Mechanical properties of nonlinear viscoelastic materials
This thesis deals with the stress-strain behaviour of nonlinear viscoelastic polymers. A methodology is presented, which allows measuring comprehensively the material behaviour in dependence of time, temperature and loading level using strain rate controlled short term tensile tests. Model based calculation rules are developed, to simulate the stress-strain behaviour of nonlinear viscoelastic materials for any loading situation, for instance creeping, relaxation, alternating and dynamic loading states. Applying the time-temperature shifting principle, it becomes possible to simulate long term behaviour, bases on material data, measures in short term tests. Finally, it will be shown, that the here shown modelling approach – the so called deformation model – can be used to simulate non isothermal loading states. The performance of the simulation is shown by comparison with experimental data.
Another part of the thesis deals with the behaviour of nonlinear viscoelastic materials under multiaxial loading states. Therefore an adaption of the deformation model, which originally was developed for the description of uniaxial stress states, is done for biaxial stress states. Simulation results calculates with this enhanced deformation model are compared again with experimental results.Lesen Sie die deutsche Zusammenfassung auf Kunststoffe.de
Material testing, polymers, nonlinear viscoelasticity, modelling and simulation of material behaviour, strain rate controlled tensile test, time-temperature shifting principle, creeping, relaxation, nonisothermal loading states
Institute / chair: Fakultät für Maschinenwesen der Rheinisch-Westfälischen Technischen Hochschule
Technical consultant for expert services: Prof. Dr.-Ing. G. Menges (Betreuer), Prof. Dr.-Ing. G. W. Ehrenstein
Publication year: 1985
Provider: Wissenschaftlicher Arbeitskreis Kunststofftechnik (WAK) / Kunststoffe.de
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