Dynamic response of coupled shaft torsion and blade bending in rotor blade system

Shao

Advances in Mechanical Engineering

et al. 2018

Marine power rear transmission system is a constant power system under specific working condition, which relies on alternating meshing gears to transfer the movement and torque. It is difficult to accurately determine the actual thermal stress and thermal deformation for time-varying distribution using the traditional methods. Elastic structural mechanics modeling and method details of thermal expansion deformation are presented and analyzed. Both the actual reflection thermoelastic contact condition for meshing gears and the coupling effect results of the practical loading process of marine power rear transmission system carried out on alternating meshing gear surfaces are also detailed. In this article, the changes in gear meshing angles of several key meshing positions are presented. The 16 meshing positions of contact stresses and loaded deformation approach are analytically evaluated in terms of the rotation range of driving spur gear (35°) and driving helical gear (36°). The purpose of this study is to confirm the significant stress concentration areas of gear meshing in and meshing out and to obtain that the deformation amounts of gear meshing impact positions within selected zones. The aim of this article is to reach gear deformation on the basis of theoretical conception.

Section: Introductionmentioning

confidence: 99%

Thermomechanical coupled contact analysis of alternating meshing gear teeth surfaces for marine power rear transmission system considering thermal expansion deformation

Shao

Advances in Mechanical Engineering

et al. 2018

“…A coupled system with a pre-twisted blade attached to a rigid disk was modeled and investigated by Lee et al [46] to capture its dynamic characteristics by taking advantage of Lagrange equation and Rayleigh-Ritz method. The study described in this paper highlights the vibration reduction for the blisk by depositing a hard coating on the blades, and is organized as follows: In Section 2, the theoretical analysis of the blisk with hard-coated blades is conducted by using the complex-valued modulus theory together with the Rayleigh-Ritz method, such as the establishment of an analytical model, the derivation of the equivalent parameters for hard-coated blades, and the derivation of natural frequencies, loss factors, and frequency response functions.…”

Section: Description For the Analytical Modelmentioning

confidence: 99%

“…Thus, the number of components, mass, and abrasive wear of the blisk were effectively reduced, and the aerodynamic performance and method, rotating pre-twisted tapered blades made of functionally-graded materials are modeled with various dimensionless geometric parameters and analyzed to solve its vibration characteristics by Yutaek and Hong [45]. A coupled system with a pre-twisted blade attached to a rigid disk was modeled and investigated by Lee et al [46] to capture its dynamic characteristics by taking advantage of Lagrange equation and Rayleigh-Ritz method.…”

Section: Introductionmentioning

confidence: 99%

Vibration Characteristics and Damping Analysis of the Blisk-Deposited Hard Coating Using the Rayleigh-Ritz Method

Gao

Sun

2017

Coatings

Abstract:For the purpose of improving the working reliability of the blisk (integrally-bladed disk) under severe environment, a passive vibration reduction method by depositing a hard coating on both sides of blades is developed and then investigated systematically. Firstly, an analytical model of the blisk-deposited hard coating is taken into account. Secondly, by using the Oberst beam theory and axial symmetry property, the composite hard-coated blade is equivalent to a special homogeneous blade possessing the equivalent material parameters. Then, energy equations of the blisk with hard-coated blades are derived by using the complex-valued modulus, and then substituted into the Lagrange equations. Additionally, eigenvalue equations of the blisk with hard-coated blades are acquired by taking advantage of Rayleigh-Ritz method, and its natural characteristics are obtained subsequently. Further, the frequency response functions of the blisk with hard-coated blades are formulated by using proportional damping to achieve its damping matrix. Finally, a stainless-steel blisk with deposited NiCoCrAlY + YSZ hard coating on both sides of the blades is chosen as the study case to conduct numerical calculations, and the results are compared with those obtained by experimental tests in terms of natural frequencies and mode shapes. The variation of natural frequencies, modal loss factors and frequency response functions of the blisk generated by hard coating are studied, respectively, and the influence of the coating thickness on the damping capacity are further discussed.

“…Yao et al [8] investigated the nonlinear dynamic characteristics of the rotating blade and used the bifurcation diagram, phase portrait, and power spectrum to demonstrate that periodic motions and chaotic motions occur in nonlinear vibrations of the rotating blade under certain conditions. Lee et al [9] developed a computational model for the dynamic characteristics of a rotor-blade system. The dynamic characteristics of the system for various system parameters were obtained.…”

Section: Introductionmentioning

confidence: 99%

Study on the Nonlinear Characteristics of a Rotating Flexible Blade with Dovetail Interface Feature

Shen

Zhong

et al. 2018

Shock and Vibration

A dynamic model is proposed in this paper for analyzing the nonlinear characteristics of a flexible blade. The dynamical equation of motion for a rotational flexible blade in a centrifugal force field is established based on the finite element method. A macro-stickslip mechanical model of dry friction is established to simulate the constraint condition of the flexible blade. The combined motion of the external excitation and friction produces a piecewise linear vibration which is actually nonlinear. The numerical integration method is employed to calculate the vibration reduction characteristics of the nonlinear constrained rotating blade. The results show that the nonlinear dry friction force produced by the dovetail interface plays an important role in vibration reduction. And the effect of dry friction vibration reduction is significant when the rotating speed is slow or the friction coefficient is small. Besides, the magnitude of external excitation also has a great impact on the state of the friction. Therefore, some relevant experimental researches should be done in the future.