Browsing by Author "Wang, Y. P."

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AGV-induced floor micro-vibration assessment in LCD factories by using a regressional modified Kanai-Tajimi moving force model
(2013-02-25)
Lee, C. L.
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Su, R. K. L.
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Wang, Y. P.
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土木工程學系
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Department of Civil Engineering
This study explores the floor micro-vibrations induced by the automated guided vehicles (AGVs) in liquid-crystal-display (LCD) factories. The relationships between moving loads and both the vehicle weights and speeds were constructed by a modified Kanai-Tajimi (MKT) power spectral density (PSD) function whose best-fitting parameters were obtained through a regression analysis by using experimental acceleration responses of a small-scale three-span continuous beam model obtained in the laboratory. The AGV induced floor micro-vibrations under various AGV weights and speeds were then assessed by the proposed regressional MKT model. Simulation results indicate that the maximum floor micro-vibrations of the target LCD factory fall within the VC-B and VC-C levels when AGV moves at a lower speed of 1.0 m/s, while they may exceed the acceptable VC-B level when AGV moves at a higher speed of 1.5 m/s. The simulated floor micro-vibration levels are comparable to those of typical LCD factories induced by AGVs moving normally at a speed between 1.0 m/s and 2.0 m/s. Therefore, the numerical algorithm that integrates a simplified sub-structural multi-span continuous beam model and a proposed regressional MKT moving force model can provide a satisfactory prediction of AGV-induced floor micro-vibrations in LCD factories, if proper parameters of the MKT moving force model are adopted.
An analytical and experimental study of TLCD for structural vibration control
(2005)
Wang, Y. P.
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Lee, C. L.
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Hwu, T. H.
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Chen, L.
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土木工程學系
Tuned Liquid Column Damper (TLCD), an integration of vibration control damper with the fire protection hydraulic tank, is considered to be a substitute of the conventional tuned mass dampers (TMD) for vibration control of high-rise buildings. It possesses advantageous features as being easy-tuning, dual-function, maintenance-free and cost-effective. The TLCD system is, in most literature, analyzed as a linear dynamic system by introducing an equivalent viscous damping coefficient related to a constant headloss coefficient and a certain steady-state sloshing amplitude. In this study, the dynamic characteristics of TLCD systems with various orifice sizes have been investigated via component tests using harmonic excitations at various driving frequencies. The headloss coefficients have also been identified with a proposed system identification procedure based on ARX model. It is found that the smaller the opening size, the larger the headloss coefficient; and, the stronger the disturbing amplitude, the smaller the headloss coefficient. In addition, a series of shaking table tests of an aluminum modal frame with and without TLCD has been conducted to verify the effectiveness of adopting TLCD system for structural control. Numerical predictions of the liquid sloshing displacement and structural responses by the proposed analytical model with the experimentally identified headloss coefficient agree very well with the test data, verifying adequacy of the proposed analytical model. Further parametric analysis indicates that the longer the horizontal part the more pronounced the controlling effect. Moreover, if the horizontal portion is restrained due to practical considerations, increasing the tube diameter of the vertical segment may further improve the controlling effect. Finally, the numerical simulation of structural vibration control using TLCD system for Taipei 101 building has also illustrated in this paper.
Design and simulation of a MEMS high G inertial impact sensor
(2008)
Wang, Y. P.
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Hsu, R. Q.
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Wu, C. W.
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機械工程學系
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Department of Mechanical Engineering
Conventional inertial impact sensors typically use mechanisms such as cantilever beams or axial springs as triggering devices. Reaction time for these conventional impact sensors are either far too slow or, in many cases, fail to function completely for high G applications. In this study, a MEMS high G inertial impact sensor with a measurement range of 8,000-21,000 G is presented. The triggering mechanism is a combination of cantilever and spring structure. The design of the mechanism underwent a series of analyses. Simulation results indicated that a MEMS high G inertial impact sensor has a faster reaction time than conventional G inertial impact sensors that use a cantilever beam or spring mechanism. Furthermore, the MEMS high G inertial impact sensor is sufficiently robust to survive the impact encountered in high G application where most conventional G inertial impact sensors fail.
Design and Test of a MEMS-Based High G Smart Sensor
(2011-04-01)
Wang, Y. P.
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Hsu, R. Q.
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Wu, C. W.
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機械工程學系
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Department of Mechanical Engineering
Most conventional G sensors use cantilever beams or axial springs as triggering devices. The reaction time of these conventional G sensors are often far too long. In many high G (> 300 G) applications, they completely fail to function. This study proposed a microelectromechanical systems-based high G smart sensor, which not only functions at a very high G impact but also identifies the material when a projectile makes an impact on a hard object. This high G smart sensor is intended for use at 3000-21 000 G. The sensor was made of silicon and the triggering mechanism involves a cantilever and a spring structure. The mechanical sensitivity of the sensors can be adjusted to preset the triggering G value. Four sensors, each designated to trigger its own G value were integrated in a unit. Experiments demonstrated that this unit can identify the characteristics of an object.
DESIGN OF A NON-POWERED MEMS HIGH G SHOCK SENSOR
(2008)
Wang, Y. P.
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Hsu, R. Q.
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Wul, C. W.
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機械工程學系
;
Department of Mechanical Engineering
Conventional shock sensors typically use mechanisms such as cantilever beams or axial springs as triggering devices. Reaction time for these conventional shock sensors are either far too slow or, in many cases, fail to function completely for high G (> 300G) applications. In this study, a non-powered MEMS high G shock sensor with a measurement range of 3,000-21,000 G is presented. The triggering mechanism is a combination of cantilever and spring structure. The design of the mechanism underwent a series of analyses. Simulation and test results indicated that a MEMS high G shock sensor has a faster reaction time than conventional G shock sensors that use a cantilever beam or spring mechanism. Furthermore, the MEMS high G shock sensor is sufficiently robust to survive the impact encountered in high G application where most conventional G shock sensors fail.
Finite Element Analysis of a MEMS-Based High G Inertial Shock Sensor
(2008)
Wang, Y. P.
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Hsu, R. Q.
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Wu, C. W.
;
機械工程學系
;
Department of Mechanical Engineering
Conventional mechanical inertial shock sensors typically use mechanisms such as cantilever beams or axial springs as triggering devices. Reaction time for these conventional shock sensors are either far too slow or, in many cases, fail to function completely for high G (> 300G) applications. In this study, a Micro-Electro-Mechanical (MEMS)-based high G inertial shock sensor with a measurement range of 3,000-21,000 G is presented. The triggering mechanism is a combination of cantilever and spring structure. The design of the mechanism underwent a series of analyses. Simulation results indicated that a MEMS-based high G inertial shock sensor has a faster reaction time than conventional G inertial shock sensors that use a cantilever beam or spring mechanism. Furthermore, the MEMS-based high G inertial shock sensor is sufficiently robust to survive the impact encountered in high G application where most conventional G inertial shock sensors fail.
Seismic spectral acceleration assessment of masonry in-filled reinforced concrete buildings by a coefficient-based method
(2012-02-25)
Su, R. K. L.
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Lee, C. L.
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Wang, Y. P.
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土木工程學系
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Department of Civil Engineering
This study explores a coefficient-based seismic capacity assessment method with a special emphasis on low-rise masonry in-filled (MI) reinforced concrete (RC) buildings subjected to earthquake motion. The coefficient-based method without requiring any complicated finite element analysis is a simplified procedure to assess the maximum spectral acceleration capacity of buildings. This paper first compares the fundamental periods of MI RC structures obtained, respectively, from experimental period data and empirical period-height formulas. The coefficient-based method for low-rise masonry buildings is then calibrated by the published experimental results obtained from shaking table tests. The comparison of the experimental and estimated results indicates that the simplified coefficient-based method can provide good approximations of the maximum spectral accelerations at peak loads of the low-rise masonry reinforced concrete buildings if a proper set of drift factors and initial fundamental vibration periods of structures are used.