Aeroelastic stability analysis and optimization studies of rotating tapered composite sandwich blade with magnetorheological elastomer core

Rotating sandwich blades with viscoelastic smart material cores are known for their excellent vibration and shock absorption characteristics. The present paper deals with the dynamic analysis and aeroelastic instability studies of rotating tapered composite sandwich blade with magnetorheological elastomer (MRE) core in the presence of non-conservative axial forces within the supersonic flow regime. Non-uniform rotating sandwich blade with four-ply carbon-epoxy-laminated face sheets and MR core is modeled using Timoshenko beam theory. Vibration behavior and aeroelastic studies of the tapered rotating blade are conducted using finite element method for different MR core materials. The results of the preliminary analysis are validated with an experimental study and using three-dimensional finite element solution. Furthermore, using the present model, the effects of the magnetic field intensity, taper ratio, thickness ratio of MR layer and rotating speed on critical aerodynamic pressure and damping are studied. The dynamic characteristics and instability states of the blade in combined action of tip axial load, magnetoelastic force, centrifugal load and aerodynamic pressure are obtained. The most significant parameters affecting the critical aerodynamic pressure and loss factor are identified, and a neural network regression model is developed to map the relationship between input and output parameters. The optimal input parameters are predicted using surrogate model-based genetic algorithm optimization procedure for improving the critical aerodynamic pressure and loss factor.