Computer aided simulation of three-dimensional deformation behavior of sheet metal during COLD ROLL FORMING process is described In this simulation, the shape of deformed sheet metal is expressed by an approximated mathematical equation called "Shape Function". By means of this shape function, stress and strain distribution and dissipated energy in the deformed sheet metal can be calculated by a computerized incremental procedure using Hooks law in the elastic range and Levy - Mises equations in the plastic range. The optimum shape of deformed sheet can then be predicted by minimization of the calculated energy.By the simulation, it was possible to explain various characteristics of the COLD ROLL FORMING process. The authors believe that using Levy - Mises equations simplifies the previously proposed methods and at the same time the results seem to be quite encouraging.

COLD ROLL FORMING is a sheet metal FORMING process in whichthe bending occurs gradually in several FORMING steps from an undeformed strip to a finishedprofile. Althoughsimple appearance, the process is influenced by several parametersthat complicate the process design and control such as springback.The main purpose in this article is to determine a simple criterion for the springback and to introduce a fast solution to obtain it and therefore artificial neural network was proposed for achiving this goal. COLD ROLL FORMING of a channel section in the first station was simulated by a commercial package named “Msc Marc Mentat”. The data obtained from the finite element simulations were used as training and testingsetsfor neural networks. Perfect performance of neural network was proved when the neural network outputs were compared with the testing set that did not exist in the training set.

COLD ROLL FORMING is the most popular process that is widely for manufacturing pipe by FORMING strips into a cylindrical shape which are then welded by electric resistance welding. In this study, an elastic-plastic deformation behavior of the strip was investigated by using the FEM method. Therefore a 2D modeling has been done by means of FEM software, Ansys, to examine effective parameters on the final shape of the strip edge. Also the effects of the parameters such as fin angle at fin ROLLs and the proportion of the strip thickness per final pipe diameter (t/D) were considered on the final shape of product. Some experimental works have been done in Ahvaz Pipe Company that successfully there were an acceptable consistency among experimental results and obtained outcomes from 2D simulations and also results from other researchers.

In this study, “Buckling Limit of Strain” (B.L.S.) is introduced as one of the most important limiting factors in COLD ROLL FORMING process. B.L.S. is calculated by the finite element procedure. Then for two particular processes with existing analytic and experimental results, B.L.S. has been determined and evaluated. LUSAS 12.3 is used for finite element analysis. The results show that when buckling of the sheet metal is the limiting factor, B.L.S. is in good agreement with practical limits. It has also been shown that flower pattern can be well predicted when B.L.S. is obtained and this idea is another new outcome from this study. Using this criterion to define and determine B.L.S. and to design the flower pattern is a new concept accomplished for the first time.

The COLD ROLL FORMING is one of the common processes to form metal profiles in the industry. Due to the nature of the bending deformation in COLD ROLL FORMING process, spring-back is one of the most important defects. In order to compensate the spring-back, the amount of spring-back must be correctly predicted. In this article, the effect of the hole and its position on the spring-back has been investigated by experimental and numerical methods. three channel section profiles made of St12 and thickness of 1 mm, without hole, with circular holes on the bend area and with holes on the flange were used. COLD ROLL FORMING was done in three stations with a fixed bending radius pattern with 15 degree bending in each FORMING station and numerical solution using Abaqus finite element software. The results indicate that there is a relationship between the amount of spring-back and the position of the hole in such a way that the amount of spring-back in hole on the bend area profile is 9% more than the hole-less profile and in hole on the flange profile is 16% less than hole-less profile. Also, according to finite elements results, it was observed that the amount of equivalent strain in the bend area of the profile with holes on the bend area is 20% less and in the profile with holes near the bend area is 16% more than the profile without holes, which can justify the difference observed in the amount of spring-back.

COLD ROLL FORMING is a process in which a metal sheet gets a desired section form by passing through a series of rotating ROLLers. Predicting the amount of the distortion in pre-notched COLD formed sections still remains challenging in COLD ROLL FORMING industry, depending on the shape and position of the holes. This study investigates the influence of variation of the design parameters on the defects of the U-channel sections produced by COLD ROLL FORMING process with circular pre-notches. To analyze the important parameters in deFORMING the circular holes during the COLD ROLL FORMING of U-channel sections, a three-dimensional finite element model has been taken into account. A range of variation for design factors in FORMING the U-channel sections with pre-notches is set, including radius of circular holes, distance between the holes and the flange edge, hole spacing, sheet thickness, and type of material. Furthermore, using the response surface methodology, a set of tests are designed and modeled employing Finite Element analysis. Afterward, a set of output parameters such as edge buckling, the wave of the holes, the change in hole size, hole spacing, and the distance between the holes and the edge of the flange, are considered. Utilizing Analyses Of Variance (ANOVA), the accuracy of the linear regression models was conducted in this study. The accuracy of the simulated models is examined by comparing the analysis results with the experimental results. Finally, the effect of the important parameters on the defects of the product has been extracted in both the statistical form as well as mathematical functions applying response surface methodology. The results show that as the radius of the hole increases, edge buckling increases. The increase of the hole radius increases the edge wave on the holes. The hole width of the product is bigger and the hole length is smaller than the nominal measuring.