In this paper instability of planar anisotropic sheet metal during a few forming processes is investigated for the first time. For this reason components of the constitutive tangent tensor for planar anisotropic sheets are developed. By using the above tensor location of necking is predicted. Direction of the shear band is also predicted using the acoustic tensor. A finite element program is pr...

For ̄ exible manufacture of a doubly curved sheet metal, a new sheet metal forming process is proposed that uses a movable punch set composed of two pairs of lower support punches and one upper centre punch. The process is characterized by ̄ exibility compared with the existing conventional processes because it does not require any complex-shaped die and the loss of material is minimized by unc...

Deep drawing of two-layer sheet is a suitable way to achieve product with a desired shape and desired properties in sheet metal forming technology. Control of deep drawing parameter such as thinning is the most important challenge in this process. The most difficult part of this challenge is differences in material properties and geometry of each layer. In this paper, numerical approach has bee...

The cup drawing is a basic deep drawing process. Thus, understanding the mechanics ofthe cup drawing process helps in determining the general parameters that affect the deep drawingprocess. There are mainly two methods of analysis; experimental and analytical/numerical.Experimental analysis can be useful in analyzing the process to determine the process parameters thatproduce a defect free prod...

Within the Brite/EuRam project “DIGIMAN” a new optical measuring system for the assessment of sheet metal components in terms of shape accuracy and strain distribution has been developed. Based on the photogrammetrically measured geometric parameters of the object the system detects deviations from the desired geometry caused by springback and allows the strain analysis within critical stamping...

Roll forming process is used for manufacturing sheet metal parts by successive bending and creating the final shape with gradual deformation. In this article, deformation of a pre-punched sheet due to the roll forming process was studied. Two main defects in the roll forming process are ovality of holes and bow defect. The ovality of the hole is influenced by the process parameters including sh...

In this paper, Computer Aided Designing (CAD) in conjunction with Rapid Tooling is applied to design and produce forming tools (punch and die) for stretch-formed jewelry (generated on thin sheet metal on top of which jewelry patterns are raised with forming tools by stretching the sheet metal beyond its elastic limit. The work presents a parametric voxel based CAD paradigm for modeling of such ...

Sheet metal forming is one of the major processes in manufacturing and is broadly used due to its high degree of design flexibility and low cost. In the sheet metal forming process, draw-in (planar movement of a sheet periphery) frequently occurs and is one of the most dominated indicators on the success of a forming process. Currently, monitoring and controlling draw-in during each stamping op...

shape error due to elastic recovery of formed part in unloading known as springback, is one of the most important problems of tool design in sheet metal forming processes. many researches have been performed for proposing an efficient method to decrease or compensate springback error in sheet forming processes. these methods are usually based on iterative finite element algorithms. in this pape...