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Earthquakes are violent movements of the Earth’s surface resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. The movements are characterized by rapid variations of direction, speed and acceleration. The present paper analyzes the response of the structures and the behavior of buildings during high-intensity earthquakes. The target areas of the study are Galati and Suceava municipalities, located in Romania, at varying distances from the seismic hotspot situated in the Curvature Carpathians area, Vrancea County. Earthquakes with the epicenter in Vrancea Seismic Zone manifest themselves over large areas throughout Romania, at high intensities. These earthquakes are generated by the subduction phenomenon, as the Scythian Platform subducts under the Carpathian Orogen. In order to determine the structural response and the way how the buildings subjected to seismic action behave, a program for automated structural calculation was used. The study comprises the earthquake response simulation of a reinforced concrete frame building structure, placed in the two target settlements, with different ground acceleration values. The seismic simulations showcase the structure in 2 different vibration modes with displacements on each level. The results support informed design of civil, industrial and agricultural constructions and proper dimensioning of structural elements, according to the desired features. Dynamic actions generate forces of inertia that influence the expression of the dynamic equilibrium conditions in addition to the directly applied forces and reactions. It can be emphasized that the response of a structure to the dynamic actions depends on the actual loads, the resistance capacity, the size and the distribution of masses within the structure. [ABSTRACT FROM AUTHOR]

Modal analysis is an important step in optimal design of the spindle. Speedy cotton spindles of JW.D3203 are studied in this paper. The structural features of the spindle are described. ANSYS finite element analysis software is used for modeling of the spindle. Setting material properties, defining element type, meshing, and determining the boundary conditions are done before the top ten mode figures of spindle are gotton. The natural frequency and critical speed are gotton. Resonance phenomena is avoided when the speed of spindle reaches the critical speed. The simulation results have a good guide for structural optimization of the spindle. [ABSTRACT FROM PUBLISHER]

This paper investigates a relationship between vibration of an interior permanent magnet synchronous motor and an inverter PWM carrier signal by the analysis and the experimental results. A coupling analysis between a circuit simulator and an FEA is used to analyze the flux density which the carrier harmonics are included in the air gap. The vibration analysis is carried out by using the flux density in the air gap and the vibration around the carrier frequency can be analyzed. Adding that, the experiments which are both the tracking analysis and the mode analysis are carried out to confirm the analysis results. Furthermore, in order to reduce the vibration due to that the inverter PWM carrier signal a current hysteresis control is adopted instead of the PWM control. This verification shows the effectiveness of the proposed reduced vibration technique by both simulation and experimental results. [ABSTRACT FROM PUBLISHER]

In this paper, we present a type of vacuum/solid phononic crystal composed of two-dimensional Helmholtz resonators, which is called Helmholtz resonant phononic crystals. By using the finite element method, bandgaps and vibration modes are studied. The numerical computation is performed by Comsol Multiphysics 3.5a. The results show that complete resonant bandgaps exist for the Helmholtz resonant phononic crystals, and also a lower full bandgap appears for the mixed mode. The results are related to optimization of the acoustic bandgaps. [ABSTRACT FROM PUBLISHER]