scholarly journals A Three-Dimensional Elastic-Plastic Contact Analysis of Vickers Indenter on a Deep Drawing Quality Steel Sheet

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2153 ◽  
Author(s):  
Tomasz Trzepiecinski ◽  
Hirpa G. Lemu
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Deep Drawing ◽  
Three Dimensional ◽  
Hardness Test ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Quality Steel ◽  
Vickers Indenter ◽  
Pile Up

Three-dimensional finite element-based numerical analysis of Vickers indenter hardness test was conducted to investigate the effect of frictional conditions and material anisotropy on indentation results of deep drawing quality steel sheets. The strain hardening properties and Lankford’s coefficient were determined through the uniaxial tensile tests. The numerical computations were carried out using ABAQUS nonlinear finite element (FE) analysis software. Numerical simulations taken into account anisotropy of material described by Hill (1948) yield a criterion. The stress and strain distributions and loading–unloading characteristics were considered to study the response of the material. It was found that the hardness values seemed to be influenced by the value of the friction coefficient due to the pile-up phenomenon observed. The increasing of the friction coefficient led to a decrease of the pile-up value. Moreover, the width of the pile-ups differed from each other in the two perpendicular directions of measurement. Frictional conditions did not significantly affect the maximum force and the character of load–displacement curves. Frictional regime between the indenter and workpiece caused that the region of maximum residual stresses to be located in the subsurface.

scholarly journals Determination of Forming Limits Based on Finite Element Simulations

2021 ◽  
Author(s):  
Fuhui Shen ◽  
Kai Chen ◽  
Junhe Lian ◽  
Sebastian Münstermann
Keyword(s):  
Finite Element ◽  
Damage Mechanics ◽  
Tensile Tests ◽  
Finite Element Simulations ◽  
Experimental Results ◽  
Uniaxial Tensile ◽  
Anisotropic Plasticity ◽  
Forming Limits ◽  
Dog Bone ◽  
Spatio Temporal

Two categories of experiments have been performed to obtain the experimental forming limits of a ferritic stainless steel from uniaxial to equibiaxial tension, including Nakajima tests and tensile tests of flat specimens with different geometries of the central hole as well as the notched dog bone. The plasticity behavior of the investigated material is described using an evolving non-associated anisotropic plasticity model, which is calibrated based on experimental results of uniaxial tensile tests along different loading directions. A damage mechanics model is calibrated and validated based on the global force and displacement response of tensile tests. Finite element simulations of the Nakajima tests and the tensile tests of various geometries have been performed using the anisotropic material model. A novel spatio-temporal method is developed to evaluate the forming limits under different stress states by quantitatively characterizing the plastic strain distribution on the specimen surface. The forming limits have been independently determined from finite element simulation results of tensile specimens and Nakajima specimens using the spatio-temporal evaluation method. The forming limits obtained from numerical simulations of these two types of experiments are in good agreement with experimental results.

Investigating the Effects of the Friction Coefficient and Tool Geometry on the Cup Thickness in the Deep Drawing Process of SPXI250 Alloy

2013 ◽  
Author(s):  
Iman Rostamsowlat ◽  
Ahmad Afsari ◽  
Maziar Janghorban
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Deep Drawing ◽  
The Other ◽  
Tool Geometry ◽  
Drawing Process ◽  
Nose Radius ◽  
Deep Drawing Process ◽  
Simulation Results ◽  
Thickness Variations

In this paper, effects of friction coefficient and tool geometry on the thickness variations of a cylindrical cup were studied. Blank is made of SPXI250 alloy sheet which was analyzed by Finite Element Method (FEM). This not been studied yet. Finite Element modeling of the deep drawing process was conducted using ABAQUS/EXPLICIT software. A set of appropriate die and punch were designed for experimental tests. The results of the simulation showed that a change in the friction coefficient of the die-blank interface leads to a significant changes in the cup thickness. Moreover, the results revealed that the influence of die nose radius on the final cup thickness variations is greater than that of the punch nose radius. The simulation results of this study were compared with the experimental results and those of the other investigators’. The comparisons of the experimental and simulation results with those of the other researchers were so satisfactory.

Incorporate Research on Scratching and Uniaxial Tension of Three-Dimensional Microconstruction Simulation Based on Molecular Dynamic

2007 ◽  
Author(s):  
Yingchun Liang ◽  
Jiaxuan Chen ◽  
Qingshun Bai ◽  
Yulan Tang ◽  
Mingjun Chen
Keyword(s):  
Uniaxial Tension ◽  
Diamond Tool ◽  
Three Dimensional ◽  
Strain Curve ◽  
Uniaxial Tensile ◽  
Stress Strain Curve ◽  
Uniaxial Load ◽  
Residual Defect ◽  
Simulation Based ◽  
Pile Up

A method of incorporating research is proposed on scratching and uniaxial tension based on molecular dynamics (MD) with embodied atom method (EAM) for single copper in this paper. The process of tri-pyramid diamond tool scratching the single copper on the (010) plane is simulated under different penetrated depths. The details of scratching process and uniaxial tension are depicted in atomic view. The phenomena of heal-up surface, dislocations and burr are shown after the workpiece is scratched and the principle of that is attempted to analyze. The defects of the surface and subsurface of the workpiece scratched are represented and analyzed by the perspective of dislocations and radial distribution function (RDF). Whereafter the uniaxial tensile simulation of the “real” workpiece after scratching is performed. The mechanism of deformation and the details of change under the uniaxial load are analysed through the stress-strain curve that is combined with the perspective of atom. From simulations results, it is found that the dislocations only occur on the surface and subsurface of workpiece at the small scratching depth, while the dislocations are nucleated and emitted in front of tool and beneath the tool under the deep scratching depth. Dislocations disappear when they propagate to the surface. After the tool escapes the workpiece, the atoms on surface of the workpiece scratched heal up to some extent by the inter force of atoms, while some of the pile-up atoms on surface of tool are attracted backwards surface of workpiece, then form the burr, and others of those atoms are absorbed on the tool’s surface. The number of defects from surface and inner of workpiece increase when the scratching depth is doubled. The order of crystal decreases, especially long range order. It is shown that the penetration depth into the workpiece during scratching affects both surface pile-up and residual defect generation that is important in assessing the change of material properties after being scratched. In the process of the simulation of uniaxial load, the yield stress decrease with the increasing depth of cutting, and dislocations are nucleated at the bottom of groove, especially at the position where the tool escaped nearby burr firstly, and dislocations at ∼45° are observed. It shows that groove is the source of the dislocations aroused. The break-up point is near to the middle of workpiece with increasing depth with groove.

Determining Representative Stress and Representative Strain in Deriving Indentation Flow Curves Based on Finite Element Analysis

2005 ◽  
Vol 297-300 ◽  
pp. 2152-2157 ◽  
Author(s):  
Eun Chae Jeon ◽  
Min Kyung Baik ◽  
Sung Hoon Kim ◽  
Baik Woo Lee ◽  
Dong Il Kwon
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Indentation Test ◽  
Plastic Property ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Flow Curves ◽  
Element Analysis ◽  
Representative Strain ◽  
Instrumented Indentation Test

A new method [1] to evaluate indentation flow curves using an instrumented indentation test has been applied to many materials for several years. Though the method produces relatively good results compared to uniaxial tensile tests, a few parameters had not been verified by theoretical or numerical methods. In this study, proportional constants of representative strain and representative stress were verified using finite element analysis and proven to be unaffected by the elastic property and strain level. The constants were generally dependent on the plastic property; however, one combination of the constants is independent of all properties. The values of this combination are consistent with early research and produced overlapping indentation flow curves with uniaxial curves.

Finite Element Analysis and Deep Drawing of Cylindrical Cups with 5A90 Al-Li Alloy Sheets

2011 ◽  
Vol 66-68 ◽  
pp. 76-81
Author(s):  
Gao Shan Ma ◽  
Han Ying Wang ◽  
Song Yang Zhang ◽  
Min Wan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Deep Drawing ◽  
Uniaxial Tensile ◽  
Element Analysis ◽  
Corner Radius ◽  
The Finite Element Analysis ◽  
Forming Temperature ◽  
Cylindrical Cup ◽  
Cup Drawing

The cylindrical cup drawing of 5A90 Aluminum-Lithium alloy sheets at various forming conditions was studied by both the experimental approach and the finite element analysis. The uniaxial tensile tests and forming limit tests of 5A90 Al-Li alloy sheets at various temperatures were first carried out. The tests results were then employed in the finite element simulations to investigate the effects of process parameters, such as forming temperature, holder force, and die corner radius, on the formability of cylindrical cup drawing with 5A90 sheets. In order to validate the finite element analysis, the corresponding deep drawing tests were also carried out. It is shown that the simulation results are in qualitative agreement with the experimental observations. The optimal forming temperature, diameter of blank, holder force, punch radius and die corner radius were then determined for the cylindrical cup drawing of 5A90 sheets, and the limit drawing ratio (LDR) reached 2.4 in the optimal parameter conditions.

Torque capacity of the multilayer interference fit based on a friction coefficient prediction model

2021 ◽  
pp. 135065012110397
Author(s):  
Ke Ning ◽  
Jianmei Wang ◽  
Dan Xiang ◽  
Dingbang Hou
Keyword(s):  
Finite Element ◽  
Theoretical Model ◽  
Friction Coefficient ◽  
Prediction Model ◽  
Three Dimensional ◽  
Element Model ◽  
Maximum Relative Error ◽  
Interference Fit ◽  
Mathematical Expressions ◽  
Torque Capacity

This paper proposes the theoretical model of a multilayer interference fit and gives out the relational expression between radial interference and friction coefficient. Taking the typical wind turbine's shrink disk of a three-layer interference fit structure as an example, special experimental equipment is developed to test the torque capacity. Based on experimental results and the theoretical model, the mathematical expressions of radial interference and assembly stroke for friction coefficient are obtained by polynomial fitting, and the prediction model of friction coefficient is established. The three-dimensional finite element model of a shrink disk is constructed by applying the friction coefficient prediction model. With the mathematical expressions of radial interference and assembly stroke for the torque capacity, the rules of main dimension parameters and torque capacity are analyzed. The maximum relative error between experiment and simulation is 8.2%, which shows the feasibility of finite element simulation. The results of our study have certain guidance for the prediction of friction coefficient and the manufacture of the multilayer interference fit.

Experimental Research on the performance of HIGH temperature bearing steel Cr4Mo4V

2021 ◽  
Vol 14 ◽  
Author(s):  
Zenan Chu ◽  
Qiang He
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Friction Coefficient ◽  
Three Dimensional ◽  
Hardness Test ◽  
Surface Friction ◽  
Bearing Steel ◽  
Metallographic Analysis ◽  
Element Analysis ◽  
Friction Resistance

Background:: The Cr4Mo4V steel is widely used in high temperature bearings because of its excellent high temperature performance. According to the research status of Cr4Mo4V at home and abroad, this paper explores its mechanical properties and friction properties at high temperatures. Objective:: To characterize the composition, microstructure and properties of Cr4Mo4V steel and to explore its tensile properties, hardness and friction properties at high temperature. Methods: Many methods are adopted, such as chemical element analysis, metallographic analysis, hardness test, tensile test, damping test, friction test and so on. Results: The microstructure of Cr4Mo4V is tempered martensite. The hardness and maximum tensile strength of Cr4Mo4V decrease with temperature increasing. The grain of the Cr4Mo4V steel after heating gets refined and the grain boundary increases. At room temperature, the surface friction coefficient and wear rate of Cr4Mo4V steel decreases. Moreover, Cr4Mo4V steel-ceramic ball shows the best friction resistance. At high temperature, the friction coefficient and the wear of Cr4Mo4V steel firstly decrease with temperature increasing and then increase sharply at 200°C. Conclusion: With the increase of temperature, the hardness, breaking force and tensile strength of Cr4Mo4V bearing steel decrease, whereas the friction property increases. By analyzing the three-dimensional morphology of different wear samples, the optimal working temperature of Cr4Mo4V steel for bearing is 200°C.

scholarly journals A New Multi-Level Assessment Procedure for Corroded Line Pipe

2000 ◽  
Author(s):  
Duane S. Cronin ◽  
Roy J. Pick
Keyword(s):  
Three Dimensional ◽  
Strain Curve ◽  
Tensile Tests ◽  
Assessment Method ◽  
Uniaxial Tensile ◽  
Assessment Procedure ◽  
Element Analysis ◽  
Line Pipe ◽  
Experimental Database ◽  
Multi Level

A new assessment method to predict the failure pressure of corrosion defects in line pipe has been developed. Comparison to an experimental database shows that this new assessment procedure has advantages over existing techniques. The implementation of this method is proposed in a multi-level assessment procedure. The assessment levels are organized in terms of increasing complexity, with Level I being a lower bound solution and requiring only the maximum defect depth. The new assessment method requires detailed corrosion geometry measurements and is proposed as a Level II. Three dimensional elastic-plastic finite element analysis is proposed for the Level III. These methods assume the true stress-strain curve of the material is known, which can be determined from uniaxial tensile tests. When these material properties are unknown, the currently accepted codes are suggested for defect evaluation.

Comparative Study of Predictive Finite Element Methods for Mechanical Properties in 2D Woven Carbon/Carbon Composites

2008 ◽  
Vol 59 ◽  
pp. 116-119
Author(s):  
Joshim Ali ◽  
Derek Buckthorpe ◽  
Allister Cheyne ◽  
Johar Farooqi ◽  
Paul M. Mummery
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Tensile Tests ◽  
Unit Cell ◽  
Carbon Composites ◽  
Fe Model ◽  
Dimensional Finite Element ◽  
Composite Microstructure ◽  
Tomographic Data ◽  
Three Dimensional Finite Element

Three-dimensional finite element (FE) methods are used to predict the Young’s modulus of two types of 2D woven carbon/carbon composites. Tensile tests are performed to validate the predictions. The results indicate that a novel image-based route in generating FE meshes gave strong agreement with experimental data, while a comparative unit cell FE model of the structure was found to be poorer. The differences between the image-based and unit cell methodologies were the consideration of the finer architectures of the composites and their porosity. The image-based approach highlighted true porosity in the structure due to meshes forming directly from X-ray tomographic data. However, the finer fibre architectures of the composites were compromised because of limitations in the pixel resolutions employed during the initial scanning process. In comparison, the unit cell models were based solely on idealisations of the composite microstructure, in which porosity was neglected.

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