Dynamic stiffness method

This study presents the continuous element formulation for analyzing the dynamic behavior of ring-stiffened cylindrical shells made of FGM material. Based on the solutions of the shell differential equations, the dynamic stiffness matrix is calculated. A procedure to assembly cylindrical and annular shells is introduced in order to compute the natural vibrational frequencies of FGM ring-stiffened cylindrical shells.

9p dathienlang1012 03-05-2024 1 0   Download

This research presents Dynamic Stiffness formulations for studying dynamic behavior of composite inner/outer ring-stiffened cylindrical shells. The continuous elements investigated in this paper are cylindrical and ring elements. Base on dynamic stiffness matrix of the above elements, an assembling procedure is proposed to solve the problem of complex composite inner/outer ring-stiffened cylindrical shells.

9p dathienlang1012 03-05-2024 1 0   Download

This paper analyses free vibrations of framed nanostructures made of Functionally Graded Material (FGM) based on the Nonlocal Elastic Theory (NET) and the Dynamic Stiffness Method (DSM). FGM characteristics vary nonlinearly throughout the height of the beam element.

19p viisac 15-09-2023 11 3   Download

This paper presents the finite element algorithm and results on dynamic response of cracked plate structure on elastic foundation subjected to moving oscillator with a constant velocity and any motion orbit. The response to a single moving oscillator is first investigated and then the effects of crack, velocity, elastic foundation stiffness, and stiffness of the spring of moving oscillator are studied.

7p viannee 04-08-2023 4 3   Download

In this paper, an isolator is introduced for isolating low frequency vibrations. Then, Normal form method is used to predict the curve of vibration transmissibility of this isolator. This paper is organized as follows. The mathematical model of system is presented in section.

6p vidoctorstrange 06-05-2023 7 2   Download

Frequency analysis of a functionally graded beam bonded by a piezoelectric layer is carried out by using the dynamic stiffness method. First, governing equations are conducted for FGM beam element with a piezoelectric layer based on the Timoshenko beam theory and power law of material grading.

5p viwendy2711 05-10-2021 13 1   Download

This paper presents a new continuous element model for studying the dynamic behavior of complex tubes composed by cylindrical shell, annular plate and conical shell which are widely used in automobile exhausts, sewer pipes and pipelines. Based on the analytical solutions of the system of differential equations for cylinders, cones and annular plates, the dynamic stiffness matrix for complex composite tubes has been established and assembled.

6p cothumenhmong11 10-05-2021 17 1   Download

This research presents a continuous element model for solving vibration problems of FG stepped truncated conical shells having various material properties and surrounded by Pasternak foundations. Based on the First Order Shear Deformation Theory (FSDT) and the equations of the FGM conical shells, the dynamic stiffness matrix is obtained for each segment of the shell having constant thickness.

20p nguaconbaynhay11 07-04-2021 16 1   Download

This paper presented a method to reduce the torsional vibration of a shaft system with dynamic vibration absorber (DVA). A theoretical method was introduced to determine optimal parameters of the DVA, which included spring stiffness, viscous coefficient of damper, mass moment of inertia of the absorber, number, and radial position of springs and dampers. First, system equations of motion of the shaft and the DVA were elaborated using Finite Element method (FEM) and solved by Runge-Kutta algorithm to find the torsional vibration response.

6p chauchaungayxua11 23-03-2021 12 1   Download

In this paper, dynamic stiffness model of a cracked frame structure that represents a planar tower crane is established in an explicit form based on general solution of cracked 2Dbeam element vibration. The crack is modeled by a pair of equivalent springs of stiffness calculated from the crack depth. An explicit form of frequency equation is first established and then solved for numerical sensitivity analysis of natural frequencies of the structure to cracks. An experimental study is accomplished to validate the theoretical development.

13p cothumenhmong9 04-01-2021 14 1   Download

Dynamic instability of thin rectangular plates subjected to uniform in-plane harmonic compressive load applied along two opposite edges are investigated in this paper. The dynamic stiffness method (DSM), as a consequence the dynamic stiffness matrices, is used to analyze the free vibration, the static stability, and dynamic instability of thin plates under different boundary conditions.

11p vijakarta2711 09-06-2020 15 3   Download

This article studies the free vibration of composite ring-stiffened cylindrical shells by the continuous element method (CEM). The dynamic stiffness matrix (DSM) of the studied structure has been constructed based on the analytical solutions of the governing equations of motion for composite cylindrical shells and annular plates.

16p abcxyz123_02 03-03-2020 11 0   Download

In an active magnetic bearing (AMB) system, the rotor always rotates at extremely high speed which always accompany with huge vibrations and noises. Most of the former researches associated with reducing the rotor vibrations are mainly focused on the control methods of AMB.

8p vivalletta2711 11-01-2020 13 2   Download

The paper deals with a velocity control problem of a three-mass system. The equations of motion of the system with limited shaft stiffness and damping is derived via d’Alembert principle. Based on the system dynamics, an active disturbance rejection control is developed for the system via a support of an extended state observer.

6p viminotaur2711 29-10-2019 20 0   Download

A new method determining the equivalent dynamic parameters such as stiffness, vibrating mass, and air damping factor in motion direction of shuttle (i.e. in ydirection) is proposed, thence the differential motion equation of shuttle is established and solved to achieve a typical displacement formula.

10p danhdanh11 09-01-2019 22 2   Download

The vibration frequencies for different filling ratios of cylindrical shells are obtained and compared with existing experimental and theoretical results which indicate that the fluid filling can reduce significantly the natural frequencies of studied cylindrical shells. Detailed parametric analysis is carried out to show the effects of some geometrical and material parameters on the natural frequencies of orthotropic cylindrical shells.

14p thienthanquydu 21-10-2018 30 1   Download

This research presents a new model for vibration analysis of thick laminated plates on a non-homogeneous elastic foundation by the Dynamic Stiffness Method (DSM). The non-homogeneous foundation consists of multi-segment Winkler-type and Pasternak-type elastic foundation. The Dynamic Stiffness Matrices using the First Shear Deformation Theory (FSDT) are constructed for cross-ply thick composite plates.

20p thienthanquydu 19-10-2018 39 2   Download

In this paper, natural frequency of completely fluid-filled composite circular cylindrical shells on Winkler and Pasternak elastic foundations are studied. The Dynamic Stiffness Method is employed to solve the cylindrical shell problem. Natural frequencies of fluid-filled cylindrical shells based on elastic foundations are evaluated. It is observed that frequencies are strongly affected when a cylindrical shell is attached with elastic foundations.

5p doctorstrange1 15-06-2018 35 1   Download