Experimental stress analysis for process of nonsteady inelastic deformation by photoviscoplasticity

The proposed photoviscoplasticity is a method for determining the stress distribution in nonsteady inelastic deformation during creep. The governing fundamental relations are derived by considering the effect of time as involved in the viscoplastic strain rate and the stress rate, and by considering the distinctive deformation properties of celluloid as model material. The validity of the fundamental relations are evaluated according to calibration test by using celluloid. The proposed method is applied for two practical applications of the compression of blocks by elastic punches and the compression of strip having a circular hole or semicircular notches. The time-dependent variation of stress states can be analyzed with the same accuracy as in the photoelasticity.