential, semiaxle and driving wheels, so the main reducer housing with enough strength and stiffness is very important. Some factors preventing it from failure need to be taken into consideration when design it. To design a main reducer housing with better performance, in this paper, FEA (Finite Element Analysis) is used to analysis the main reducer housing and to find out some big stress regions. Then, some modifications are proposed to eliminate those big stress regions and obtain a reliable main reducer housing. During the analysis process, an annulus model is built and the reaction forces between the differential bearing seats and axle housing are calculated to determine whether they contact with each other. Finally, some design methods and improvements of the original design main reducer housing are proposed. And numerical comparison results of the stress distribution of the original and improved main reducer housing validate the effectiveness of the proposed methods and modifications in this paper. Those stress analysis and modifications in this paper are time-saving and money-saving before mass production.

Determination of Real Material Properties From Nanoindentation Experiments

2003 ◽  
Author(s):  
L. Kogut ◽  
K. Komvopoulos
Keyword(s):  
Elastic Modulus ◽  
Material Properties ◽  
Numerical Solutions ◽  
Material Behavior ◽  
Depth Sensing ◽  
Empirical Relations ◽  
Real Material ◽  
Alternative Approach ◽  
Material Hardness

In recent years, due to extensive development of depth-sensing indentation techniques, nanoindentation has been used to evaluate the mechanical properties of surface layers and thin films of different materials. However, current nanoindentation procedures are based on simplified assumptions about the material behavior during unloading and empirical relations of the contact area (e.g., Oliver and Pharr, 1992) with little input from analytical and numerical solutions. Therefore, it is unclear what properties can be measured using instrumented nanoindentation techniques and what is the validity of the present procedures for measuring reduced elastic modulus and material hardness. Thus, the main objective of the present study was to analyze the validity of the current approaches for determining material properties and to propose an alternative approach for measuring the reduced elastic modulus, yield strength, and material hardness.

Interactive Graphics for the Analysis of Tires

1985 ◽  
Vol 13 (3) ◽  
pp. 127-146 ◽  
Author(s):  
R. Prabhakaran
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Approximate Solutions ◽  
Interactive Graphics ◽  
Element Analysis ◽  
Analysis Process ◽  
Physical Problems ◽  
The Finite Element Analysis ◽  
Analysis Computer ◽  
Discretization Technique

Abstract The finite element method, which is a numerical discretization technique for obtaining approximate solutions to complex physical problems, is accepted in many industries as the primary tool for structural analysis. Computer graphics is an essential ingredient of the finite element analysis process. The use of interactive graphics techniques for analysis of tires is discussed in this presentation. The features and capabilities of the program used for pre- and post-processing for finite element analysis at GenCorp are included.

scholarly journals Impact of residual stress evoked by pyramidal embossing on the magnetic material properties of non-oriented electrical steel

2021 ◽  
Author(s):  
Ines Gilch ◽  
Tobias Neuwirth ◽  
Benedikt Schauerte ◽  
Nora Leuning ◽  
Simon Sebold ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Residual Stress ◽  
Magnetic Flux ◽  
Material Properties ◽  
Electrical Steel ◽  
Maximum Energy ◽  
Material Behavior ◽  
Electrical Machine ◽  
Element Analysis ◽  
Steel Sheets

AbstractTargeted magnetic flux guidance in the rotor cross section of rotational electrical machines is crucial for the machine’s efficiency. Cutouts in the electrical steel sheets are integrated in the rotor sheets for magnetic flux guidance. These cutouts create thin structures in the rotor sheets which limit the maximum achievable rotational speed under centrifugal forces and the maximum energy density of the rotating electrical machine. In this paper, embossing-induced residual stress, employing the magneto-mechanical Villari effect, is studied as an innovative and alternative flux barrier design with negligible mechanical material deterioration. The overall objective is to replace cutouts by embossings, increasing the mechanical strength of the rotor. The identification of suitable embossing geometries, distributions and methodologies for the local introduction of residual stress is a major challenge. This paper examines finely distributed pyramidal embossings and their effect on the magnetic material behavior. The study is based on simulation and measurements of specimen with a single line of twenty embossing points performed with different punch forces. The magnetic material behavior is analyzed using neutron grating interferometry and a single sheet tester. Numerical examinations using finite element analysis and microhardness measurements provide a more detailed understanding of the interaction of residual stress distribution and magnetic material properties. The results reveal that residual stress induced by embossing affects magnetic material properties. Process parameters can be applied to adjust the magnetic material deterioration and the effect of magnetic flux guidance.

Finite Element Analysis of Drum on the New Type Self-Driven Towing Machine for Cable

2011 ◽  
Vol 55-57 ◽  
pp. 664-669
Author(s):  
Jin Ning Nie ◽  
Hui Wang ◽  
De Feng Xie
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Analysis ◽  
Compressive Stress ◽  
Wire Rope ◽  
Ansys Software ◽  
Element Analysis ◽  
Structure Improvement ◽  
Improvement Measures ◽  
New Type

According to the situation that the dual-friction drums on the new type towing machine lack stress analysis when designed, the safety is difficult to test and verify. The pull of wire rope in various positions was derived and calculated, so both compressive stress and tangent friction force generated by the pull of wire rope were calculated. The result made by ANSYS software demonstrates the safety of the left drum which suffers from larger loads, structure improvement measures are put forward for the drum.

Stress Analysis and Structure Optimization for the Opening Flat Cover of Pressure Vessels

2012 ◽  
Vol 538-541 ◽  
pp. 3253-3258 ◽  
Author(s):  
Jun Jian Xiao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Analysis ◽  
Structure Optimization ◽  
Pressure Vessels ◽  
Secondary Stress ◽  
Element Analysis ◽  
Primary Stress ◽  
Flat Cover

According to the results of finite element analysis (FEA), when the diameter of opening of the flat cover is no more than 0.5D (d≤0.5D), there is obvious stress concentration at the edge of opening, but only existed within the region of 2d. Increasing the thickness of flat covers could not relieve the stress concentration at the edge of opening. It is recommended that reinforcing element being installed within the region of 2d should be used. When the diameter of openings is larger than 0.5D (d>0.5D), conical or round angle transitions could be employed at connecting location, with which the edge stress decreased remarkably. However, the primary stress plus the secondary stress would be valued by 3[σ].

Strength-based design of a sunflower stalk cutter machine design using finite element analysis and experimental validation

2021 ◽  
pp. 095440622110597
Author(s):  
Gürkan İrsel
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Analysis ◽  
Strain Gage ◽  
Experimental Validation ◽  
Experimental Studies ◽  
Fatigue Analysis ◽  
Structural Stress ◽  
Element Analysis ◽  
Strength Based

In this study, the total algorithm of the strength-based design of the system for mass production has been developed. The proposed algorithm, which includes numerical, analytical, and experimental studies, was implemented through a case study on the strength-based structural design and fatigue analysis of a tractor-mounted sunflower stalk cutting machine (SSCM). The proposed algorithm consists of a systematic engineering approach, material selection and testing, design of the mass criteria suitability, structural stress analysis, computer-aided engineering (CAE), prototype production, experimental validation studies, fatigue calculation based on an FE model and experimental studies (CAE-based fatigue analysis), and an optimization process aimed at minimum weight. Approximately 85% of the system was designed using standard commercially available cross-section beams and elements using the proposed algorithm. The prototype was produced, and an HBM data acquisition system was used to collect the strain gage output. The prototype produced was successful in terms of functionality. Two- and three-dimensional mixed models were used in the structural analysis solution. The structural stress analysis and experimental results with a strain gage were 94.48% compatible in this study. It was determined using nCode DesignLife software that fatigue damage did not occur in the system using the finite element analysis (FEA) and experimental data. The SSCM design adopted a multi-objective genetic algorithm (MOGA) methodology for optimization with ANSYS. With the optimization solved from 422 iterations, a maximum stress value of 57.65 MPa was determined, and a 97.72 kg material was saved compared to the prototype. This study provides a useful methodology for experimental and advanced CAE techniques, especially for further study on complex stress, strain, and fatigue analysis of new systematic designs desired to have an optimum weight to strength ratio.

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