Vibration of higher-order-shearable pretwisted rotating composite blades

摘要: Abstract The free and forced vibration of a rotating, pretwisted blade modeled as laminated composite, hollow (single celled), uniform box-beam is studied. structural model includes transverse shear flexibility, restrained warping, centrifugal Coriolis effects. A key element this its ability to satisfy the zero shear–traction requirement on external bounding surfaces. governing system possesses complicated eigenvalue-dependent natural boundary conditions. Hence an extended Galerkin method using admissible functions employed. Free-vibration results obtained for present higher-order shearable are compared with those existing first-order non-shearable models. For data considered, theory provides conservative predictions. This suggests that through-the-thickness variations strains significant should be considered when pursuing non-resonant designs. effect pretwist, while marginal lowest eigenfrequency, substantial higher ones especially lower rotation speeds larger ply angles. combination softening stiffening effects also possible same eigenfrequency pretwist varied. Tailoring studies show enhancement characteristics reveal potential passive mitigation response.