Experimental Centrifuge Testing and Analytical Studies of Particle Damping Behavior

2000 ◽  
Author(s):  
Eric M. Flint ◽  
Eric Ruhl ◽  
Steven E. Olson
Keyword(s):  
Centrifuge Testing ◽  
Analytical Studies ◽  
Damping Behavior ◽  
Particle Damping

scholarly journals Damping prediction of particle dampers for structures under forced vibration using effective fields

2021 ◽  
Vol 23 (3) ◽  
Author(s):  
Niklas Meyer ◽  
Robert Seifried
Keyword(s):  
Energy Dissipation ◽  
Knowledge Exchange ◽  
Underlying Structure ◽  
Reduction Techniques ◽  
Linear Behavior ◽  
Damping Behavior ◽  
Effective Particle ◽  
Coupling Procedure ◽  
Particle Damping ◽  
Particle Dampers

AbstractParticle damping is a promising damping technique for a variety of technical applications. However, their non-linear behavior and multitude of influence parameters, hinder currently its wide practical use. So far, most researchers focus either on determining the energy dissipation inside the damper or on the overall damping behavior when coupled to a structure. Indeed, currently almost no knowledge exchange between both approaches occurs. Here, a bridge is build to combine both techniques for systems under forced vibrations by coupling the energy dissipation field and effective particle mass field of a particle damper with a reduced model of a vibrating structure. Thus, the overall damping of the structure is estimated very quickly. This combination of both techniques is essential for an overall efficient dimensioning process and also provides a deeper understanding of the dynamical processes. The accuracy of the proposed coupling method is demonstrated via a simple application example. Hereby, the energy dissipation and effective mass of the particle damper are analyzed for a large excitation range first using a shaker setup. The particle damper exhibits multiple areas of different efficiency. The underlying structure is modeled using FEM and modal reduction techniques. By coupling both parts it is shown that multiple eigenmodes of the structure are highly damped using the particle damper. The damping prediction using the developed coupling procedure is validated via experiments of the overall structure with particle damper.

EXPERIMENTAL AND ANALYTICAL STUDIES OF VERTICAL AXIS WIND TURBINES

2018 ◽  
pp. 51-58
Author(s):  
B. P. Khozyainov
Keyword(s):  
Wind Turbine ◽  
Flow Velocity ◽  
Wind Power ◽  
Wind Turbines ◽  
Power Efficiency ◽  
Air Flow ◽  
Geometrical Parameters ◽  
Wind Speeds ◽  
Analytical Studies ◽  
Air Flow Velocity

The article carries out the experimental and analytical studies of three-blade wind power installation and gives the technique for measurements of angular rate of wind turbine rotation depending on the wind speeds, the rotating moment and its power. We have made the comparison of the calculation results according to the formulas offered with the indicators of the wind turbine tests executed in natural conditions. The tests were carried out at wind speeds from 0.709 m/s to 6.427 m/s. The wind power efficiency (WPE) for ideal traditional installation is known to be 0.45. According to the analytical calculations, wind power efficiency of the wind turbine with 3-bladed and 6 wind guide screens at wind speedsfrom 0.709 to 6.427 is equal to 0.317, and in the range of speed from 0.709 to 4.5 m/s – 0.351, but the experimental coefficient is much higher. The analysis of WPE variations shows that the work with the wind guide screens at insignificant average air flow velocity during the set period of time appears to be more effective, than the work without them. If the air flow velocity increases, the wind power efficiency gradually decreases. Such a good fit between experimental data and analytical calculations is confirmed by comparison of F-test design criterion with its tabular values. In the design of wind turbines, it allows determining the wind turbine power, setting the geometrical parameters and mass of all details for their efficient performance.

Akomodasi Virus N Ach Terhadap Etos Kerja Islami Sebagai Motivasi Kerja

2018 ◽  
Vol 6 (2) ◽  
pp. 199-244
Author(s):  
Kholilur Rahman
Keyword(s):  
Transpersonal Psychology ◽  
Work Ethic ◽  
Work Motivation ◽  
Humanistic Psychology ◽  
Human Beings ◽  
Work Ethics ◽  
Analytical Studies ◽  
Islamic Work Ethic ◽  
High Work ◽  
Motivational Psychology

Human beings as psycho-physical who can produces work ethics that appears from inside of themselves soul, necessarily, the realm of analytical studies leads to motivational psychology. N Ach is one of the proper phenomena which is assumed to be something that can play an important role for the formation of superior human beings regarding to work. However, not all psychology scientists agree that work motivation comes from revelation or religion, therefore this study will clarify psychological studies which are considered to have proportional accommodative attitudes. Religion Psychology, Transpersonal Psychology and Humanistic Psychology are thought schools those have fair and objective attitudes and views on the Islamic teachings and Islamic dogma as a source of work motivation. People who have high N Ach and also the person who actualized it is a factors or elements that can emerge a high work ethic, then it shows that there is a potential high work ethic from muslim’s faith that was built on the basics of Al-Qur 'an and As-Sunnah. Faith without worship acts/work which was included abaout physical and psychological work, so also if the work ethic is not based on the concept of worship acts and fitht, it cannot be categorized as Islamic work. Then it was called the Islamic work ethic.

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