抄録
The fringe order obtained by the photoplastic test gives important information on the mechanical properties of transparent polymers. However, the effect of viscosity on the fringe order has not been investigated sufficiently. In this paper, the time-dependent photoplastic properties of Cellulose Acetate was examined by means of the recovery test under uniaxial tension. The optical and the mechanical characteristics after unloading were measured as a function of elapsed time. As a result, it was observed that the recovery of both strain and fringe order increase rapidly at first, and then gradually approach constant values. Moreover, the relation between the residual strain and fringe order during recovery is represented in a linear relation independent not only of room temperature but of recovery time. In addition, strain and fringe order obtained by loading below the yield stress vanish completely by unloading and recovering.