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Modeling of MEMS Resonator Piezoelectric Disc Partially Covered with Electrodes
Ismail Naciri,
Lahoucine Elmaimouni,
Jean-Etienne Lefebvre,
Faniry Emilson Ratolojanahary,
Mohamed Rguiti,
Tadeusz Gryba
Issue:
Volume 4, Issue 1, November 2016
Pages:
1-9
Received:
31 August 2016
Accepted:
26 September 2016
Published:
19 October 2016
Abstract: The Legendre polynomial method has been extended to the modeling of MEMS resonator disc partially covered with electrodes. The disc has been divided into two areas: one with electrodes and the other without electrodes. For each area, The Maxwell equations and the piezoelectric constitutive equations of motion are studied and solved to yield a frequency response and electrical behavior of the MEMS resonator applying a semi analytical method based on a Legendre polynomials series and trigonometric functions. However, the method allows incorporating the boundary conditions directly into the governing equations by assuming position-dependent of elastic constants, mass density and delta functions. The alternating electrical source is described by specific terms which are also introduced into the equation of motion. The formalism has been developed which allows for both harmonic and modal analyses. In order to validate our polynomial approach, numerical results are presented such as resonant and anti-resonant frequencies, electric input admittance, electromechanical coupling coefficient and field profiles of fully and partially metallized PZT5A resonator discs. The results obtained were compared with those obtained by an approximated analytical method. The developed software proves to be very efficient to retrieve the contour modes of all orders.
Abstract: The Legendre polynomial method has been extended to the modeling of MEMS resonator disc partially covered with electrodes. The disc has been divided into two areas: one with electrodes and the other without electrodes. For each area, The Maxwell equations and the piezoelectric constitutive equations of motion are studied and solved to yield a frequ...
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Automobile – A Means of Transportation Cause of Accidents on Nigerian Roads, Its Effect on Human Life
Ohwojero Chamberlain Joseph
Issue:
Volume 4, Issue 1, November 2016
Pages:
10-14
Received:
26 August 2016
Accepted:
5 October 2016
Published:
7 November 2016
Abstract: Accident on Nigerian roads has become a serious threat and concern to every road user. Many Nigerians lost their lives through auto-crash, over 60% of Nigerians that make use of automobile as a means of mobility dies or suffer from injuries every year. Hence, this research was carried out to check and help reduce the rate of road accident on Nigerian high ways. The researcher used three companies that make use of transportation as a means of conveying goods and people as passengers. The companies are Dangote Group of Company; G. Agofure Motors and Peace Mass Transit. Data were collected through direct interview method and were analyzed using percentage, to know the frequency of road accidents. The analyses were represented on pie charts. Findings were observed and discussed after the analysis. Recommendations were made based on the findings to help reduce road accident on Nigerian roads.
Abstract: Accident on Nigerian roads has become a serious threat and concern to every road user. Many Nigerians lost their lives through auto-crash, over 60% of Nigerians that make use of automobile as a means of mobility dies or suffer from injuries every year. Hence, this research was carried out to check and help reduce the rate of road accident on Nigeri...
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Design and Mechanical Model Analysis of Magnetorheological Fluid Damper
Wentao Liu,
Yiping Luo,
Bin Yang,
Wen Lu
Issue:
Volume 4, Issue 1, November 2016
Pages:
15-19
Received:
11 October 2016
Accepted:
21 October 2016
Published:
16 November 2016
Abstract: Compared with the general damper, the MR fluid damper has the advantages of adjustable damping, large damping force and intelligence. Magneto rheological fluid damper is a unique role in the study of vibration, shock absorption, and tactile feedback. When the semi-active vibration control of the structure is carried out by the MR damper, the more accurate mechanical model of the damper is one of the key factors to achieve the better control effect of the MR damper. In this paper, the mechanical model of several magneto rheological fluid dampers is analyzed, and the characteristics are analyzed, and the design of MR fluid damper is performed on the basis of the analysis results.
Abstract: Compared with the general damper, the MR fluid damper has the advantages of adjustable damping, large damping force and intelligence. Magneto rheological fluid damper is a unique role in the study of vibration, shock absorption, and tactile feedback. When the semi-active vibration control of the structure is carried out by the MR damper, the more a...
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Research on Friction Material with Carbon Fiber and Melamine Modified Phenolic Resin
Wang Chengmin,
Yang Xuefeng,
Cai Xiguang,
Li Yunxi,
Guan Yonghao,
Zhang Hui
Issue:
Volume 4, Issue 1, November 2016
Pages:
20-24
Received:
29 November 2016
Published:
1 December 2016
Abstract: A friction material was developed after studying carbon fiber and melamine modified phenolic resin, which was made by thermo-compression craft. Thermal stress coupled field of friction material is analyzed by ABAQUS finite element software, the physical mechanical and friction and wear performance were investigated, the worn surfaces wear mechanism of friction materials were observed by Scanning Electron Microscope (SEM)and x-ray diffractometer, and comparison with ordinary phenolic resin friction material. It is shown that the friction and wear performance can be improved for friction material using both carbon fiber and melamine modified phenolic resin at the condition of high temperature, and the thermal decomposition and thermal fading of friction material were reduced in braking process. The mechanical properties and friction and wear properties of friction materials of melamine modified resin are improved compared with the friction materials of phenolic resin brake pads. It is thermal abrasion at high temperature due to phenolic resin decomposition accompanying with abrasive wear and fatigue abrasion, the wear mechanism of friction materials of melamine modified phenolic resin brake pad is fatigue abrasion.
Abstract: A friction material was developed after studying carbon fiber and melamine modified phenolic resin, which was made by thermo-compression craft. Thermal stress coupled field of friction material is analyzed by ABAQUS finite element software, the physical mechanical and friction and wear performance were investigated, the worn surfaces wear mechanism...
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Research on Structure Design of Dynamic Hydrocyclone on Board Ship
Cheng Xiang-xin,
Zhang Qiang,
Wu Shuo,
Li De-yu
Issue:
Volume 4, Issue 1, November 2016
Pages:
25-29
Received:
24 October 2016
Accepted:
15 November 2016
Published:
14 December 2016
Abstract: Treatment about bilge water is always one key point of the ship pollution prevention, at present, separation accuracy of the separator on board can reach requirements of specification for sea-going ships pollution prevention, but the separation of quantity and convenience of operation aspects are still to be improved. The ship oily water dynamic hydrocyclone separator can both meet to the above two aspects. The thinking of structure design and the manufacturing and assembly are discussed. The main structure of ship oily water dynamic hydrocyclone separator and its working principle are introduced. The basic parameters of the device working conditions are provided. The new method onboard ship oily water treatment is put forward. It can be used as references for researchers on oily water disposal.
Abstract: Treatment about bilge water is always one key point of the ship pollution prevention, at present, separation accuracy of the separator on board can reach requirements of specification for sea-going ships pollution prevention, but the separation of quantity and convenience of operation aspects are still to be improved. The ship oily water dynamic hy...
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