Mechanics of Sheet Metal Forming

2005

Sheet metal forming technologies are challenged especially by the improvements in the automotive industry in the last decades. To fulfill the customer expectations, safety requirements and market competitions, new production technologies have been implemented. This study focuses on the assessment of conventional and new sheet metal forming technologies by performing a systematic analysis. A geometry spectrum consisting of six different circular, elliptic, quad cross-sections are selected for the assessment of conventional deep drawing, hydro-mechanical deep drawing and high-pressure sheet metal forming. Within each cross-section, three different equivalent drawing ratios are used as a variant. More than 200 numerical experiments are performed to predict the forming limits of three competing processes. St14 stainless steel is used as the material throughout the assessment study. The deformation behavior is described by an elasto-plastic material model and all numerical simulations are carried out by using dynamic-explicit commercial finite element code. The process validation is done by interpreting the strain results of numerical experiment. Therefore, the reliability of predictions in the assessment study highly v depends on the quality of simulations. The precision of numerical experiments are verified by comparing to NUMISHEET benchmarks, analytical formulation, and experiments to increase the assets of the assessment study. The analyses revealed that depending on the workpiece geometry and dimensional properties certain processes are more preferable for obtaining satisfactory products. The process limits for each process are established based on the analyzed crosssections of the spectrum. This data is expected to be useful for predicting the formability limits and for selecting the appropriate production process according to a given workpiece geometry.

In this paper the possibilities of the viscous voided shell approach for deriving bendinglmembrane finite elements for sheet metal forming problems are presented. These elements can be selectively used for membrane or full bending analysis of some parts of the sheet according to the nature of the deformation. Numerical aspects of this approach are discussed and some examples of application are also given.

IJRAME PUBLICATIONS, 2025

The sheet metal forming operations process involves the Male (Punch) and the female (Die). The procedure is of sheet metal deformation due to the relative movement between the punch tool and the sheet, an interaction that generates friction forces between the elements. The formability of AISI 304 stainless steel sheets is examined in this study using the Nakajima test specimen. The Nakajima test is a widely used method for evaluating the formability of sheet metals. The forming limit diagram (FLD) of AISI 304 steel sheets is experimentally determined in this work using the Nakajima test. Additionally, the FEA HyperForm Radioss software is used to simulate the forming process and validate the experimental results. The effects of various process parameters, such as punch speed and lubrication, on the formability of AISI 304 steel sheets are also investigated. The results of this study offer valuable insights into the formability of AISI 304 steel sheets, which can be utilized to optimize the sheet metal forming process.

Sheet Metal Forming Processes, 2010

The deep drawing process is a forming process which occurs under a comb ination of tensile and compressive conditions. Formability is the ability of a given metal work piece to undergo plastic deformation without being damaged. The p lastic deformation capacity of metallic materials, however, is limited to a certain extent, at which point, the material could experience tearing or fracture. Formability of sheet metal can be evaluated by various tests like swift cup drawing test, fukui's conical cup drawing test , erichsan cupping test, osu Formability Test, Hydraulic Bulge Test, Duncan Friction Test. These tests are widely used to evaluate of formability for different sheet metals. In this paper, swift cup a nd erichsen cupping tests presented.

2017

Sheet metal forming processes like bending, deep drawing process, and hydro forming involves forming of sheet metal in required shape from blank. Simulation of these processes is highly essential for many reasons like high cost involved in experimentation, elements of uncertainty involved trial and error manufacturing forming dies due to elastic recovery. This research paper aims to review attempts made by several researchers in simulation of these processes using various ways,.

CIRP Annals

The Journal of Engineering and Fundamentals, 2015

A sheet metal assembly must meet functional, manufacturing, and sometimes also esthetical requirements. The properties of the assembly are to a large extent affected by the manufacturing process, i.e. the forming processes of the sheet metal components and the subsequent assembling sub-processes. It is of a great industrial interest to be able to predict the properties of the assembly at an early design stage. This paper presents a methodology, based on Finite Element simulations, which makes it possible to accurately predict the properties of a sheet metal assembly. Each forming process of the individual components is simulated, and all properties affected by the forming process are included in the subsequent simulations of the assembling process. Thus, this methodology makes it possible to optimize both the functional properties of the assembly and also its manufacturing process considering all mechanical effects introduced by the individual manufacturing processes. A case study o...

International Journal of Microstructure and Materials Properties, 2013

Sheet metal forming is one of the most important key technologies in manufacturing industry. It may be reasoned by several facts, among them the economy of the sheet-forming processes concerning the material and energy consumption, as well as the overall cost efficiency. To keep this key role of sheet metal forming in manufacturing industry, a continuous development is necessary concerning the materials, the development of new innovative forming processes, the tooling and manufacturing equipment. The ever-increasing requirements stated by the automotive industry may be regarded as one of the main driving forces behind sheet-metal-forming innovations. In this paper, some recent developments in sheet metal forming will be overviewed concerning the materials and process developments, as well as the application of various methods of Computer Aided Engineering (CAE).

A new approach to solving the problem of the sheet-flange corrugation in the process of forming cylindrical sheet-metal elements is presented. A brief characteristic of the dynamic central-difference method is given. Technological parameters of a forming disk, a die block and a plunger die have been selected from references. Sample results of computer simulations with stress distributions in a disk are presented and serve as the basis for discussing the process of sheet metal forming.