Papers by Keyword: Vibration Mode

Abstract: In order to optimize the basalt-fiber-concrete mixtures compositions, as well as to determine the most effective technological parameters in vibrocentrifugation technology, a compositional plan of experiments has been developed. Within the framework of the proposed experimental setup for creating vibrocentrifuged samples of annular cross-section with a variatropic structure, the following technological factors have been identified and considered: the clamps’ technological protrusions height; vibration mode (asynchronous - A, punctuational - P, synchronous - S). The clamps’ technological protrusions height varied within the following limits: 2.5 mm; 5 mm; 10 mm. The change in the percentage of coarse aggregate fractions and the percentage of fiber reinforcement was considered as the prescription factors. The percentage of fiber reinforcement varied within the following limits: 3.5%; four %; 4.5%. The content of fraction 5-10 in relation to fraction 10-20 varied within the following limits: 40 %; 50 %; 60 %. Based on the results obtained, it can be concluded that the most effective will be the use of clamps with a height of technological protrusions equal to 5 mm, with an alternating vibration mode, a percentage of fiber reinforcement equal to 4, and with a content of fractions of 5-10 mm and 10-20 mm equal percentage.

Abstract: Taking efficient pumping-unit linear motor as the research object in this paper, SOLIDWORK has been used to establish 3D model and analyze multi-physics of the efficient pumping-unit linear motor, including vibration mode, stress analysis and the analysis of temperature field. Through the simulation analysis, getting efficient pumping unit linear motor of the top five order vibration frequency, pressure distribution and temperature distribution, theoretical references are provided for the analysis of the efficient pumping-unit linear motor. The innovation of the article is in coupling analysis of multi-physics.

Abstract: With the development of transportation, more and more long-span floating system steel truss-stiffened cable-stayed bridges have been built. Due to the non-restraint in longitudinal direction, this kind of bridges possess very superior performance in the dissipation of vibration energy. On account of the characteristics above, the paper intends to discuss the dynamic behavior of this type of bridges. Based on a real structure design, the numerical simulation procedure of the vibration has been introduced. According to a series of assumptions, the dynamic 3D FEM model of the bridge is established firstly. Thereafter, the vibration characteristics of the model are evaluated. Results show that the longitudinal stiffness is relatively small in comparison to the torsional stiffness. The 1st order mode is longitudinal floatation of girders and pylons. But overall the bridge is still rather flexible.

Abstract: The underwater glider is a new type of autonomous underwater vehicle driven by buoyancy. The glider hydrofoil is the key driving element of the glider, it works under complex alternative load and determines the safety of navigation of the underwater glider. This paper takes the hydrofoil as the research object, a finite element model of hydrofoil has been established and the dynamic load of hydrofoil has been calculated. Finite element model analysis was conducted to the glider hydrofoil in free and restrained states, and the preceding few orders natural frequency of the glider hydrofoil and the corresponding vibration model and the vibration amplitude in the conditions were conducted respectively. The dangerous area of the glider hydrofoil was found out, which could provide data for optimal dynamic design and dynamic modification of hydrofoil.

Abstract: It has been easy to deformation for car doors which opened and closed parts of a vehicle to withstanding various loads. Not only affected the car's appearance and degree of opening, but also deformation increased when subjected to collision. Therefore, it is great significance to internal board dynamic design of the car safety through dynamic analysis of the key pieces of the door to access to inner door panel features. In the paper, the method based on the calculation mode is proposed to analyses the dynamic characteristic of the car doors. The modal analysis of the inner door panel is respectively the inner door panel and the circumference of the fixed constraint on the free-state. The modal parameters and the mode shapes are calculated through finite element analysis. According to these FEM calculating results, the low-order natural frequencies and modal vibration shapes of the inner door panel are computed and identified on the two states. On the basis of these modal parameters, the faults of the inner door panel are shown and its weak points of the design are illustrated. The reason for deformation is analyzed and relevant measures employed to reduce faults are proposed. These improvements can guarantee the normal work of the tool cutter.

Abstract: As the expanding applications of linear ultrasonic motor, the demand for high-thrust linear ultrasonic motor in the aerospace and industrial robots is growing. Consequently, for a high-thrust linear motor, it’s stator model was established according to the actual structure of the motor stator and was also analyzed of the motor stator modal by the finite element method. The results show that the inherent frequency of vibration for the motor stator increases with the order, and corresponds with the vibration mode, by which was realized to work for the linear ultrasonic motor.

Abstract: Through the condition analysis of the drill rod during the mining horizontal drilling for gas drainage, the finite element model of the drill rod lateral vibration is established. The drill rod lateral vibration is related to the diameter and length of the drill rod. With the increase of the diameter of the drill rod, the natural frequency of the lateral vibration of the drill rod increases constantly. The increasing amplitude of the natural frequency at the larger diameter of the drill rod is larger than that at the smaller diameter. When the drill rod is longer, the natural frequency of the lateral vibration of the drill rod is lower. From the modal images of the drill rod, the lateral vibration of the drill rod is similar to the sine curve. During the horizontal drilling in coal seam, the drill rod contact and impact with the hole wall which will bring about the fatigue fault of the drill rod and the collapse of the hole wall.

Abstract: Based on the finite element theory, an analysis about the changing of rotor vibration mode of the wind turbine with and without rudder at static state, and a research was carried out to study the impact of the rudder on wind turbine vibration frequency during operation condition of a small horizontal axis wind turbine by using Ansys Workbench. The result showed that, rudder vibration mode was the coupling of rudder vibration mode and first order anti-symmetric vibration mode of rotor. With the increasing of rotating speed, wind turbine vibration frequency increased because of the stiffening effect caused by centrifugal force, and the difference of first order anti-symmetric vibration frequency and symmetric vibration frequency was decrease which was caused by the aerodynamic force. At the same time, the changing of the external load had no effect on the vibration frequency of rudder, the reason of that was counterweight of the rudder. When the rotor speed was in the resonance region, rudder vibration frequency was equal to first order anti-symmetric vibration frequency at the rotating speed n=10.91Hz, an obviously resonance phenomenon occurred. The related research could provide some theoretical guidance for the design of small wind turbine rudder.

Abstract: In this paper, Finite Element Technology is applied to study the vibration state of violin sounding box using numerical simulation. By means of geometric modeling for the complicated shape of violin sounding box and Finite Element Analysis, the structural parameters of violin box, including thickness of violin plate, height and distribution and change of the shape of arch in front plate geometry, status of bass bar and sound-post etc, are investigated for their influence on vibration patterns and frequency response of violin box. Experiment is carried out for measuring the frequencies responses of violin box to verify the results of the Finite Element Analysis. This research provides a feasible way of theories for violin makers to improve the vibration characteristics of violin.

Abstract: In recent years, with the development of high-speed rail in China,bridge has a higher proportion in the lines. Every year earthquake occurs many times accidentally in China. In order to ensure the target performance of bridges under earthquake action, we need to be based on the seismic analysis. Only have a deep knowledge of seismic effect discipline, can we enable to guide seismic design economically and reasonably and achieve predetermined target performance. Our study shows that the main vibration mode is a combination of the longitudinal or lateral translation or the revolution around Z axis. Under high-level earthquake, the maximal displacements of side piers and the fixed pier are larger, the maximal longitudinal pier shaft moment of the fixed pier (No.3) or No.5 pier in lateral direction is larger. But the value that exceeds the yield moment is small, which indicates that the development of plasticity is little. The longitudinal shear force of the bearings on the same pier are the same, bearings fixed longitudinally own the largest value. Even bearings whose lateral directions are fixed on the same pier own larger forces. Seen from average maximum values of bearings, all bearings are at the second stage, meeting the requirements that we don’t need to repair or slightly repair the bridge to make it act normally once after an earthquake.