Dynamic Viscoelasticity of Carbon Fibre Reinforced Polymers under High Load: Effects of Static and Dynamic Loads

Abstract

The load applied on the specimen in common dynamic mechanical thermal analysis (DMTA) is of the order of several Newtons to several tens of Newtons, far lower than that in service life. In this study a dynamic mechanical thermal analyser (EPLEXOR 500, with a total load up to 500 N) was applied to investigate the effects of static load and dynamic load (sine-wave load) on the dynamic viscoelasticity of unidirectional carbon fibre reinforced epoxy resin composites. The effects of the load on the dynamic viscoelasticity of polymer matrix composites (PMCs) are expressed mainly in two ways. On the one hand, the load affects the magnitude of the dynamic viscoelastic parameters. The storage modulus increases with increasing static load and decreases with increasing dynamic load. Such variations are obviously related to the interaction between the two kinds of load. The increase in load, whether static or dynamic, can result in a decline in the loss tangent. On the other hand, there exists a frequency-temperature-load equivalence for a carbon fibre-reinforced polymer's dynamic viscoelasticity. An increase in static load raises the glass-transition temperature and pushes the frequency spectrum curve towards a low frequency, while the effects of dynamic load are the reverse.

A Multifaceted Approach for Cryogenic Waste Tire Recycling

“…Glass transition depends not only on the temperature, but also on the nature of the mechanical load. Thus, under static loads or dynamic loads of low frequency, the glass transition temperature is lower than under dynamic loads of high frequency [ 54 ]. From this perspective, it is clear that the most accurate measurement of the cooling depth of samples and mechanical effect after freezing are necessary to optimize the low-temperature method for rubber waste recycling.…”