Mechanical Characterization Technology On Aging Properties Of Rubber Composites

In the storage process,, the mechanical property of rubber composites andtheir adhesive structure will decline and even fail eventually due to temperature,humidity, stress and other environmental factors, and this will have a seriousimpact on system stability and security. From this point of view, it becomes moreand more significant to study the aging mechanical properties of rubbercomposites and their adhesive structure.This paper study the aging of solid propellant which uses rubber as matrixand the propellant-lining adhesive structure，mainly includes the research of themethods for characterizing the relaxation time, the research of the adhesivestructure aging mechanism, the research of the adhesive structure agingcharacterization technology.Propellant is a typical viscoelasticity material. relaxation time as an importantmaterial parameter can be used to characterize the aging of propellant material. Inthe test method of relaxation properties, dynamic mechanical analysis is fast and ituse less test specimen. But it will have a larger deviation when calculatingrelaxation modulus by the existing formula between static and dynamic properties.This paper gives a empirical formula between static and dynamic properties basedon experimental data and viscous elasticity theory.In addition, it provides anapproach to characterize the aging of rubber composites by using relaxation ti meas characteristic parameters.In order to find a way to research the failure mechanism of the adhesivestructure, we design an experiment to study the effect of the two failuremechanism (Component migration and thermo-oxidation aging) on the aging ofadhesive structure. The result of the experiment shows that the effects of the twofailure mechanisms will change in different periods. At the early stage, the agingComponent migration has a more significant influence on the adhesive structureaging, while at the later period the thermo-oxidation aging occupied the leadingrole.This paper considers uniform aging and non-uniform aging caused byComponent migration and thermo-oxidative aging. The aging mechanical model ofthe adhesive structure which contains reserve crack is established. Then wecalculate the J-integral of crack tip in different aging conditions.The analysis ofexperiments data shows that the non-uniform aging model of coupling multipleaging mechanisms is more rational and safety. On this basis, a method ofcharacterizing the adhesive structure aging which uses J-integral as characteristic parameter is put forward.Conclusions from this study provide reference for the aging research andpractical applications of the rubber material and its adhesive structure.