Sheet Metal Forming Processes Research Articles

Performance Analysis of Multi-Point Incremental Forming Tool using Martensitic AISI 420 Sheet Metals

Incremental Sheet metal Forming (ISF) Process is a suitable process which helps to produce various parts used in automotive sector by rapid prototyping. This method of producing a prototype helps industry in reducing the production cost. In ISF process, a final product is evolved through local deformation of the sheet metal made by the tool. Usually better formability is obtained when the tool makes a better contact with the sheet metal throughout the process. Improved formability elevates dimensional accuracy of the product, thus increases the market value of the product. A new tool with multiple ball ends capable of making multiple mating points over sheet metal was used in this research to enhance the efficiency of formability and surface finish. Ability of the new Multi-Point Incremental Forming Tool (MPIF) was investigated and compared to the existing Single Point Forming Tool (SPIF) based on the formability and surface finish. Forming Limit Diagram (FLD), Strain Distribution (SD) and Scanning Electron Microscope (SEM) were used to examine the formability of the sheet metal. The SEM & 3D-Surface roughness profilometer were used to observe the sheet metals surface finish. In addition to these experimental techniques a simulation results were also used to predict the stress and strain rate during forming process. The experimentation and simulation outcome shows that the MPIF provides superior formability and surface finish.

Sheet-Metal Forming Processes with Local Plastic Deformation by using Conventional Spinning Methods - Introduction

Sheet-Metal Forming Processes with Local Plastic Deformation by using Conventional Spinning Methods - Introduction

Approaches for Preventing Tool Wear in Sheet Metal Forming Processes

Sheet metal forming processes, the purpose of which is to give the shaped material appropriate mechanical, dimensional and shape properties, are characterised by different values of unit pressures and lubrication conditions. Increasing the efficiency of tool work by increasing their durability, efficiency and reliability is still one of the main indicators of increasing production efficiency. Tool wear in metal forming technologies significantly differs from the character of wear in other methods of metalworking, such as machining. This article presents the characteristics of tool wear mechanisms used in sheet metal forming. Possibilities of increasing the durability of tools by applying coatings produced by laser techniques, chemical vapour deposition and chemical vapour deposition are also discussed. Great emphasis is placed on self-lubricating and functional materials and coatings. Current trends in lubricants and lubrication methods in sheet forming, including tool texturing, are also presented.

Numerical Modelling and Simulation of Sheet Metal Forming Process

Simulation and modelling of sheet metal forming process are well common today in different industries (automotive, aerospace) and several research centers regarding its huge impact for both on production and reliability of the lifecycle of the equipment, and the quality of the product. However, to obtain the best configuration possible with the inputs parameters to achieve high level of production and increasing the durability of the tools needs some extra methods for the optimization for this problem using mostly finite element method cooperated with iterative algorithms based on Artificial Neural Network (ANN) [1]. Whereas this research is focused on modelling of stamping process of stainless steel AISI 304 to investigate to formability of the material, and studying the influence of the friction factor on the quality of the product as well the energy required for each set configuration.

Literature Review on Analysis of Spring Back in Sheet Metal Forming Processes

Abstract: The spring back is the part of sheet metal bending that is most susceptible to failure during unbounding. Elastic and plastic deformation combine to completely distort the workpiece (sheet metal) during the metalworking process. When sheet metal is being worked on, it is put under a lot of pressure, which causes plastic deformation. However, when the pressure is released, the material recovers elastically. During the entire process. small amount of reduction in the total deformation takes place So, this phenomenon. is called as spring back-the change in sheet metal's geometry. The thickness of sheet metal ranges from 0.5 mm to 6 mm. Depending on the tooling geometry, material qualities, sheet thickness, and punch and die properties, spring back can affect the completed part's dimensional accuracy. Sheet metal elements / materials / appliances made in industries such as automotive OEM and ancillaries, enclosures aircraft, heavy machinery, medical devices etc. are affected by spring back in their correctness. This review study examines various factors influencing springback in sheet metal fabrication

The Use of Non-Edible Green Oils to Lubricate DC04 Steel Sheets in Sheet Metal Forming Process

Lubrication is a basic and relatively effective way to reduce friction in sheet metal forming operations. The drive to eliminate synthetic and mineral oils, which are difficult to recycle, from the manufacturing process has opened up opportunities for the use of vegetable-based bio-lubricants. This article presents a comparison of the lubrication performance of two non-edible oils (karanja and moringa) with the most frequently tested edible oils (sunflower and rape-seed). Deep drawing quality low-carbon steel sheets DC04, commonly used in the automotive industry, were used as the test material. Friction tests were carried out under various lubricants and normal pressures in the range between 3 and 12 MPa using the strip drawing test. Furthermore, a study was also made of the effect of a change in the surface topography and the mechanical properties of the sheet metal due to plastic deformation resulting from friction. It was found that under the most favorable lubrication conditions (sample pre-strain 21%, nominal pressure 6 MPa), karanja oil reduced the coefficient of friction by approximately 33%. Both non-edible lubricants provided the best lubrication when testing samples pre-strained at 7% under the whole range of nominal pressures. It was also revealed that in the case of the smallest pre-straining of the specimens (7%), karanja oil was the most effective within nominal pressures of 3–6 MPa, while at higher pressures (9–12 MPa), the moringa oil lowered the value of the coefficient of friction to a greater extent.

A Review on Design of Additively Manufactured 3D Printed Tools for Sheet Metal Forming Processes

The additive manufacturing technology is progressing at a faster rate than any other manufacturing process, as it influences the process innovatively and facilitates customize products and iterative design, which help the production system to achieve a higher goal. Further, rapid prototyping like the 3D printing process is now being the alternative support system for traditional manufacturing. The industries are relying on rapid prototyping, which is now a key factor in competitive leading market conditions. Due to the growing interest, industries such as sheet metal forming, aerospace, automotive, healthcare, electronics, food, fashion, and retail are adopting this technology aggressively. On the other hand, to optimize the geometry and process parameters of sheet metal forming for economic batch production, sheet metal industries are using 3D printed tools for forming processes. In this study, the review of sheet metal forming processes is done based on the design of tooling development by Fusion Deposition Modelling 3d printing technology. Further process parameters like punch force, blank holding force, anisotropy, clearance, bend allowance are studied for deep drawing and V-bending process. In a later stage cost, comparisons of standard steel tools and polylactic acid (PLA) tools are carried out on basis of volume, density, and cost. The findings suggest that 3d printed tools can be used for small lot production due to easy availability and flexibility in the manufacturing system of the sheet metal forming process.

Tube and Sheet Metal Forming Processes and Applications

In the late 1960s, pioneer works by Keeler [...]

Design and implementation of magnetic field effect sensor for ISF process

In this paper, an efficient approach for sheet metal thickness measurement is proposed. It is based on the concept of magnetic field effect resonance commonly called as Hall effect. The combination of magnet and metal tools generates the DC voltage signal. The magnitude of the generated signal is inversely proportional to the distance between magnet and tool and hence the thickness of the sheet metal. The proposed idea is designed and implemented successfully using suitable hardware. Initially, the designed circuit is tested manually using the Hall-effect sensor and the sheet metal of different thicknesses. Further, the various experimentations are carried out on the complete CNC machine-based incremental sheet metal forming setup to examine the effectuality of the proposed design. Moreover, the evaluation of the manufactured ISF part has been carried out using the image processing technique. It is observed that the proposed approach can be used efficiently in the application such as the incremental sheet metal forming (ISF) process in real-time for thickness measurement.

Fuzzy logic model-based punch force prediction for deep drawing of high strength steel

The process of sheet metal forming is referred to as Deep Drawing. It is applied to make hollow–curved metal surfaces using a die and punch which creates the hollow burrow. This process is widely used in various industries to form sheet metals into automatic parts of certain requirements. The punch force applied in the die depends upon various parameters. The punch force is also responsible for the effective outcome of the deep drawing of the metal sheet. Thus, a set of process parameters that majorly affects the punch force is decided and those experiments were done to obtain the punch force at different values for different input parameters. Producing punch force requires huge energy expenditure. Hence, for the process to be both economical and efficient – lower punch forces are preferred. But when multiple parameters are considered, it becomes difficult to obtain the lowest punch force value. Hence, with the L27 orthogonal array, the number of combinations of the experiments that need to be done is reduced phenomenally. These experimental data were used to create a fuzzy logic model using MATLAB software. Therefore, a Fuzzy Logic Model was generated with the considered parameters being the input and the punch force being the output. This model will be used for punch force prediction as well as finding the optimized input parameters to achieve the lowest punch force.

A new void coalescence mechanism during incremental sheet forming: Ductile fracture modeling and experimental validation

• Investigated a new void coalescence mechanism and its effect on ductile fracture of ISF. • Improved formability of ISF is attributed to closely-packed void cluster. • Proposed extended GTN model for ISF by considering oriented void cluster. • Validated proposed model with various process conditions and deformation states. The forming limit of sheet metal can be significantly improved by incremental sheet metal forming(ISF) process, however lacks of relevant fundamental researches. Besides, accurate prediction of formability based on deeper understanding of deformation mechanism is beneficial for the evaluation of ductile failure behavior in ISF process. In the present work, a new void coalescence approach, that voids coalesce closely along meridianal direction rather than conventional thickness direction, is proposed and its influence on formability is investigated. The improved formability is attributed to the formation of closely-packed void clusters along meridianal direction, and these void clusters can stably exist inside the sheet metal even after void coalescence. By introducing two independent parameters into classic GTN model, an extended GTN damage model is developed to describe this new void coalescence mechanism in ISF process, and is validated through a series of experiments. Through investigations in this work, the fundamental understanding of improved formability in ISF is revealed, and the extended GTN model shows its comprehensive capability in predicting ductile fracture behavior with a satisfactory accuracy.

Efficient Computation of the Sharpest Bounds on the Probability of Failure of a Sheet Metal Forming Process

AbstractThe determination of the sharpest bounds on the probability of failure (PoF) based on the Optimal Uncertainty Quantification (OUQ) framework relies on the solution of non‐convex global optimization problems. These problems are subjected to non‐linear constraints to reflect moment constraints from available data, which impedes the numerical efficiency of the method. A different parameterization approach of the optimization problem utilizing canonical moments allows the transformation to only bound constraints and hence, an improved numerical efficiency can be reached. The performance of this new approach is contrasted with the performance of the original approach on the basis of a numerical simulation of a sheet metal forming process.

A COMPARATIVE STUDY ON DEEP DRAWING PROCESS AND AUTOFORM SIMULATIONS OF DX54D + Z and DX56D + Z STEELS

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.

Emerging Trends in Single Point Incremental Sheet Forming of Lightweight Metals

Lightweight materials, such as titanium alloys, magnesium alloys, and aluminium alloys, are characterised by unusual combinations of high strength, corrosion resistance, and low weight. However, some of the grades of these alloys exhibit poor formability at room temperature, which limits their application in sheet metal-forming processes. Lightweight materials are used extensively in the automobile and aerospace industries, leading to increasing demands for advanced forming technologies. This article presents a brief overview of state-of-the-art methods of incremental sheet forming (ISF) for lightweight materials with a special emphasis on the research published in 2015–2021. First, a review of the incremental forming method is provided. Next, the effect of the process conditions (i.e., forming tool, forming path, forming parameters) on the surface finish of drawpieces, geometric accuracy, and process formability of the sheet metals in conventional ISF and thermally-assisted ISF variants are considered. Special attention is given to a review of the effects of contact conditions between the tool and sheet metal on material deformation. The previous publications related to emerging incremental forming technologies, i.e., laser-assisted ISF, water jet ISF, electrically-assisted ISF and ultrasonic-assisted ISF, are also reviewed. The paper seeks to guide and inspire researchers by identifying the current development trends of the valuable contributions made in the field of SPIF of lightweight metallic materials.

Blank Shape Optimization Considering 3D Space Targets for External and Internal Boundaries in Sheet Metal Forming Processes

Optimum design of the shape of the initial blank is an important task before sheet metal forming processes. It reduces production costs, material waste and improves the quality of the product significantly. In the present work, the blank shape optimization problem is considered based on the 3D space target contours and moreover the sheet metal can have an internal boundary. In other words, the shape optimization process can be applied on the internal boundary, external boundary or both. To the best knowledge of the authors, there are no published works in this subject. Using the iterative simulation-based optimization process, a special shape error index and also updating algorithm were proposed to modify the blank geometry in each iteration until capturing the optimum shape. The sheet forming process is highly nonlinear in nature due to plastic behaviors, large deformations and frictional contact surfaces. Therefore, the updating formula should be robust enough to have less sensitivity with respect to the initial guess. To evaluate the proposed updating formula and its robustness, some numerical examples were considered and the effects of different tools geometries, 2D and 3D target contours, internal and external boundaries and different initial guesses were examined.

Application of Associated and Non-Associated Flow Metal Plasticity for F.S.S Sheet

In the last decade, several phenomenological yield criteria for anisotropic material has been proposed to improve the modeling predictions about sheet metal-forming processes. In regard to this engineering application, two proprieties of models have been used. If the yield function and the plastic potential are not same (not equal), the normality rule is non associative flow rule (NAFR), otherwise, when the stresses yield has been completely coupled to the anisotropic strain rate ratio (plastic potential), is called the associated flow rule (AFR). The non-associated flow rule is largely adopted to predict a plastic behavior for metal forming, accurately about à strong mechanical anisotropy presents in sheet metal forming processes. However, various studies described the limits of the AFR concept in dealing with highly anisotropic materials. In this study, the quadratic Hill1948 yield criteria is considered to predict mechanical behavior under AFR and NAFR approach. Experiment and modeling predictions behaviour of normalized anisotropic coefficient r (θ) and σ (θ) evolved with θ in sheet plane. and the equibiaxial yield stress σb was assumed σb=1 but the rb-values was computed from Yld96 [15].

Numerical Simulation as a Tool to Predict Sheet Metal Forming Process of TRIP Steel HCT690

Numerical Simulation as a Tool to Predict Sheet Metal Forming Process of TRIP Steel HCT690

Design and Analysis of Die for Brake Hose Bracket

One of the promising methods for the manufacture of complex shapes is the Sheet Metal Forming process. The Brake hose bracket is made using this process using several procedures for its manufacture. In this work, the processes carried out for the manufacturing of Brake hose bracket has been studied using Finite Element Analysis carried out using commercial analysis software, ANSYS. The making of the Die and Punch for the manufacture of the Sheet metal forming process of brake hose bracket. The bracket is made of mild steel material and the results were obtained and were in good agreement with that of the experimental values. The Stress distribution, Strain distribution and deformation experienced by the component and the die cavity during manufacturing process has been investigated and the conclusion were made. The FEM method proves to be efficient in understanding the stress and strain distribution in the component.

Investigation on the Crack and Thinning Behavior of Aluminum Alloy 5052 Sheet in Stretch Flanging Process

Stretch flanging is the important sheet metal-forming process which is widely used in automobile and aerospace sectors. The formability of sheet metal depends on various parameters such as material properties, geometry of the tool setup and process parameters. In the present work, effects of different die radius and sheet width on deformation behavior of sheet are studied by FEM simulation and experiments. The predicted FEM results are presented in the form of edge crack location and its propagation, crack length, forming load and strain distribution in sheet along the die profile radius. This study indicates that crack length increases with increase in the sheet width, while the crack length decreases with increase in the die radius. It is found that the crack propagation in stretch flanging process is affected by the strain distribution in sheet and this distribution of strain depends on many parameters. The crack initiates during deformation of the sheet at the die corner edge and propagates toward the center of the sheet along the die profile radius. Simulation results are compared with the experimental one in terms of crack length and variation in sheet thickness. FE simulation results are found in very good agreement with experimental results. Fractography study is also presented in terms of size, shape of the dimples along with their distribution on the fractured surface.

SIMULATION AND EXPERIMENTAL INVESTIGATION OF WRINKLE DEFECT IN DEEP DRAWING PROCESS OF CARBON STEEL SPCC SHAPED CYLINDER FLANGE CUP

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. One of the problems in the SMF process is the wrinkling phenomenon, which can cause the size and appearance defects of sheet products. The wrinkle occurs because of the mechanical properties of the material, product geometry, and blank holder force (BHF). Several variations of BHF were applied in these simulations and experiments to eliminate the wrinkle defects of cylinder flange cup test products. The characteristic of the cylinder flange cup is from the cold-rolled coiled steel plate (SPCC) type of material with a thickness of 0.8 and 1.0 mm, the height of 10 mm, the inner diameter of 58 mm, and flange diameter of 76 mm. Simple simulations of the SMF process were carried out by using Solidworks with version 2017, and the experiment was carried out at a 600 kN press with a punch velocity of 40 strokes per minute and blank holder force variations from 0 to 21 kN. The experimental data performed with a single die on a flanged cup cylindrical test material shows that the higher the blank holder force (BHF) number, the smaller the wrinkle defect, and it can be eliminated starting from the BHF number of 15 kN.