A BIAXIAL THERMOMECHANICAL DISK TEST FOR GLASSY-POLYMERS

Failure criteria for polymers need to include effects from the stress state, For this reason, biaxial test results are of interest, However, biaxial test methods usually require expensive equipment. In the test method presented here, a disk of epoxy is bonded between a steel ring and a steel disk, The temperature is then lowered until fracture is o bserved, Experiments were performed on th ree different glassy epoxy p olymers, The biaxial stress state was analyzed by finite element analy sis and by an approximate analytical model, Experimental observations support the ability of the method to provide material property data, A n approximate analytical model was found sufficiently accurate for str ess analysis and determination of the stress state at failure.