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Dynamic analysis of three-mass vibratory system with twin crank-slider excitation mechanism

Korendiy Vitaliy, Gursky Volodymyr, Krot Pavlo, Kachur Oleksandr

Vibrations in Physical Systems

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2023

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Vol. 34, nr 2

art. no. 2023226

EN

The paper studies the dynamic behavior of the vibratory sieving conveyor equipped with the twin crank-slider excitation mechanism. The main purpose of this research consists in substantiating the possibilities of implementing the improved drive for providing the controllable vibration parameters of the working member (conveying tray, sieve, etc.) in accordance with the specific technological requirements set for different materials to be sieved and conveyed. In order to reach the goal set above, the following objectives are established: analyzing the design peculiarities of the vibratory sieving conveyor; deriving the mathematical model describing the conveyor’s oscillatory system dynamic behavior; studying the system kinematic, dynamic, and power characteristics. The system motion is described using the Lagrange-d’Alembert principle, and the numerical modeling is carried out in the Mathematica software with the help of the Runge-Kutta methods. The influence of the vibratory system's geometrical parameters on the motion conditions of the conveyor’s working member (conveying tray and sieve) is analyzed.

2

Consideration of the uncertainty in the dimensioning of a gearbox of a wind turbine

Trabelsi Hassen, Guizani Amir, Barkallah Maher, Hammadi Moncef, Hadrich Ayman

Journal of Theoretical and Applied Mechanics

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2021

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Vol. 59 nr 1

67--79

EN

The paper deals with the design approach of a subdefinite mechatronic system and focuses on the sizing stage of a gearbox of a wind turbine based on the interval computation method. Indeed, gearbox design variables are expressed by intervals to take into account the uncertainty in the estimation of these parameters. The application of the interval computation method allows minimizing the number of simulations and enables obtaining a set of solutions instead of a single one. The dynamic behavior of the gearbox is obtained using the finite element method. The challenge here is to get convergent results with intervals that reflect the efficiency of the applied method. Thus, several mathematical formulations have been tested in static study and evaluated in the case of a truss. Then the interval computation method was used to simulate the behavior of the wind turbine gearbox.

3

Numerical study of dynamic behaviors of concrete under various strain rates

An H. M., Liu L.

Archives of Civil Engineering

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2019

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Vol. 65, nr 4

21--36

EN

As the dynamic behavior of the concrete is different from that under static load, this research focuses on the study of dynamic responses of concrete by simulating the split Hopkinson pressure bar (SHPB) test. Finite element code LS-DYNA is used for modeling the dynamic behaviors of concrete. Three continuous models are reviewed and the Holmquist-Johnson-Cook model (HJC) is introduced in detail. The HJC model which has been implemented in LS-DYNA is used to represent the concrete properties. The SHPB test model is established and a few stress waves are applied to the incident bar to simulate the dynamic concrete behaviors. The stress-strain curves are obtained. The stress distributions are analyzed. The crack initiation and propagation process are described. It is concluded that: the HJC model can modeling the entire process of the fracture initiation and fragmentation; the compressive of the concrete is significantly influenced by the strain rates.