Analytical studies on the LAOS behaviors of some popularly used viscoelastic constitutive equations with a new insight on stress decomposition of normal stresses

2017 ◽  
Vol 29 (9) ◽  
pp. 093103 ◽  
Author(s):  
Jung-Eun Bae ◽  
Kwang Soo Cho
Author(s):  
B. P. Khozyainov

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.


2007 ◽  
Vol 35 (4) ◽  
pp. 276-299 ◽  
Author(s):  
J. C. Cho ◽  
B. C. Jung

Abstract Tread pattern wear is predicted by using an explicit finite element model (FEM) and compared with the indoor drum test results under a set of actual driving conditions. One pattern is used to determine the wear rate equation, which is composed of slip velocity and tangential stress under a single driving condition. Two other patterns with the same size (225/45ZR17) and profile are used to be simulated and compared with the indoor wear test results under the actual driving conditions. As a study on the rubber wear rate equation, trial wear rates are assumed by several constitutive equations and each trial wear rate is integrated along time to yield the total accumulated wear under a selected single cornering condition. The trial constitutive equations are defined by independently varying each exponent of slip velocity and tangential stress. The integrated results are compared with the indoor test results, and the best matching constitutive equation for wear is selected for the following wear simulation of two other patterns under actual driving conditions. Tens of thousands of driving conditions of a tire are categorized into a small number of simplified conditions by a suggested simplification procedure which considers the driving condition frequency and weighting function. Both of these simplified conditions and the original actual conditions are tested on the indoor drum test machines. The two results can be regarded to be in good agreement if the deviation that exists in the data is mainly due to the difference in the test velocity. Therefore, the simplification procedure is justified. By applying the selected wear rate equation and the simplified driving conditions to the explicit FEM simulation, the simulated wear results for the two patterns show good match with the actual indoor wear results.


2018 ◽  
Vol 6 (2) ◽  
pp. 199-244
Author(s):  
Kholilur Rahman

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.


1978 ◽  
Vol 18 (3) ◽  
pp. 85-95
Author(s):  
Hideo Sekiguchi

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