Abstract
A simplified optical method based on photoviscoelasticity is proposed for measuring the transient stress and strain generated in a two-dimensional photoviscoelastic body. First, the fundamental equation for the simplified optical method is derived from the relationships between the stress, strain and birefringence in the two-dimensional photoviscoelastic body based on the linear photoviscoelastic theory. As examples of the application, transient principal strain and its direction in a square plate with a circular hole of polyurethane resin produced by non-proportional loading under a constant temperature are measured by using the simplified optical method. Next, residual stress in a beam of epoxy resin by rapid cooling is also measured by this method.
