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Formability analysis of an Aluminium panel. a Shape of Al-panel, b results of formability calculation
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![Fig. 1: Material modelling in AutoForm [6]](publication/322946593/figure/fig1/AS:590845287874562@1517879902398/Material-modelling-in-AutoForm-6_Q320.jpg)
Sheet metal forming is widely used in automotive, aviation, packaging, and household goods. It is most popular for the manifold technical feasibilities in manufacturing, high precision, mass production, and short processing time. Modern automotive concepts demand a weight reduction by using high strength materials and excellent crash performance, w...
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... formability analysis is performed by multiple iterations using sigma optimisation simulations. Fig. 2 shows the dif- ferent zone of the FLD and corresponding areas. 95.18% of the elements are under the safe zone, 2.25% of elements are under the compression, 1.81% of elements are under the in- sufficient stretch, and 0.74% of elements are under excess thinning zone in the FLD. These results show that the deep drawing process designed ...
Similar publications
The quality of sheet metal formed parts is strongly dependent on the tribology and friction conditions that are acting in the actual forming process. These friction conditions are then dependent on the tribology system, i.e. the applied sheet material, coating and tooling material, the lubrication and process conditions. Although friction is of key...
Deep drawing is one of the most common sheet metal forming processes. It is largely used for mass production of parts in various shapes in automobile, packaging, and household appliance industries. During this process, the stamped part is susceptible to the process failures, especially springback if the process parameters are not correctly selected...
Citations
... Thus, as the strength of the material increases, the springback values increase. In addition, after the bending process of sheet materials is completed, the deformation and fracture behaviour should be known [23], [42]. Leu emphasized the formability properties of dual-phase sheets in her study, in which she examined the deformation behaviour of high-strength sheets. ...
... In sheet metal forming applications, an accurate representation of the material's plastic behavior is crucial for obtaining reliable results in finite element simulations [118]. The accuracy of finite element simulation strongly depends on the extent to which a material constitutive model can characterize the real material properties [119]. ...
This paper presents a review on the formability evaluation of AHSS, enhancing necking-based failure criteria limitations. Complementary fracture/damage constitutive modeling approaches specifically tailored to formability evaluation, validated through numerical and experimental methods, are also subjects of research. AHSS are widely processed through sheet metal forming processes. Although an excellent choice when lightweight, high-strength, and ductility are critical factors, their multi-phase microstructure accentuates forming challenges. To accurately model forming behavior, necking-based failure criteria as well as direct fracture models require improvements. As a necking-based failure model, the conventional forming limit diagram/curve (FLD/FLC) presents limitations in estimating direct fracture (surface cracks, edge cracks, shear cracks), as well as deformation histories under non-linear strain paths. Thus, significant research efforts are being made towards the development of advanced fracture constitutive models capable of predicting fracture scenarios without necking, which are more frequently observed in the realm of AHSS. Scientific community research is divided into several directions aiming at improving the forming and fracture behavior accuracy of parts subjected to sheet metal forming operations. In this review paper, a comprehensive overview of ductile fracture modeling is presented. Firstly, the limitations of FLD/FLC in modeling fracture behavior in sheet metal forming operations are studied, followed by recent trends in constitutive material modeling. Afterwards, advancements in material characterization methods to cover a broad range of stress states are discussed. Finally, damage and fracture models predicting failure in AHSS are investigated. This review paper supplies relevant information on the current issues the sheet metal forming community is challenged with due to the trend towards AHSS employment in the automotive industry.
... Friction and wear of forming dies have been the topic of interest for many researchers around the world. [3][4][5] Severe friction is encountered due to the sliding of blank and die in the die shoulder radius region. Oil lubrication often improves the interaction with friction circumstances in the dieblank and blank-blank holder interface. ...
This research proposes a complete analysis of the use of physical vapour deposition coated dies in the sheet metal forming process for high‐strength‐steel sheets. The goal of the proposed approach is to investigate how PVD coatings affect die performance and how that affects the formability and quality of the high‐strength‐steel‐sheets that are made. The finite element analyses are used to simulate and evaluate the mechanical behaviour and deformation characteristics during the forming process. Studies to enhance the forming characteristics of these materials, typically denoted by limiting draw ratio and maximum punch force are required. A reduction in punch force required and improved limiting draw ratio is observed that is attributed to the enhanced contact with friction‐conditions in the die‐sheet interfaces. The experimental results are compared with simulation results from DD3IMP, a code used for deep drawing simulations, and it is evident that the experimental outcomes are analysed well with the simulation results.
... In sheet metal forming applications, an accurate representation of the material's plastic behavior is crucial for obtaining reliable results in finite element simulations [106]. The accuracy of finite element simulation strongly depends on the extent to which a material constitutive model can characterize the real material properties [107]. ...
This paper presents a review on numerical and experimental methods to predict fracture of ad-vanced high strength steels (AHSS). AHSS are widely processed through sheet metal forming processes. Although being an excellent choice when lightweight, high strength and ductility are critical factors, their multi-phase microstructure accentuates forming challenges. To accurately model forming behavior, necking based failure criteria as well as direct fracture models require improvements. As a necking based failure model, the conventional forming limit diagram/curve (FLD/FLC) presents limitations such as in estimating direct fracture (surface cracks, edge cracks, shear cracks), as well as deformation histories under nonlinear strain paths. Thus, significant re-search efforts are being made towards the needs of advanced fracture constitutive models capa-ble of predicting fracture scenarios without necking, more frequently observed in the realm of AHSS. Scientific community research is divided into several directions aiming at improving the forming and fracture behavior accuracy of parts subjected to sheet metal forming operations. In this review paper, a comprehensive overview on ductile fracture modeling is presented. Firstly, the FLD/FLC limitations modeling fracture behavior in sheet metal forming operations are stud-ied. Followed by the recent trends in constitutive material modeling. Afterwards, material char-acterization methods advancements to cover a broad range of stress states are comprised. Final-ly, damage and fracture models predicting failure in AHSS are investigated. This review paper supplies relevant information on the current issues the sheet metal forming community is chal-lenged with due to the trend towards AHSS employment in the automotive industry.
... Such simulations were successfully validated during experimental tests by subsequent comparison of the stressstrain curves obtained by using the new method proposed by the authors and state-of-the-art methods. Jadhav et al. [5] presented applications of finite element simulation in the development of advanced sheet metal forming processes during which two different blanks of 22MnB5 with 1.5 mm and 1.6 mm thickness were used to manufacture a B-pillar. The authors highlighted, that the friction condition affects the surface quality of the product, tooling life, efficiency, and stability of processes [5]. ...
... Jadhav et al. [5] presented applications of finite element simulation in the development of advanced sheet metal forming processes during which two different blanks of 22MnB5 with 1.5 mm and 1.6 mm thickness were used to manufacture a B-pillar. The authors highlighted, that the friction condition affects the surface quality of the product, tooling life, efficiency, and stability of processes [5]. Ayllon et al. [6] developed a compression test system with load application in the in-plane sheet directions, which was calibrated using finite element simulations. ...
Background
The modelling of the sheet metal forming operations requires accurate and precise data of the material plastic behaviour along non-proportional strain paths. However, the buckling phenomenon severely limits the compressive strain range that could be used to deform thin metal sheets.
Objective
The main aim of this paper was to propose an effective device, that enables to determine of accurate stress-strain characteristics of thin metal sheet specimens subjected to axial deformation without buckling and with a special emphasis on friction correction.
Methods
In this paper, an anti-buckling fixture was proposed to assess the deformation characteristics of X10CrMoVNb9-1 (P91) power engineering steel, and DP500 and DP980 dual-phase steels, under compression loading. The fixture enables monitoring of the friction between the specimen and supporting blocks during the test, and thus the precise stress response of the material could be determined.
Results
The effectiveness of the fixture was evaluated under tension–compression cyclic loading and during the compression tests in which high-strength thin metal sheets were successfully deformed up to 10% without specimen buckling. Furthermore, the successful determination of a friction force variation between supporting blocks and the specimen during tests enabled to determine an actual force acting on the specimen.
Conclusions
The proposed testing fixture was successfully assessed during the compression and cyclic tension–compression of high-strength thin metal sheets as no buckling was observed. Its advantage lies in adapting to change its length with specimen elongation or shrinkage during a test. The friction force generated from a movement of both parts of the device could be effectively monitored by the special strain gauge system during testing and thus its impact on the stress-strain characteristics could be successfully eliminated.
... [73][74][75] Out of these two methods, the finite element method is more popular for numerical simulation of complex sheet metal forming processes. [76][77][78][79][80] A variety of defects and complexities involved in sheet metal forming processes were predicted for improving the quality of sheet metal parts before actually forming. [81][82][83] With the advent of highspeed micro-processors and high-end computational facilities, nowadays it is easier to do accurate FEM simulation of sheet metal forming processes. ...
Flanging is sheet metal forming process which has high-end applications from automobile industry to aircraft industry. Straight, stretch, shrink and hole-flanging are the variations of flanging process flange types. It is found that that market share (revenue) of flanging process in stamping industry will increase by nearly 4 billion USD during the decade of 2013–2024. Coventional stamping, incremental forming, rubber forming, fluid forming, electromagnetic forming are the technologies utilized till date for the formation of flanges. Hole-flanging is the most widely used/applied form of flanging process. Besides this, shrink flanging process finds its applications in automobile and aircraft parts. The objective of the present study deals with critical review and analysis of sheet metal shrink flanging process. Aluminum alloys were used for manufacturing aircraft parts, whereas steel alloys were used for manufacturing car body parts in the making shrink flanged parts. Strain-based models were majorly used in mathematical analysis of shrink flanging process. Shell-based elements were utilized for meshing of sheet metal for FEM analysis of shrink flanging process. Rubber forming was found to be most efficient forming technique for the formation of shrink flange portion parts. Blank shape optimization is carried out by employing FEM simulation topology optimization for shrink flanging process.
... To validate the values found experimentally, to confirm or deny the influence of various parameters and to be able to understand the behavior of the material, software simulation finite element simulation software is used [4] such as ABAQUS software. ...
The stamping process of the sheets requires the determination of the mechanical characteristics of the latter as well as its behavior. In this study, we developed a procedure to identify the effect of temperature in the cutting operation on the behavior of the sheet. This procedure is based on conventional tensile tests on the specimens, in cold-rolled sheet called DC01. They are cut in different orientations depending on the direction of rolling and with two different processes. We use laser cutting and robot wire cutting. The analysis of the tensile tests therefore makes it possible to determine the parameters related to the anisotropy of the sheet and the impact of temperature on the mechanical characteristics of the material.
... Hence it is an important factor for the deep drawing process. A high r-value provides better formability with less thinning of sheet metal [22]. Similarly, Tisza and Kovács [23] reported that higher anisotropy coefficient provides more favorable limit strain values especially for negative range of minor principal strain. ...
A Sheet Metal Forming (SMF) process, especially deep drawing, is one of the manufacturing
processes that commonly used in the automotive industry. Compared with casting and forging, the SMF process
has several advantages, including lesser weight materials and broader variations in shape that can be made. The
most important of the problems in the SMF process is the wrinkling phenomenon and tearing of sheet products.
The wrinkle and tear occurs because of the mechanical properties of the material, product geometry, and blank
holder force. The finite element based Computer-Aided Engineering (CAE) program AutoForm Plus R7 used
in this article was used for analysis. Solidworks software was used during mold design. AutoForm is a highly
productive software that provides high accuracy and reliable results, specially developed for the sheet metal
forming mold industry, especially for the automotive industry. With AutoForm, multiple analyses were made
by computational calculations, even before the mold production started, and with the help of these analyses, the
closest to perfect mold outputs were obtained. In addition, optimum drawbead geometry and springback effect
were analysed. The most suitable material was selected for the deep drawing product. DX54D + Z and DX56D
+ Z from continuously hot-dip coated steel flat products selected as analysis materials. As a result, the simulation
reports obtained from this study were compared with many results in the literature. It is concluded that DX56D
+ Z sheet material can be used in deep drawing products without negative consequences such as tearing,
wrinkling and shrinkage marks.
... Hence it is an important factor for the deep drawing process. A high r-value provides better formability with less thinning of sheet metal [22]. Similarly, Tisza and Kovács [23] reported that higher anisotropy coefficient provides more favorable limit strain values especially for negative range of minor principal strain. ...
... In order to mitigate the effects of uncertainty in stamping processes, since the early 1990s, there has been a significant increase in the use of simulations by finite element (FE) methods to sheet conformation in industry [17][18][19]. For example, FE simulations are useful for reducing lead time in the design and tool development stage, as pointed out by [20]. ...
The response surface methodology (RSM), which uses a quadratic empirical function as an approximation to the original function and allows the identification of relationships between independent variables xi and dependent variables ys associated with multiple responses, stands out. The main contribution of the present study is to propose an innovative procedure for the optimization of experimental problems with multiple responses, which considers the insertion of uncertainties in the coefficients of the obtained empirical functions in order to adequately represent real situations. This new procedure, which combines RSM with the finite element (FE) method and the Monte Carlo simulation optimization (OvMCS), was applied to a real stamping process of a Brazilian multinational automotive company. For RSM with multiple responses, were compared the results obtained using the agglutination methods: compromise programming, desirability function (DF), and the modified desirability function (MDF). The functions were optimized by applying the generalized reduced gradient (GRG) algorithm, which is a classic procedure widely adopted in this type of experimental problem, without the uncertainty in the coefficients of independent factors. The advantages offered by this innovative procedure are presented and discussed, as well as the statistical validation of its results. It can be highlighted, for example, that the proposed procedure reduces, and sometimes eliminates, the need for additional confirmation experiments, as well as a better adjustment of factor values and response variable values when comparing to the results of RSM with classic multiple responses. The new proposed procedure added relevant and useful information to the managers responsible for the studied stamping process. Moreover, the proposed procedure facilitates the improvement of the process, with lower associated costs.
