On the testing equipment and experimental techniques for the investigation of the photoviscoelastic behaviour of soft polymers

Creep tests with uniaxial stress and pure shear have been carried out in order to determine the behaviour of soft plastics, which is governed by a non-linear material law, and to apply it to the photoelastic analysis of biaxial stress in plastic components under quasistatic and isothermal loads. The test facility is described as well as the technique applied to correct stress/creep curves for sigma=const. Results are presented for plane and tubular samples of soft PVC and an unsaturated polyester. (orig.)