Papers by Keyword: Oscillation

Abstract: The influence of the moving load on suspended monorail was studied. During the movement of suspended carriages were established inertial forces, which lead to the additional monorail curvature. Found the dependence of the maximum dynamic load of the trucks speed along the monorail. Established speed of truck at which load of the monorail is practically static. The dependence of the bending section of the monorail under the influence of moving dynamic forces and the value of dynamic coefficient for suspended monorail track were found.

Abstract: In order to be used as food supplements, materials (medicinal and aromatic plants, other materials containing active principles, etc.) need to be chopped and sorted by size, depending on the field of use: herbal tea, suspensions, tinctures, etc. The paper presents the results of research on the sorting process of some materials containing active principles (yarrow, alfalfa and willow bark) using a sorting machine provided with 2 electro vibrators fitted on each side of the framework within which 3 sieves with a mesh size of: 2.15, 4 and 8 mm are fitted, changing the oscillation regime of the sieves by adjusting the angle of the electro vibrators, in order to identify the optimal sorting regime.

Abstract: Research within the TACR TA02010837 project “A Multi-Purpose Demountable Prefabricated Reinforced Concrete Building System with Controlled Properties of Joints and Potential Repetitive Use” included the design of a prefabricated column system with articulated joints of columns and cross bars and diaphragms elastically embedded in some spans; this system allows the modification of static and dynamic characteristics – stiffness and the load-bearing system’s response to external static and dynamic loading effects and impacts. The article presents partial results of a theoretical and experimental analysis of the behaviour of a frame span with a diaphragm discretely connected by means of rubber bearings and cross bars.

Abstract: This study performed 2D analysis for suspension bridge to predict the bridge superstructure oscillation induced by wind load. Previous studies exhibited that a large torsional mode can be generated by continuous vertical modes in suspension bridge. However, the previous studies did not consider torsional resistance of the superstructure and unrealistic results were shown as wind speeds increasing. Therefore, this study developed a new model considering torsional resistances and predicted responses of a suspension bridge. Analysis results exhibited that vertical oscillations were transformed to the torsional oscillations. With varying torsional resistances, vertical responses were stabilized over a time. However, the rotational response amplified at resonance points. Also, it was found that the resonance of the rotational mode depended on the torsional resistance.

Abstract: In this paper we consider the oscillation and spectrum of a class of high order two-term differential operators. Using the oscillation and non-oscillation criteria of related equation obtained here, we describe some spectral information of differential operators. In particular, the conditions which guarantee that any self-adjoint extension of differential operators has spectrum discrete and bounded below are given.

Abstract: The instability and dynamics behavior of a cantilevered thin-elastic plate with large deformation subjected to axial flow is studied numerically. The structural dynamics equation is discretized by isoparametric displacement-based finite, and the motion of a continuous fluid domain is governed by two-dimensional incompressible viscous Navier-Stokes equations, which discretized by finite volume method. The two-dimensional numerical model of two-way fluid-structure coupling is established combined with moving mesh technology, realizing the interaction of thin-elastic plate and axial fluid. Firstly, under given different flow velocity, the stability of limit-cycle oscillations has been studied through Hopf bifurcation, time trace, vibration responses. Secondly, the fluid domain features are analyzed qualitatively by separately comparing with vorticity under given different flow velocity, and cloud diagram of pressure and velocity are also analyzed at U=3.6m/s.

Abstract: In this paper, we provide the criterion of existence of oscillation solutions to the following second order stochastic difference equation (please see in body part)

Abstract: With good repeatability and simple structure, transmission line pulse (TLP) has been used in immunity test of integrated circuit and printed circuit board. A TLP generator is first manufactured and its output waveform is presented. By using wavelet transform, the waveform is denoised and discriminated to components inherent to system function and parasitic parameters. Frequency spectrum changed with time is also obtained by continuous wavelet transform of complex morlet. Decomposed damping oscillation component and high frequency component in instant frequency spectrum show influence of inductance in circuit on the waveform. Improvement of rising time and overshoot is achieved by change of probe connection with shorter grounding line.

Abstract: This paper discusses a class of unstablesecond order neutral differential equations with positiveand negative coeffcients. Sufficient conditions for all bounded solutions of the equations to be oscillatory areobtained.

Abstract: A class of general nonlinear neutral differential equations for its special cases are discussed. sufficient conditionsfor all solutionsof the equations to be oscillatory are obtained. It can be treated in the extreme limite theorem.