Cup Deep Drawing Research Articles

A study on anisotropic hardening of 7075 aluminum alloy based on non-associated flow rules

The accurate description of anisotropic plastic deformation is key to accurately predicting the stamping forming of metal sheets. The anisotropic yield criterion, when based on the assumption of isotropic hardening, often leads to significant inaccuracies. To address this issue, this paper observes the anisotropic hardening phenomenon through non-associated flow rules and evaluates the anisotropy of 7075-O aluminum alloy. Through a series of tensile tests, we determined the mechanical properties of 7075-O aluminum alloy in three distinct orientations. To describe the metal hardening behavior, we employed the Swift-Voce hardening criterion. From the hardening curves in three different directions, it was found that AA7075-O exhibits plastic anisotropy. Based on the VUMAT subroutine, finite element simulation of AA7075-O tensile tests was conducted through Abaqus. Compared with the Hill48 model, it was found that the simulated values of the S–Y2009 anisotropic hardening model have a higher degree of agreement with the experimental curves. The S–Y2009 anisotropic hardening model was adopted to predict the earing behavior of AA7075-O during circular cup deep drawing. The root mean square error between the predicted values of the S–Y2009 model and the experimental values was only 0.1795, which is far smaller than that of the Hill48 yield model. Therefore, the SY2009 model has important guiding significance for the stamping forming of metal sheets.

Neural network based rYld2004 anisotropic hardening model under non-associated flow rule for BCC and FCC metals

This paper extends the reduced Yld2004 (rYld2004) function to present the anisotropic hardening behavior for body-centered cubic and face-centered cubic metals under the proportional loading conditions based on neural network. The parameters of the rYld2004 anisotropic hardening model (AH_rYld2004) are determined by the uniaxial tensile yield stresses along 0°, 15°, 30°, 45°, 60°, 75° and 90° from the rolling direction as well as equibiaxial tension. The evolution of anisotropic parameters are described by the back propagation neural network optimized by ant colony optimization algorithm. The predicted data by AH_rYld2004 and some common anisotropic models are compared with the experimental results to verify the precision of the AH_rYld2004 in characterizing anisotropic hardening. The comparison proves that the AH_rYld2004 precisely characterize the anisotropic evolution with increasing plastic deformation for AA 3003-O and QP980. Simultaneously, the AH_rYld2004 function based on neural network is used to accurately simulate of circular cup deep drawing for AA 3003-O and uniaxial tension for QP980. The results indicate that the AH_rYld2004 model is capable to accurately represent the plastic anisotropic evolution for uniaxial tension along seven loading directions and equibiaxial tension.

Modeling of Texture Development during Metal Forming Using Finite Element Visco-Plastic Self-Consistent Model

In directional forming processes, such as rolling and extrusion, the grains can develop preferred crystal orientations. These preferred orientations—the texture—are the main cause for material anisotropy. This anisotropy leads to phenomena such as earing, which occur during further forming processes, e.g., during the deep drawing of sheet metal. Considering anisotropic properties in numerical simulations allows us to investigate the effects of texture-dependent defects in forming processes and the development of possible solutions. Purely phenomenological models for modeling anisotropy work by fitting material parameters or applying measured anisotropy properties to all elements of the part, which remain constant over the duration of the simulation. In contrast, crystal plasticity methods, such as the visco-plastic self-consistent (VPSC) model, provide a deeper insight into the development of the material microstructure. By experimentally measuring the initial texture and using it as an initial condition for the simulations, it is possible to predict the evolution of the microstructure and the resulting effect on the mechanical properties during forming operations. The results of the simulations with the VPSC model show a good agreement with corresponding compression tests and the earing phenomenon, which is typical for cup deep drawing.

The Square cup deep drawing: Technology transfer from experts to increase production in small and medium enterprise (SME) groups

The deep drawing is a complex steel forming method involving blank dimensions, dimension/height ratio (D/H ratio), and clearance between die and punch (D/P allowance). Failure to identify proper blank dimensions and D/H ratio can lead to production defects such as tears, while failure to recognize the correct clearance can cause wrinkles. This article discusses technology dissemination to Small and medium-sized enterprises (SMEs) for the deep drawing process in producing R-ornament components #3D40x40, considering these crucial parameters. R-ornament #3D40x40 was manufactured using SPCC-SD material with a thickness of 0.65 mm. The Participatory Action Research (PAR) method was employed to collaboratively optimize blank dimensions, D/H ratio, and dies/punch (D/P) allowance with partners. The optimization of blank dimensions successfully eliminated the need for the trimming process, resulting in reduced investment costs in dies and die setup by IDR 15 million and 2.16 million, respectively. Identifying a D/H ratio of 1.32 successfully eliminated tear defects and determining a D/P allowance of 0.87 mm on each side eradicated wrinkle defects in the product. This article contributes to Goal 9 of the Sustainable Development Goals (SDGs), specifically focusing on the Small and Medium-sized Enterprises (SMEs) sector.

Optimization and Modelling of Fracture Height in SECC Cylindrical Cup Deep Drawing Processes

Optimization and Modelling of Fracture Height in SECC Cylindrical Cup Deep Drawing Processes

Analysis and Experiment of Blank Holder Gap in the Cylindrical Cup Deep Drawing of Low Carbon Steel to Prevent Cracking-Wrinkling

This paper aims to investigate Blank Holder Gap (BHG) in order to prevent wrinkles and crack defects in the deep drawing process of cylindrical cups with a diameter of 30 mm, using low carbon steel grade SPCC that is 0.7 mm thick. Mathematical and experimental approaches were applied to study the effect of BHG on wrinkle wave height and product quality. The analytical approaches used were the slab method and the Forming Limit Diagram (FLD) to determine the final thickness of the product specimen and the height of the wrinkling wave, respectively. Each method in this study had been compared to each other. Punch-die dimensions were determined based on the standard tool designed. According to the research, BHG is set 100% to 114% of the thickness of the initial material or equivalent about 0.70 to 0.80 mm. By using the value of this gap, the height of wrinkles can be avoided, the magnitude of the drawing force is still below the critical limit, and the product specimen does not experience wrinkles and cracks. The results of this study are applicable to the deep drawing of cup products on SPCC material with a thickness of no more than 1 mm.

Multi-scale numerical investigation of deep drawing of 6K21 aluminum alloy by crystal plasticity and a stress-invariant based anisotropic yield function under non-associated flow rule

In this research, the earing characteristics of 6K21 aluminum alloy in circular cup deep drawing are investigated by virtue of experiments and multi-scale simulations including anisotropic Drucker, Hill48, Yld91 yield functions and crystal plastic finite element model (CPFEM). First, the deep drawing experiments of AA 6K21 are carried out to explore the influences of blank holding force (BHF) and blank diameter (BD) on earing profile and mechanical response. The user-defined material model subroutine is written for LS-DYNA explicit code, including constitutive model and ductile fracture criterion under associated or non-associated flow rule (NAFR). The parameters of the crystal plasticity model are calibrated by means of an optimization algorithm. Three yield functions under NAFR and CPFEM are used to predict earing in deep drawing simulation. The effects of five textures on the earing profiles and thickness variables are studied by CPFEM. The results demonstrate that the earing rate decreases slightly as the BHF increases. However, the mechanical response changes insignificantly. Moreover, as the BD increases, both the earing rate and mechanical response increase significantly. Considering computation accuracy and efficiency, the anisotropic Drucker function can accurately character the plastic deformation behavior of deep drawing. For five textures in CPFEM, Cube and Goss textures produce four ears at 0o and 90o from the rolling direction. Brass and S textures form six ears at 0o and 55o. Copper texture fabricates eight ears at 40o and 70o. The influences of five textures on earing rate are Goss > Cube > Copper > Brass > S. Furthermore, there are obvious thickness gradient fluctuations at the corner of the cup in Cube, Goss and Copper textures. It is expected to reduce the earing rate and improve the formability through reasonable allocations of experimental parameters and texture proportions.

Inhibition of adhesive wear in tantalum cup deep drawing by ultrasonic vibration–assisted forming technology

Inhibition of adhesive wear in tantalum cup deep drawing by ultrasonic vibration–assisted forming technology

Hybrid optimisation of input process parameters of deep-drawn cylindrical cups from directional rolled copper strips

Deep drawing is a method of producing sheet metal. It is extensively used in the automobile, packaging and home appliance industries. Incorrect parameter selection might induce defects in stamped components. Trial and error can improve product accuracy, but at the expense of execution and calculation. An optimisation approach and a response surface model are used to determine the optimal parametric parameter design. This study proposes a full and efficient optimisation approach, starting with modelling by RSM (Response Surface Methodology) and concluding with optimal process parameter identification. Based on this, a neural network was developed to improve cylindrical cup deep drawing. Three characteristics of fabricating the cups are clearance, punch radius and coefficient of friction. This parameter demonstrates the resultant tool force, spring back, maximum forming limiting curve and maximum thinning rate of cylinder cups. Initially, the three inputs are varied to measure the outcome using simulation software by Altair inspire form. Then, the equations for each output are designed using quadratic-based linear model fitting. The generated objective function is then used to establish the ideal process parameters for the cylindrical cups. The proposed method is compared to real-time physical experiments. The optimised parameter microstructure at the high-stress zone and the product quality are satisfactory without defects.

Numerical simulation of sheet metal forming of an Al-Mg alloy incorporating plane strain properties in the yield criterion

In this work, numerical simulation of AA5083-O aluminum alloy sheets is carried out using Yld2000-2d yield criterion to predict thinning and variation of load with displacement in sheet metal forming. It has been found that the accuracy of predictions in numerical simulation depends on the coefficients and the stress exponent used in the yield criterion. Hydraulic bulge tests with circular and elliptical die cavities are performed to characterize the material in equi-biaxial and plane strain conditions. An improved stress exponent is determined by incorporating the material properties obtained in plane strain in the existing criterion. The improved stress exponent is validated by using it in the numerical simulations of cylindrical cup deep drawing and stretch forming at room temperature. The same exponent is also used in the numerical simulations carried out for the case of experiments conducted at 250°C. The predicted thinning and load-displacement variations from the numerical simulations are validated with the experimental measurements. A considerable improvement in the results predicted using the improved stress exponent is observed at both the temperatures.

Measuring Deformation of Deep Drawing of Various Alloys by Image Processing Using Matlab

Measuring deformation mostly is based on the contact type of measurements which utilize the gauges and instruments. But this type of contact will lead to error in the precise measurement because of errors by the contact, measuring instruments, and human. So, feel proud to introduce image processing in the field of measurement. Here, in this study deals the measurement of deformation of deep drawing specimen by image processing which is called as contact free method. This is invasive method of measurement in two dimensions.Deep drawing process is an important sheet metal forming in which flat sheet metal had been forced through the die in association with the forward punch force and opposing blank holder force. As the blank passes through the tool set converts 2D bank into 3D cup formation. The process of achieving the required diameter of the cup can be produced in single stage or multistage operation. In this study, experimental study had been conducted on single stage deep drawing process for assessment of deformation and strain in aluminum alloy, copper alloy and brass alloy. Cylindrical cup deep drawing experimental tests were performed with blank of 60 x 60 square plate with 1 mm thickness. Eventually this new approach will help to optimize the geometry parameters deep drawing specimen correlation with the Matlab results.

Optimization of process parameters for rectangular cup deep drawing by the Taguchi method and genetic algorithm

Abstract This article presents the optimization of process parameters in reducing the risk of failure due to wrinkling and fracture in deep drawing of a rectangular cup. Blank holder force, friction coefficient, punch radius and initial blank shape were chosen as design parameters. Wrinkling and fracture criteria were used as objective functions. Two-stage optimization approach was used. In the first stage optimization, optimum blank shape was determined using the Taguchi optimization method. In the second stage optimization, optimum parameter values were determined for the selected blank shape by the first stage optimization using genetic algorithm. In the second stage of optimization, response surface models based on 3-level full factorial design of experiments were constructed. Finite element simulation results were used for creating response surface models. Parameters obtained from optimization study were confirmed by conducting deep drawing simulations using commercial code DYNAFORM 5.9.2. Optimum results showed that proposed optimization methodology can solve wrinkling and fracture problems in the sheet metal forming process.

A simple and computationally efficient stress integration scheme based on numerical approximation of the yield function gradients: Application to advanced yield criteria

In this paper, we have modified the stress integration scheme proposed by Choi and Yoon [1]; which is based on the numerical approximation of the yield function gradients, to implement in the finite element code ABAQUS three elastic isotropic, plastic anisotropic constitutive models with yielding described by Yld2004-18p [2], CPB06ex2 [3] and Yld2011-27p [4] criteria, respectively. We have developed both VUMAT and UMAT subroutines for the three constitutive models, and have carried out cylindrical cup deep drawing test simulations and calculations of dynamic necking localization under plane strain tension, using explicit and implicit analyses. An original feature of this paper is that these finite element simulations are systematically compared with additional calculations performed using (i) the numerical approximation scheme developed by Choi and Yoon [1]; and (ii) the analytical computation of the first and second order yield functions gradients. This comparison has shown that the numerical approximation of the yield function gradients proposed in this paper facilitates the implementation of the constitutive models, and in the case of the implicit analyses, it leads to a significant decrease of the computational time without impairing the accuracy of the finite element results. In addition, we have demonstrated that there is a critical loading rate below which the dynamic implicit analyses are computationally more efficient than the explicit calculations.

A Spline Shape Deep Drawing using Finite Element Simulation and Experimental Work Test

In the current research, an analysis study was conducted to process of design of spline cup drawing. Deep-drawing tools (dies and punches) were designed and manufactured to implement the experimental work required to produce a spline cup with inner dimensions are height h=3 mm, width W=9.64 mm, and diameter d=34 mm, drawn from a circular blank of a di ameter D b = 8 0 mm, and thicknes s t = 0 . 7 mm made of low carbon steel (1008-AISI). To simulate the spline shape deep-drawing process, a commercial finite element program code ANSYS 19.0 Workbench was employed. The research aims to produce the spline shape and study the effect of the punch wall curvature radius on the drawing force, thickness distribution, and effective strains across the sidewall, major and minor axis curvature of a completely drawn spline cup using experimental testing and finite element modeling. From the comparisons between the experimental and finite element results, it was shown that the numerical results of a spline cup deep-drawing are good agreement with the results of the experiment and lie within an average of (4% - 8%). The drawing force and thinning for the small punch wall curvature radius is higher than the large punch wall curvature radius. The maximum drawing force and maximum thinning with the smallest punch wall curvature radius (0.5) at the minor axis curvature of a completely drawn spline cup. The maximum effective strain with the smallest punch wall curvature radius (0.5) at the minor axis curvature region at the completely drawn spline cup rim.

Failure prediction of magnesium alloys based on improved CDM model

The aim of this contribution is to improve the behavior and failure prediction accuracy for magnesium alloy sheet forming simulation by using advanced fully coupled Continuum Damage Mechanics (CDM) model. Starting from known fully coupled constitutive equations at large inelastic (plastic or viscoplastic) strains, three aspects are enhanced on the CDM model developed by Saanouni (2012). The first one concerns the accurate description of tension-compression asymmetry in yielding and hardening of magnesium alloys induced by combined slip and twinning deformations. The second concerns introducing the stress state dependence in damage evolution to improve the fracture prediction under various loading paths. The third deals with temperature and strain rate (viscosity) effects for metal forming processes at elevated temperatures. The improved fully coupled constitutive equations were implemented into finite element code ABAQUS/Explicit via user subroutine VUMAT including the specific local integration scheme to compute the state variables at each quadrature point. Various kinds of tensile tests at different temperatures and strain rates are used to determine the material parameters, and the complete identification procedure is given in details. As validation, the improved model is applied to simulate the three-point bending and circular cup deep drawing tests, the predicted results show good agreements with the experimental observations.

Investigation of deep drawing of lightweight bimetallic Al1050/SS304 sandwich composite cup

The effect of geometrical and process parameters on the deep drawing behavior of Aluminium (Al1050)/Steel (SS304) bimetallic axis-symmetric sandwich composite cup is analyzed by using numerical and experimental approaches. The parameters are selected focusing on the elimination of defects like thinning, thickening, tearing, and wrinkling. The explicit deep drawing analysis of the cylindrical cup is carried out by using the finite element software package. The obtained numerical results are utilized for the optimization and identification of significantly influencing parameters using Taguchi and ANOVA techniques and further validated by performing an experimental test. The effectiveness in the utilization of the Al1050/SS304 sandwich composite sheet for deep drawing of cups is proved by comparing it with the deep drawing of the SS304 sheet. The results suggest that the sandwich composite cup under investigation can be drawn successfully with the higher limiting drawing ratio and low thickness variation. The obtained maximum limiting drawing ratio (2.08) showed that the higher formability of the Al1050/SS304 sandwich composite sheet is possible by a sandwich of the SS304 sheet with an Al1050 sheet.

Using the artificial neural network to investigate the effect of parameters in square cup deep drawing of aluminum-steel laminated sheets

In this study, the effective parameters involved in the deep drawing of double-layer metal sheets in a die ofsquare cross-section were investigated through artificial neural network (ANN) modeling. For this purpose,first, the deep drawing of double-layer (Al1200 / ST14) sheets was carried out experimentally. Also, the finiteelement simulation of the process was performed, and the results validated through experimental tests. A setof 46 different experimental data were employed in this paper. The ANN was trained by using a mean squareerror of 10-4. The input parameters, i.e., punch radius, die radius, blank holder force, clearance, and the permutationlayers were set to the network. The surface response method (RSM); was employed to evaluate theresults of the ANN model, and the input parameters of the deep drawing process on the thinning of Al1200and ST14 composite layers were analyzed. The obtained results indicate that the punch edge radius has themost significant influence on the thinning of the Al1200 layer. Increasing the gap between the punch and dieto 1/4 of the sheet thickness, increased the cup wall layers thickness of the Al1200 and ST14 respectively by3.38% and 0.5%. The performance of the ANN model demonstrates that it can estimate the amount of thinningin the composite layers with satisfactory accuracy.

Prediction on the Mechanical and Forming Behaviors of Ferrite-Martensite Dual Phase Steels Based on a Flow Model

An innovative flow model incorporating the mixture hardening law, anisotropic yield function, and incremental strain formulations was elaborated and applied to DP590 ferrite-martensite dual phase steel. To verify the flow model, both the macro/micro stress-strain responses and the forming patterns of DP590 steel with different martentite contents were simulated during the processes of the cup deep-drawing and the unconstrained cylindrical bending to evaluate the influence of martensite content on the mechanical and forming behavior of the steel. It was found that maternsite content has a significant impact on the macro/micromechanical and forming behavior of the steel, i.e., the ferrite and steel effective stresses and the effective macro/micro-strain distribution in the cup. Under the unconstrained cylindrical bending, the simulated effective maximum macro/micro-strains were in good agreement with the calculated results from the mixture law-based model. It was concluded that the Buaschinger effect is the main reason for an 8 % error between the simulated and experimental results. The flow model was proved to predict the macro/micro flow and forming behavior of the dual phase steels with a good accuracy.

Wrinkling Prediction of Rectangular Cup Deep Drawing Process for Aluminum Alloy Sheets by Using the Modified Yoshida Buckling Test

Nowadays, the industry has been growing interest in lightweight material for automotive and cookware manufacturing. The formability of sheet material is an important issue in these industries. The wrinkling behavior is one of the most failure in sheet metal forming and is often occurred in deep drawing process in cookware manufacturing. In this work, the developed wrinkling limit curves (WLCs) using experimental and numerical simulation of a modified Yoshida buckling test were precisely used to predict the wrinkling behavior of rectangular cup deep drawing for aluminum alloy sheets grade AA5054-O and AA5052-H32. The Industrial parts, the rectangular cup deep drawing was firstly performed for both investigated aluminum sheets for obtaining the wrinkling initiation on the side wall area of deep drawing parts. Subsequently, the experimental formed parts were carefully measured the draw-in of deformed blank sheets and drawing depth to validate the finite element (FE) model. Then, the FE simulation of the corresponding drawing tests were calculated, by which were implemented with the Hill’48 yield criterion and Swift hardening law to descript anisotropic plastic deformation. As a result, the local principle Major and Minor principle strains of observed wrinkle areas were gathered in the side wall area of the rectangular cup deep drawing test. Finally, the developed WLCs of aluminum alloy sheets were applied to predict the wrinkling formation of the formed deep drawing parts. Comparatively, the influence of different aluminum alloy grades on the WLCs and wrinkling behavior were explicitly investigated.

Fracture envelopes on the 3D-DIC and hybrid inverse methods considering loading history

This paper deals with the comparative investigation of fracture envelopes constructed by the 3D-DIC and hybrid inverse analyses. For the evaluation of fracture limits of the DP980 1.2t steel over a wide range of loading conditions, tensile tests were conducted using three different specimens that are expected to induce certain stress states of plane strain tension, in-plane shear, and uniaxial tension at the potential location for the fracture initiation. The modified Mohr–Coulomb ductile fracture criterion was selected in this study to investigate the influence of the fracture envelope identification based on each way of loading history evaluation not only on the level of fracture limits but also on the fracture prediction especially for the simulation of square cup deep drawing. For an in-depth understanding of non-linear loading history on the variation of ductility limit, apparent fracture with respect to strain was numerically computed according to the change of loading path. Finally, a comparison of results from the square cup deep drawing test and the FEA prediction was performed in terms of punch force and stroke to confirm the model performance at various ways of the loading history evaluation.