Experimental investigation on effect of tangential viscous adhesive stress on strain distribution of polycarbonate sheet

摘要

The tangential viscous adhesive stress on the interface of sheets and viscous medium is one ofnthe most crucial factors affecting the formability of the sheets in viscous pressure forming. A novelnexperimental method, referred to as the viscous adhesive tensile test, is proposed to investigatenthe deformation behaviour of sheets subjected to the tangential viscous adhesive stress. Thenphotoplastic method, a type of non-contact measuring method, is applied to analyse the in-planenstrain distributions. The thickness strains are calculated based on the thickness changes of thenspecimens. Uniaxial tensile tests are also conducted for comparison. Experimental resultsnindicate that the tangential viscous adhesive stress can promote the material flow of the specimennand improve thickness uniformity. Thus, the effect of tangential viscous adhesive stress on thenformability improvement of sheet in VPF is experimentally verified.