Influence of rheological behavior of low-melting alloy on instability and control method for sheet metal

Abstract

The wrinkling-free forming method for sheet metal forming based on the low-melting alloy (LMA) is a novel sheet forming method. However, the wrinkling phenomenon is affected by the transmission of loading force depending on the rheological behavior of material LMA. The effect of the rheological behavior of LMA medium on the wrinkling mechanism needs to be deeply studied. The blank holder force exerted by the LMA medium on the edge of the sheet is analyzed using the plane strain method. The critical stress of sheet deformation and wrinkling is studied by combining the classical energy method. The range of blank holder force was computed at the critical wrinkling stage. The flow resistance of the sheet material flowing into the plastic region is affected by the stress angle in the transition zone through numerical simulation and experimental methods. The influence of different forming process conditions on stress angle on the transition area is studied, and the evolution law of the stress angle and the material flowing status are revealed. The effect of the upper layer thickness of LMA, the temperature of LMA, and the dimension of LMA in the flange region on wrinkling occurrence are performed. Experiments are carried out to verify the results for analytical and FE simulation. The experimental results indicated that research results show that a decrease in the stress angle will increase the resistance of the sheet flowing to the plastic deformation region.