Optimization of the roll forming process of U channels using a hybrid response surface and desirability function approach

Abstract

In the roll forming process, control of input parameters is essential in order to maintain the quality of the final profile. In this investigation, a new hybrid approach is used for optimization of the roll forming process. That is based on the finite element simulation. Firstly, the process was modeled using the finite element method and then verified with the experimental results. Then necessary experiments have been designed using the central composite design method. In this design roll diameter, distance and number of stands and linear velocity of the sheet are considered as input variables and maximum plastic longitudinal strain and angle precession (reverse of spring back) are considered as response functions. Then the response surface model of the objective functions was obtained using the response surface method based on the finite element outputs of the runs. Finally, optimum point of the input parameters has been obtained using the desirability function approach. Results show that the response surface method can model the effect of the input parameters on the objective functions precisely. According to this model, increasing of distance of the stands and roll diameter, lead to decreasing of maximum plastic longitudinal strain. Increasing the linear velocity of the sheet leads to decreasing the maximum plastic longitudinal strain. Decreasing distance and increasing number of stands cause to increase the angle precession and increasing the linear velocity of the blank leads to decreasing of the angle precession. Also optimization results represent increasing of the angle precession and decreasing of the maximum plastic longitudinal strain in comparison to conventional results.

Keywords

• roll forming
• optimization
• response surface method
• finite element
• desirability function