Isogeometric-stepwise vibrational behavior of rotating functionally graded blades with variable thickness at an arbitrary stagger angle subjected to thermal environment. (15th July 2020)

• Record Type: Journal Article
• Authors: Ansari, E.; Setoodeh, A.R.; Rabczuk, T.
• Is Part Of: Composite structures. Volume 244(2020)
• Publication Date: 2020-07-15
• Subjects: Isogeometric analysis -- Turbo-machinery FG blades -- Vibration analysis -- Variable thickness -- Frequency loci veering -- Coriolis effect -- Thermal environment; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2020.112281
• Languages: English
• ISSNs: 0263-8223

Abstract

Highlights: Systematically stepwise analysis (SSA) for vibration of rotating FG blades in thermal environment. Isogeometric analysis is deployed to model the blade geometry and solve the FSDT-based governing equations. Plate modeling with linear and nonlinear thickness variations is considered for rotating FG blades. Symmetric 4-digit NACA airfoils are employed for the vibrational analysis as an important industrial application. The complicated frequency loci veering behavior and the associated mode shifting phenomena are presented. Abstract: A systematically stepwise analysis (SSA) is presented for the free vibration analysis of rotating functionally graded (FG) turbo-machinery blades with linear and non-linear variable thickness operating in thermal environment. The governing equations are extracted by deployment of principle of the virtual work and Hamilton's principle in the context of first-order shear deformation plate theory (FSDT) and the two-dimensional kinematics of the rotating blades. The nonlinear terms of the strain tensor are taking into account to insert the resulted stresses obtained from a pseudo-static analysis. Also, the inertia and Coriolis forces are included in the second step of the vibrational analysis. Eventually, the isogeometric analysis (IGA) as a powerful numerical approach is employed to discretize the resulted governing equations. To exhibit the reliability and efficacy of the IGA, a comprehensive comparative study on the predicted natural frequencies and mode shapes of the FG blades is performed compared with the available solutions in published literatures as well as finite element analysis using ANSYS. In order to assist scientists and engineers during the design, the complicated frequency loci veering behavior and the associated mode shifting phenomena are investigated with precisely predicting the coupling between the in-plane, out of plane and torsional vibration.