In this paper, an enhanced solid finite element formulation for rotor dynamics analysis is presented. The kinematics first defined with a Total Lagrangian in order to account possible centrifugal stiffening effect and its associated pre-stress deformation. novelty of the three-dimensional proposed study then correctly consider inertia due small rotational deformation occurring around pre-stress...

In this paper we further develop the theory of the extended Timoshenko beam model, as first introduced in Part I [5] of this work, with particular emphasis on applications of the model in formation theory [11], [12]. We begin with formal development of the equilibrium equations of static formation theory in the context of the extended Timoshenko model, giving a rigorous discussion of existence,...

The Riesz basis property of the generalized eigenvector system of a Timoshenko beam with boundary feedback is studied. Firstly, two auxiliary operators are introduced, and the Riesz basis property of their eigenvector systems is proved. This property is used to show that the generalized eigenvector system of a Timoshenko beam with some linear boundary feedback forms a Riesz basis in the corresp...

this work deals with effects of asymmetric stiffness on the dynamic behaviour of the rotor system. the analysis is presented through an extended lagrangian hamiltonian mechanics on the asymmetric rotor system, where symmetries are broken in terms of the rotor stiffness. the complete dynamics of asymmetries of rotor system is investigated with a case study. in this work, a mathematical model is ...

Analytical relations between the critical buckling load of a functionally graded material (FGM) Timoshenko beam and that of the corresponding homogeneous Euler–Bernoulli beam subjected to axial compressive load have been derived for clamped–clamped (C–C), simply supported–simply supported (S–S) and clamped–free (C–F) edges. However, no such relation is found for clamped–simply supported (C–S) b...

This study has investigated the influence of journal bearing wear on dynamic behaviour a flexible rotor with central disc. Rotors supported bearings are susceptible to self-excited whirling, leading unstable conditions. Prior knowledge stability limit speed is important avoid excessive vibration rotating machines. For in this paper, were lubricated powder owing high-temperature applications whe...

Timoshenko beam equations with external damping and internal damping terms and forcing terms are investigated, and boundary conditions (end conditions) to be considered are hinged ends (pinned ends), hinged-sliding ends, and sliding ends. Unboundedness of solutions of boundary value problems for Timoshenko beam equations is studied, and it is shown that the magnitude of the displacement of the ...

We consider the dynamical one-dimensional Mindlin-Timoshenko system for beams. We analyze how its controllability properties depend on the modulus of elasticity in shear k. In particular we prove that the exact boundary controllability property of the Kirchhoff system may be obtained as singular limit, as k → ∞, of the partial controllability of a sharp subspace of low frequency components of t...

We present a computational approach for the construction of reducedorder controllers for the Timoshenko beam model. By means of a space discretization of the Timoshenko equations, we obtain a large-scale, finite-dimensional dynamical system, for which we compute an LQG controller for closed-loop stabilization. The solutions of the algebraic Riccati equations characterizing the LQG controller ar...

This paper shows how the so called von Kármán model can be obtained as a singular limit of a modified Mindlin-Timoshenko system when the modulus of elasticity in shear k tends to infinity, provided a regularizing term through a fourth order dispersive operator is added. Introducing damping mechanisms, the authors also show that the energy of solutions for this modified Mindlin-Timoshenko system...