About the Stabilization of Anisotropic Cylindrical Shell With Elastic Filling

2000 ◽  
Author(s):  
Vladimir Sarkisyan ◽  
Sarkis Sarkisyan
Keyword(s):  
Differential Equation ◽  
Cylindrical Shell ◽  
Mechanical System ◽  
Mechanical Systems ◽  
Elastic Base ◽  
Optimal Stabilization ◽  
Convergence Of Series ◽  
Symmetric Kernel ◽  
The Given ◽  
Anisotropic Cylindrical Shell

Abstract The problems about the optimal stabilization of mechanical system of a potency of continuum have the large interest, both theoretical and practical. The solution of such problems is reduced to the nonhomogeneous integro-differential equation with the symmetric kernel. The essential results in the solution of problems of the optimum stabilization for mechanical systems of a potency of continuum are obtained [4], [5]. In work [4,5,6] the convergence of series of solutions and the finiteness of a target functional is proved uniformly. Solved a numerous problems of the optimal stabilization of vibrations of plates and rather slanting shells. In various statements the problem of the optimal stabilization for anisotropic cylindrical shells are solved in [6] etc. The given work is attempt to fill in a gap the problems of the stabilization by the problems about the optimal stabilization of vibrations of shells with filling, where the filling as Winkler’s elastic base, and for filling of Vlasov’s model [3] is considered.

scholarly journals On the integrable deformations of a system related to the motion of two vortices in an ideal incompressible fluid

2019 ◽  
Vol 29 ◽  
pp. 01015 ◽  
Author(s):  
Cristian Lăzureanu ◽  
Ciprian Hedrea ◽  
Camelia Petrişor
Keyword(s):  
Incompressible Fluid ◽  
Mechanical System ◽  
Integrable Systems ◽  
Degrees Of Freedom ◽  
Mechanical Systems ◽  
Ideal Incompressible Fluid ◽  
First Integrals ◽  
Integrable Deformation ◽  
Integrable Deformations ◽  
The Given

Altering the first integrals of an integrable system integrable deformations of the given system are obtained. These integrable deformations are also integrable systems, and they generalize the initial system. In this paper we give a method to construct integrable deformations of maximally superintegrable Hamiltonian mechanical systems with two degrees of freedom. An integrable deformation of a maximally superintegrable Hamiltonian mechanical system preserves the number of first integrals, but is not a Hamiltonian mechanical system, generally. We construct integrable deformations of the maximally superintegrable Hamiltonian mechanical system that describes the motion of two vortices in an ideal incompressible fluid, and we show that some of these integrable deformations are Hamiltonian mechanical systems too.

On the Steady State Motions Control Problem for Mechanical Systems with Relay Controllers

2021 ◽  
Vol 1 (1) ◽  
pp. 48-55
Author(s):  
Aleksandr Andreev ◽  
Olga Peregudova
Keyword(s):  
Differential Equation ◽  
Steady State ◽  
Asymptotic Stability ◽  
Control Problem ◽  
Mechanical System ◽  
Lyapunov Functions ◽  
Robot Manipulator ◽  
Mechanical Systems ◽  
Stabilization Problem ◽  
Stability Of The Solution

The paper presents the solution to the stabilization problem of steady state motions for a holonomic mechanical system by using relay controllers. This solution is achieved by proving new theorems on the asymptotic stability of the solution to a differential equation with a discontinuous right-hand side. The novelty of the theorems is based on the limiting inclusions construction and the use of semidefinite Lyapunov functions. As an example, the stabilization problem of steady-state motion for a five-link robot manipulator is solved by using relay controller.

scholarly journals Interaction of a Cylindrical Tank Bottom with an Elastic Foundation

2018 ◽  
Vol 251 ◽  
pp. 04020
Author(s):  
Andrey Leontyev ◽  
Avgustina Astakhova ◽  
Mikhail Maksimov
Keyword(s):  
Cylindrical Shell ◽  
Circular Cylindrical Shell ◽  
Rectangular Cross Section ◽  
Slope Angle ◽  
Relative Length ◽  
Longitudinal Axis ◽  
External Action ◽  
Elastic Base ◽  
Vertical Walls ◽  
The Given

The problem of static analysis of a circular cylindrical shell located on the elastic base of the Winkler and reinforced by longitudinal ribs is considered. The stiffeners have a rectangular cross section. The external action is represented by forces evenly distributed along the longitudinal axis, acting on the ribs from the upper structure. It is assumed that at the ends of the shell there are flat vertical walls, which give the contour absolute rigidity in the transverse direction and do not interfere with the longitudinal movement of the shell points. The General moment theory of a circular cylindrical shell is used to solve the problem. A computer program has been developed to implement the proposed algorithm. With the help of the program, a number of examples of calculation are made In the given examples, the influence of such factors as the relative length and thickness, the slope angle of the solution shell, the relative stiffness of the onboard elements on the stress state of the shell is analyzed.

SYMBOLIC REPRESENTATION OF FORCED OSCILLATIONS OF BRANCHED MECHANICAL SYSTEMS

2021 ◽  
pp. 118-130
Author(s):  
I.P. Popov ◽  
Keyword(s):  
Differential Equation ◽  
Differential Equations ◽  
Mechanical System ◽  
Degrees Of Freedom ◽  
Mechanical Systems ◽  
Time Instant ◽  
Forced Oscillations ◽  
Parallel Connections ◽  
Clear Idea ◽  
The Relationship

A calculation of dynamics of a mechanical system with n degrees of freedom, including inert bodies and elastic and damping elements, involves the derivation and integration of a system of n second-order differential equations, which are reduced to a differential equation of 2n order. An increase in the degree of freedom of the mechanical system by one increases the order of the resulting differential equation by two. The solution of higher-order differential equations is rather cumbersome and time-consuming. Integration of equations is proposed to be replaced with rather simpler algebraic methods. A number of relevant theorems that relate both active and reactive parameters of mechanical systems in the series and parallel connection of mechanical power consumers are proved. Using parallel-series and series-parallel connections as an example, the calculation methods for branched mechanical systems with any number of degrees of freedom, based on the use of symbolic or complex representation of forced harmonic oscillations, are shown. The phase relationships determining loading conditions and a possibility of its artificial change are considered. The vector diagrams of the amplitudes of forces, velocities and their components in a complex plane at a zero time instant are presented, which give a complete and clear idea of the relationship between these quantities.

CONTINUOUS TUNING OF SHIP PROPULSION SYSTEM BY MEANS OF PNEUMATIC TUNER OF TORSIONAL OSCILLATION

2021 ◽  
Vol 158 (A3) ◽  
Author(s):  
J Homišin ◽  
P Kaššay ◽  
M Puškár ◽  
R Grega ◽  
J Krajňák ◽  
...  
Keyword(s):  
Mechanical System ◽  
Dynamic Properties ◽  
Torsional Oscillation ◽  
Self Regulation ◽  
Mechanical Systems ◽  
New Method ◽  
Driving Mechanism ◽  
Optimal Tuning ◽  
Continuous Tuning ◽  
The Given

Mechanical system drives consist of driving machines and gearing mechanisms interconnected by shafts and couplings. In terms of dynamics it is possible to say that every driving mechanism is able to oscillate. Especially piston devices can create excessive torsional oscillation, vibrations, as well as noise. Important task of a designer is to reduce torsional oscillation in mechanical systems. Presently this problem is mainly solved by the flexible shaft couplings that are selected with regard to the dynamic properties of the given system. It means that every torsional oscillating mechanical system needs to be suitably tuned. The aim of this paper is to present the possibilities of controlling of dangerous torsional oscillations of the mechanical systems by the means of new method, i.e. its optimal tuning by means of the pneumatic coupling with self-regulation, which were developed by us.

Difference Schemes for Nonlinear BVPS on the Semiaxis

2007 ◽  
Vol 7 (1) ◽  
pp. 25-47 ◽  
Author(s):  
I.P. Gavrilyuk ◽  
M. Hermann ◽  
M.V. Kutniv ◽  
V.L. Makarov
Keyword(s):  
Differential Equation ◽  
Exact Solution ◽  
Boundary Value Problem ◽  
Difference Scheme ◽  
Adaptive Algorithm ◽  
Order Differential Equation ◽  
Constructive Method ◽  
Numerical Examples ◽  
Exact Difference ◽  
The Given

Abstract The scalar boundary value problem (BVP) for a nonlinear second order differential equation on the semiaxis is considered. Under some natural assumptions it is shown that on an arbitrary finite grid there exists a unique three-point exact difference scheme (EDS), i.e., a difference scheme whose solution coincides with the projection of the exact solution of the given differential equation onto the underlying grid. A constructive method is proposed to derive from the EDS a so-called truncated difference scheme (n-TDS) of rank n, where n is a freely selectable natural number. The n-TDS is the basis for a new adaptive algorithm which has all the advantages known from the modern IVP-solvers. Numerical examples are given which illustrate the theorems presented in the paper and demonstrate the reliability of the new algorithm.

The Control of Vibration Transmissibility Using an Electrodynamic Actuator –Close-Loop Solution

2013 ◽  
Vol 436 ◽  
pp. 166-173
Author(s):  
A. Mihaela Mîţiu ◽  
Daniel Constantin Comeagă ◽  
Octavian G. Donţu
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Mechanical System ◽  
Closed Loop ◽  
Mechanical Systems ◽  
Vibration Transmissibility ◽  
Technical Solutions ◽  
The Mathematical Model

In this paper are presented some aspects of transmissibility control of mechanical systems with 1 DOF so that the effects of vibration on their action to be minimized. Some technical solutions that can be used for this purpose is analyzed. Starting from the mathematical model of an electro-mechanical system with 1 DOF, are identified the parameters which influence the effectiveness of the transmissibility control system using an electrodynamic actuator who work in "closed loop".

Controlled Arming of Mechanical Systems Embedded into Embarked Electrical Systems

2014 ◽  
Vol 555 ◽  
pp. 209-216
Author(s):  
Gheorghe Negru
Keyword(s):  
Kalman Filter ◽  
Mechanical System ◽  
High Speed ◽  
Mechanical Systems ◽  
Electrical Systems ◽  
General Motion

The paper presents an application of the Kalman filter to achieve the controlled arming of mechanical system embedded into embarked electrical systems (FMES). The solution of FMES which contain mechanical subsystems electronically controlled could significantly reduce the influence, on their functioning, of the general motion of high speed object (HSO) .

The Method for Determining the Vibration-Damping Elements for the Mechanical System to Obtain the Desired Amplitude Value

2014 ◽  
Vol 657 ◽  
pp. 644-648 ◽  
Author(s):  
Andrzej Dymarek ◽  
Tomasz Dzitkowski
Keyword(s):  
Mechanical System ◽  
Dynamic Characteristics ◽  
Vibration Reduction ◽  
Mechanical Systems ◽  
Vibration Damping ◽  
Displacement Velocity ◽  
Synthesis Methods ◽  
Resonance Frequencies

The paper presents the use of synthesis methods to determine the parameters of passive vibration reduction in mechanical systems. Passive vibration reduction in a system is enabled by units called dampers whose values are determined on the basis of the method formulated and formalized by the authors. The essence of the method are, established at the beginning of a task, dynamic characteristics in the form of the resonance and anti-resonance frequencies, and amplitudes of displacement, velocity or acceleration of vibration.

An Inverse Inviscid Method for the Design of Quasi-Three-Dimensional Turbomachinery Cascades

1993 ◽  
Vol 115 (1) ◽  
pp. 121-127 ◽  
Author(s):  
E. Bonataki ◽  
P. Chaviaropoulos ◽  
K. D. Papailiou
Keyword(s):  
Differential Equation ◽  
Three Dimensional ◽  
Test Cases ◽  
Elliptic Type ◽  
Flow Angle ◽  
Blade Shape ◽  
Closure Conditions ◽  
Type Boundary ◽  
Absolute Frame ◽  
The Given

The calculation of the blade shape, when the desired velocity distribution is imposed, has been the object of numerous investigations in the past. The object of this paper is to present a new method suitable for the design of turbomachinery stator and rotor blade sections, lying on an arbitrary axisymmetric stream-surface with varying streamtube width. The flow is considered irrotational in the absolute frame of reference and compressible. The given data are the streamtube geometry, the number of blades, the inlet flow conditions and the suction and pressure side velocity distributions as functions of the normalized arc-length. The output of the computation is the blade shape that satisfies the above data. The method solves an elliptic type partial differential equation for the velocity modulus with Dirichlet and periodic type boundary conditions on the (potential function, stream function)-plane (Φ, Ψ). The flow angle field is subsequently calculated solving an ordinary differential equation along the iso-Φ or iso-Ψ lines. The blade coordinates are, finally, computed by numerical integration. A set of closure conditions has been developed and discussed in the paper. The method is validated on several test cases and a discussion is held concerning its application and limitations.

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