Dynamic analysis of shafts of composite materials

Abstract

The objective of this study is to analyze the dynamic behavior of composite shafts with particular interest on estimation of damping. The composite shafts have been chosen as potential candidates for the replacement of conventional metallic shafts in many applications. This study analyzed the dynamic behavior of different materials such as glass/epoxy, carbon/epoxy, and boron/epoxy at different speeds. Detailed dynamic studies on the effect of different materials, stacking sequences on the unbalance responses, and eigenfrequencies are required, particularly with respect to the damping present in the composite material. Different methodologies such as logarithmic decay curve, half-power method, and hysteresis loop method using force sensors have been used for determining the damping of the composite shafts. Composite tube-shafts and solid shafts have been modeled and analyzed using ANSYS. A parametric study has been carried out to analyze the effect of stacking sequence on eigenfrequencies of composite tube-shafts. This study aims to have a comprehensive view of numerical and experimental analyses of composite shafts for eigenvalues, damping estimation, and unbalance response. Eigenfrequencies of composite tube-shafts and solid shafts were estimated through modal testing and are compared with analytical and FEM results. In this study, torsional vibration analysis for composite solid shafts has also been carried out using the rotational laser vibrometer.