Viscoelastic Characterization and Self-Heating Behavior of a Flexible Matrix Composite Driveshaft

Flexible matrix composites (FMCs), consisting of high-elongation, low modulus elastomers reinforced with high-stiffness continuous fibers, offer a high degree of elastic tailorability not found in typical structural polymer matrix composites. In the current investigation, the frequency- and time-dependent anisotropic viscoelastic behavior of an FMC material is characterized at the lamina level using a fractional derivative approach. The viscoelastic lamina properties are input to an elasticity model to predict the viscoelastic properties of filament-wound, angle-ply FMC driveshafts. The model is validated with experiments carried out using shafts of various fiber angles under tensile and torsional loadings. A thermal and mechanical analysis of a spinning, misaligned shaft is then carried out to predict self-heating in the shaft. Comparisons of the self-heating behavior with experiments indicate good agreement for several different shaft fiber angles. The models proposed in this investigation can be used to minimize the number of experiments that need to be done to predict the viscoelastic self-heating of FMC shafts as well as other types of composite shafts.