Prediction of Tool Force in Two Point Incremental Forming by Slab Analysis

Two-Point Incremental Forming (TPIF) method is a novel technique for producing free form shell parts. The main purpose of this study is to analyze the TPIF process, and, by approximate calculation, to find the force applied to the tool. One of the limitations of an incremental forming process is that during this process force applied to the tool is born by the machine. In this research, an equation for approximate prediction of the force applied to the tool is presented using the values of the yield stress of the sheet, friction coefficient, tool radius and thickness of the sheet; hence, the applied force can be calculated. By increasing the forming angle, the amount of the created local strain increases and the change in thickness and the force applied to the tool is enhanced. However, by increasing the angle of punch wall, less compressive stress is applied to the metal sheet due to the reduction in contact between the surface of the tool and punch wall. Analytical equations presented are validated by the results from experimental tests.