Viscoelastic Wave Interaction with Cylindrical Cavity

Stresses at a free-field point and on the boundary of a circular hole in a viscoelastic plate subjected to air shock loading were determined by photoviscoelastic and moiré methods. The model material used was plasticized polyvinyl chloride, which is soft, transparent, and photoviscoelastic. Its relevant mechanical and optical properties were determined by creep tests at different temperatures using the temperature-time equivalence principle and by sinusoidal oscillation tests. A dynamic viscoelastic stress distribution around the hole was determined and compared with that obtained from the free-field stresses and classical elasticity. Results indicate that the dynamic viscoelastic stress concentration factor exceeds the static one appreciably in the beginning, but approaches the latter with time.