A CONSTITUTIVE MODEL OF POLYMER MATERIALS INCLUDING CHEMICAL AGING AND MECHANICAL DAMAGE AND ITS EXPERIMENTAL-VERIFICATION

The influence of chemical ageing and microcrack damage on the mechanic al behaviour of polymer materials is studied. The theoretical model is derived from irreversible thermodynamics, chemical reaction kinetics and a crack extending model. Ageing tests, swelling tests, acoustic em ission tests and relaxation tests have been done to determine the mate rial constants of the constitutive equations. The consistency between the theory and the experiments is quite good when the model is applied to HTPB composite solid propellant materials.