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...

The most often used friction model for sheet metal forming simulations is the relative simple Coulomb friction model. This paper presents a more advanced friction model for large scale forming simulations based on the surface change on the micro-scale. The surface texture of a material changes when two surfaces are in contact under a normal load. This is caused by flattening due to combined nor...

Expert system can be defined as an intelligent computer program, a repository of knowledge, a set of rules, like a human consultant, all aiming at delivering accurate solutions/suggestions to a problem at any level, say during plan, design, manufacture, and quality control. Some of the important definitions are quoted here. “An expert system is a computer system used to distribute the expertise...

Point vortex and vortex blob computations are used to investigate the evolution of the planar and the axisymmetric vortex sheet which initially induce ow past a cylinder and past a sphere respectively. In both cases the sheet develops a singularity at two points in the symmetry plane at a nite time. It rolls up at these points forming a vortex pair in the planar case and a vortex ring in the ax...

A literature review of sheet metal forming errors as well as geometrical dimensions and tolerances (GD&T) shows that the theoretical means for the allocation of process tolerances with respect to GD&T are insufficient. In order to judge the influence of geometrical process errors (e.g., angular errors of bends), two typical sheet metal designs with parallelism and a position tolerance are studi...

In the article the changes associated with construction of machines used in die and die-less sheet metal forming have been presented. The selected future directions of development in new technologies and machines for sheet metal forming taking into account modern blank holding systems in the process of deep drawing have been indicated. Also the tendencies in introduction of new technologies and...