Experimental and Numerical Investigations of a Split-Ring Test for Springback

2006 ◽  
Vol 129 (2) ◽  
pp. 352-359 ◽  
Author(s):  
Z. Cedric Xia ◽  
Craig E. Miller ◽  
Feng Ren
Keyword(s):  
Experimental Data ◽  
Thickness Distribution ◽  
Transversely Isotropic ◽  
Ring Test ◽  
Stress Distributions ◽  
Opening Displacement ◽  
Split Ring ◽  
Punch Force ◽  
Hardening Models ◽  
Cylindrical Cup

This paper presents an in-depth experimental and numerical investigation of a split-ring test, which provides a simple yet effective benchmark for correlating forming and springback predictive capabilities with experimental measurements. The experimental procedure consists of deep drawing a circular 6111-T4 aluminum alloy into a cylindrical cup of 55mm depth, crosscutting nine rings each of 5mm wide from the cup, splitting the rings, and measuring their opening displacement, i.e., the springback amount. Experimental data obtained included punch force trajectories, drawn cup profile, thickness distribution after forming, and the ring openings after splitting. A numerical model is built to analyze the process, and both transversely isotropic and fully orthotropic yield criteria are investigated. Simulation results are validated against experimental data. A detailed numerical analysis is also conducted for stress distributions in each ring after each step and their relationship to the total springback amount. Stress and strain signatures suggested that the test is well suited for validating material models, such as anisotropic yield surface models and hardening models.

Experimental and Numerical Investigations of a Split-Ring Test for Springback

2005 ◽  
Author(s):  
Z. Cedric Xia ◽  
Craig E. Miller ◽  
Feng Ren
Keyword(s):  
Experimental Data ◽  
Thickness Distribution ◽  
Transversely Isotropic ◽  
Ring Test ◽  
Stress Distributions ◽  
Opening Displacement ◽  
Split Ring ◽  
Punch Force ◽  
Hardening Models ◽  
Cylindrical Cup

This paper presents an in-depth experimental and numerical investigation of a split-ring test, which provides a simple yet effective benchmark for correlating forming and springback predictive capabilities with experimental measurements. The experimental procedure consists of deep drawing a circular 6111-T4 aluminum alloy into a cylindrical cup of 55mm depth, cross-cutting 9 rings of 5mm each from the cup, splitting the rings and measuring their opening displacement, i.e. the springback amount. Experimental data obtained included punch force trajectories, drawn cup profile, thickness distribution after forming, and the ring openings after splitting. A numerical model is built to analyze the process, and both transversely-isotropic and fully-orthotropic yield criteria are investigated. Simulation results are validated against experimental data. A detailed numerical analysis is also conducted for stress distributions in each ring after each step and their relationship to springback amount. Stress and strain signatures suggested that the test is well suited for validating material models such as anisotropic yield surface models and hardening models.

Sensitivity Analysis of Process Parameters in the Drawing and Ironing Processes

2013 ◽  
Vol 554-557 ◽  
pp. 2256-2265 ◽  
Author(s):  
Vasco M. Simões ◽  
Jeremy Coër ◽  
Hervé Laurent ◽  
M.C. Oliveira ◽  
J. Luís Alves ◽  
...  
Keyword(s):  
Process Parameters ◽  
Deep Drawing ◽  
Thickness Distribution ◽  
Experimental Tests ◽  
Contact Forces ◽  
Outer Diameter ◽  
Forming Process ◽  
Punch Force ◽  
Inner Radius ◽  
Cylindrical Cup

Deep drawing is one of the most important operations used in sheet metal forming. Within this, forming of cylindrical cup is one of the most widely studied deep drawing processes since it allows analysing the effect of different process parameters in phenomena such as earing, springback and ironing. In fact, during the deep drawing of a cylindrical cup the blank thickness gradually increases as the blank outer diameter is reduced to the die inner diameter, resulting in a thickness increase from a point near the bottom radius until the maximum value at the top of the cup. Therefore, if the gap between the punch and the die is not sufficiently large to allow the blank material to flow, ironing of the cup wall will occur. The ironing process typically imposes high contact forces, normal to the surface of the punch and the die, which can lead to the occurrence of galling, particularly for aluminium alloys. In this work an experimental device, adopted in previous studies, was used to analyse the influence of the lubricant conditions in the deep drawing of a cylindrical cup. The study considers an AA5754-O aluminium alloy blank with a diameter of 60 mm, which is fully deep drawn with a 33 mm diameter punch. Due to the forming conditions, the cup is deep drawn and ironing of the cup wall also occurs. The experimental tests were performed considering different amounts of lubricant in the blank surfaces in the contact with the die and with the blank-holder in order to better understand the influence of these tools on the process. The experimental study was complemented with numerical simulations, exploring the conditions induced by the ironing operation, quite challenging for the numerical simulation of the process using the finite element method. Besides the influence of the contact with friction conditions in the forming process (i.e. punch force evolution, thickness distribution along the cup wall and contact pressure), the influence of the die shoulder and inner radius were also analysed.

Anisotropic Porochemoelectroelastic Solution for an Inclined Wellbore Drilled in Shale

2013 ◽  
Vol 80 (2) ◽  
Author(s):  
Minh H. Tran ◽  
Younane N. Abousleiman
Keyword(s):  
Porous Media ◽  
Fluid Pressure ◽  
Transversely Isotropic ◽  
Biological Tissues ◽  
Analytical Models ◽  
Combined Effects ◽  
Saturated Porous Media ◽  
Stress Distributions ◽  
Shale Formations ◽  
Electrically Charged

The porochemoelectroelastic analytical models have been used to describe the response of chemically active and electrically charged saturated porous media such as clay soils, shales, and biological tissues. However, existing studies have ignored the anisotropic nature commonly observed on these porous media. In this work, the anisotropic porochemoelectroelastic theory is presented. Then, the solution for an inclined wellbore drilled in transversely isotropic shale formations subjected to anisotropic far-field stresses with time-dependent down-hole fluid pressure and fluid activity is derived. Numerical examples illustrating the combined effects of porochemoelectroelastic behavior and anisotropy on wellbore responses are also included. The analysis shows that ignoring either the porochemoelectroelastic effects or the formation anisotropy leads to inaccurate prediction of the near-wellbore pore pressure and effective stress distributions. Finally, wellbore responses during a leak-off test conducted soon after drilling are analyzed to demonstrate the versatility of the solution in simulating complex down-hole conditions.

Prediction of the Strength of Ceramic Tubular Components: Part II — Experimental Verification

1991 ◽  
Author(s):  
D. L. Shelleman ◽  
O. M. Jadaan ◽  
J. C. Conway ◽  
J. J. Mecholsky
Keyword(s):  
Silicon Carbide ◽  
Statistical Theory ◽  
Room Temperature ◽  
Strength Distribution ◽  
Ring Test ◽  
Stress Distributions ◽  
Pressure Test ◽  
Tubular Components ◽  
Tubular Specimens ◽  
Strength Distributions

Abstract The strength distribution of reaction bonded silicon carbide tubes that failed by internal pressurization was predicted from strength distributions obtained from simple laboratory test specimens at room temperature. The strength distributions of flexure bars, C-rings tested in tension, C-rings tested in compression, diametrally compressed O-rings, and internally pressurized short tubes were compared to the strength distribution of internally pressurized long tubes. The methodology involved application of Weibull statistical theory using elasticity theory to define the stress distributions in the simple specimens. The flexural specimens did not yield acceptable results, since they were ground prior to testing, thereby altering their flaw population in comparison with the processing induced flaw populations of the tubular specimens. However, the short tube internal pressure test, the c-ring tested in tension and the diametrally compressed o-ring test configurations yielded accurate predictions, since these specimens more accurately represent the strength limiting flaw population in the long tubes.

On the thinning variations in hydrostatic forming of sheet metal

2021 ◽  
Vol 15 (1) ◽  
pp. 7824-7836
Author(s):  
Thu Thi Nguyen ◽  
N.D. Trung
Keyword(s):  
Sheet Metal ◽  
Thickness Distribution ◽  
Input Parameter ◽  
Relative Depth ◽  
Technological Parameters ◽  
Forming Technology ◽  
Input Parameters ◽  
Forming Characteristics ◽  
Cylindrical Cup ◽  
Forming Methods

In sheet metal forming, thinning phenomenon is one of the most concerned topics to ameliorate the final quality of the manufactured parts. The thinning variations depend on many input parameters, such as technological parameters, geometric shape of die, workpiece’s materials, and forming methods. Hydrostatic forming technology is particularly suitable for forming thin-shell products with complex shapes. However, due to the forming characteristics, the thinning variations in this technology are much more intense than in other forming methods. Therefore, in this paper, an empirical study is developed to determine the thinning variations in hydrostatic forming for cylindrical cup. Measurement of thickness at various locations of deformed products are conducted to investigate the thickness distribution and determine the dependence of the largest thinning ratio on the input parameters (including the blank holder pressure, the relative depth of the die and the relative thickness of the workpiece). The results are expressed in charts and equation which allow determining the effect of each input parameter on the largest thinning ratio.

Residual stress in the cylindrical drawing cup of SUS304 stainless steel evaluated by split-ring test

2015 ◽  
Vol 32 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Liang-Hong Xiao ◽  
Dao-He Yuan ◽  
Jun-Zhong Xiang ◽  
Jin-Gang Liu ◽  
Yi-Chun Zhou
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Ring Test ◽  
Split Ring ◽  
Sus304 Stainless Steel

Design of a rotor blade tip for the investigation of dynamic stall in the transonic wind-tunnel Göttingen

2016 ◽  
Vol 120 (1232) ◽  
pp. 1509-1533 ◽  
Author(s):  
B. Lütke ◽  
J. Nuhn ◽  
Y. Govers ◽  
M. Schmidt
Keyword(s):  
Experimental Data ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Numerical Data ◽  
Dynamic Stall ◽  
Navier Stokes ◽  
Fe Model ◽  
Stress Distributions ◽  
Cfd Simulations ◽  
Blade Tip

ABSTRACTThe aerodynamic and structural design of a pitching blade tip with a double-swept planform is presented. The authors demonstrate how high-fidelity finite element (FE) and computational fluid dynamic (CFD) simulations are successfully used in the design phase. Eigenfrequencies, deformation, and stress distributions are evaluated by means of a three-dimensional (3D) FE model. Unsteady Reynolds-averaged Navier-Stokes (RANS) simulations are compared to experimental data for a light dynamic stall case atMa= 0.5,Re= 1.2 × 106. The results show a very good agreement as long as the flow stays attached. Tendencies for the span-wise location of separation are captured. As soon as separation sets in, discrepancies between experimental and numerical data are observed. The experimental data show that for light dynamic stall cases atMa= 0.5, a factor of safety ofFoS= 2.0 is sufficient if the presented simulation methods are used.

scholarly journals Mechanical Behaviour and Springback Study of an Aluminium Alloy in Warm Forming Conditions

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
H. Laurent ◽  
J. Coër ◽  
R. Grèze ◽  
P. Y. Manach ◽  
A. Andrade-Campos ◽  
...  
Keyword(s):  
Mechanical Behaviour ◽  
Tensile Tests ◽  
Warm Forming ◽  
Ring Test ◽  
Punch Force ◽  
Forming Temperature ◽  
Numerical Process ◽  
Forming Condition ◽  
Force Displacement ◽  
Main Factor

This study deals with the mechanical behaviour and material modelling of an AA5754-O alloy at elevated temperature. Experimental shear tests were performed from room temperature up to 200°C, and the material behaviour has been identified with both shear and tensile tests, as a function of temperature. To analyse the influence of temperature during forming over springback, a split-ring test is used. Experimental results are obtained and compared to numerical simulations performed with the finite element in-house code DD3IMP. The numerical process of ring splitting is performed with the in-house code DD3TRIM. The main observed data are force-displacement curves of the punch during forming, cup thickness at the end of forming, and ring gap after splitting. It is shown that all these parameters are strongly dependent on the forming temperature. A correlation is obtained between experimental data and numerical simulation for the evolution of punch force and opening after springback as a function of temperature. The distribution of the tangential stress in the cup wall is the main factor influencing the springback mechanism in warm forming condition.

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