Modelling and vibration of composite thin-walled rotating blades featuring extension-twist elastic coupling

Abstract

The modelling and vibration of composite thin-walled pre-twisted rotating blades of non-uniform cross-sections along their span, and featuring the extension-twist elastic coupling are addressed. To this end, Hamilton's principle is used to derive the equations of motion and the associated boundary conditions. In addition to the pretwist and warping restraint, the exotic properties of advanced composite material are used, and the efficiency of implementing the tailoring technique toward the enhancement, without weight penalties, of the vibratory behaviour of rotating blades is illustrated. Comparisons between the predictions by both Wagner's and Washizu's approaches are presented, and pertinent conclusions regarding the implications of the various geometrical and physical characteristics of the blade are outlined.

The Effect of Non-Conservative Compressive Force on the Vibration of Rotating Composite Blades

“…It was shown that the ply orientation and rotating speed affect both flap-lag and twist-extension coupled free vibrations. Oh et al [14] addressed the vibration analysis of thin-walled pre-twisted composite blades. It was shown that the extension-twist elastic coupling and the blade pre-twist affect the dynamics of the composite blade.…”

Modeling and control for rotating pretwisted thin-walled beams with piezo-composite

“…Oh et al discussed effects of pretwist and presetting on coupled bending vibrations [10]. He also investigated the twist-extension elastic coupling effect on rotary composite structure [11].…”

“…In addition, transverse shear strain, primary and secondary warping inhibitions, three-dimensional strain, centrifugal stiffening and tennis-racket effects [25] are taken into account. The circumferentially uniform stiffness (CUS) [26] lay-up configuration that yields lateral bending-vertical bending and twist-extension couplings is applied for the rotary structure [11,27,28]. The governing equations and the boundary conditions are derived via Hamilton's principle.…”