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Spring-Back in Multi-Point Discrete Die V-Bending

M R Abusrea1 , M Shazly2, A Elmokadem1, and A S Wifi1
1.Mechanical Design and Production Dept., Faculty of Engineering, Cairo University, Egypt.
2.Faculty of Engineering, The British University in Egypt, Egypt

Abstract—Sheet metal forming using Multi-Point Discrete Dies (MPDD) is a forming technique in which the punch and die surfaces are discretized using arrays of pins leading to manufacturing flexibility and the ability to produce more than one product with the same die. The present paper considers the spring-back problem of the V-bending process using a Multi-Point Discrete Die. An experimentally validated ABAQUS finite element simulation model is developed in the present study to predict the punch load-displacement, bending angle, and the springback factor. For the same material and thickness, larger pin size is found to reduce springback factor but with a tendency for dimples occurrence. For the same thickness and pin side length, the use of polyurethane elastic cushion (interpolator) is found to eliminate the dimples occurrence, but causes a deviation in the bending angle. Generally, the study suggests that using the elastic cushion, decreasing the pin size, and adding controlled over stroke coining enhance the conditions for obtaining accurate final V-bend angle.

Index Terms—Multi-point discrete dies, V-bending process, Sheet metal forming, Finite element method

Cite: M R Abusrea, M Shazly, A Elmokadem, and A S Wifi, "Spring-Back in Multi-Point Discrete Die V-Bending," International Journal of Mechanical Engineering and Robotics Research, Vol.4, No. 2, pp. 1-13, April 2015.