A Study on the Influence of the Forming Strategy on the Main Strains, Thickness Reduction, and Forces in a Single Point Incremental Forming Process

Adrian Blaga,Valentin Oleksik

doi:10.1155/2013/382635

Abstract

This paper comprises an experimental study for a complex geometry part obtained by incremental forming. Due to the process complexity (the presence of forces on three directions—a vertical one and two in the blank's plane), a three axes CNC milling machine, capable of describing the complex paths covered by the punch for obtaining the truncated cone-shaped parts, has been chosen. To obtain a truncated cone, three different trajectories were selected: in first and second variants after each vertical press having a constant step, the punch covers a circular path. The differences show that the following circular trajectory can start at the same point or can be shifted at an angle of 90° from the previous press point. In the last variant, the punch performs a spatial spiral trajectory. The main objective of our study was to determine the optimal forming strategy, by shifting the press position of the punch and the path it follows to obtain a truncated cone through single point incremental forming. Thus, the strain distribution can be homogeneous, and the thickness reduction and the process forces are minimal.

Highlights

The incremental sheet metal forming process is a modern method of material forming processes, with huge potential regarding the degree of flexibility and customization of the parts made through this process
The main objective of our study was to determine the optimal forming strategy, by shifting the press position of the punch and the path it follows to obtain a truncated cone through single point incremental forming
The main objective of the present study was to determine the optimal forming strategy by shifting the penetrating position of the punch and the path it follows to obtain a truncated cone through single point incremental forming, so that the strain distribution can be homogeneous and thickness reduction minimal

Summary

Introduction

The incremental sheet metal forming process is a modern method of material forming processes, with huge potential regarding the degree of flexibility and customization of the parts made through this process. With regard to single point incremental forming, Pohlak et al [1] developed a formula to calculate forces by taking into account the anisotropy of the material as well (which was described using Hill’s higher order mathematical model). Another approach to the single point incremental forming process has been identified in Silva’s analytical studies [2], which, in order to explain the phenomenon of crack occurring in a component part, consider the behaviour of the material in incremental forming to be similar to that of a membrane

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Conclusion