• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.1120-1125
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• 2001

A new concept of piezoelectric smart panels for noise reduction in wide band frequencies is proposed and their possibility is experimentally investigated. Multi-mode damping is studied by using a newly proposed tuning method. The proposed panels are based on passive shunt damping methods. This method is based on electrical impedance model and maximizing the dissipated energy at the shunt circuit. four PZT are attached on smart panel for improving performance of transmission noise reduction. 0 prove the concept of piezoelectric smart panels, an acoustic measurement experiment was performed. The smart panels exhibit a good noise reduction in middle and high frequency ranges due to the mass effects of absorbing materials or/and the air gap. The use of piezoelectric smart panel renders noise reduction at resonance frequency. Noise reduction at multiple resonance frequencies is experimentally investigaed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1273-1279
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• 2000

A new concept of piezoelectric smart panels for noise reduction in wide band frequencies is proposed and their possibility is experimentally investigated. The proposed panels are based on active and passive methods. They use piezoelectric smart structure technology for active noise reduction at low band frequencies and passive sound absorbing materials for mid-range of noise frequencies. To prove the concept of piezoelectric smart panels, an acoustic measurement experiment was performed. The smart panels exhibit a good noise reduction in middle and high frequency ranges due to the mass effects of absorbing materials or/and the air gap. The use of piezoelectric smart panel renders noise reduction large at resonance frequency. Another concept of smart panel that uses piezoelectric damping is experimentally investigated. Since piezoelectric dampings can reduce vibration and noise at resonance frequencies with simple shunt circuit, they have merits in terms of economy and simplicity. Dissipated energy method(DEM) is adopted to tune the shunt circuit precisely in piezoelectric dampings. Noise reduction at multiple resonance frequencies is demonstrated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.73-79
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• 2001

In this paper, the transmitted noise reduction performance of piezoelectric smart panels is experimentally studied. The proposed piezoelectric smart panels are comprised of plate structure on which piezoelectric sensor/actuators are bonded and sound absorbing material is provided. It is a combination of passive and active approaches utilizing a passive effect at high frequencies and an active effect at low frequencies. To prove the concept of piezoelectric smart panels, an acoustic measurement experiment is performed. An acoustic tunnel is designed and its acoustic characteristics are tested. Below 800Hz, the tunnel exhibits a plane wave guide characteristics. When an absorbing material is bonded on a single plate, a remarkable transmitted noise reduction in mid frequency range is observed except the first resonance frequency. By enabling the active control of single smart panel with negative feedback control. about 10dB noise reduction is achieved at the resonance frequencies. The double smart panel got 4dB at the first resonance frequency and has more potential to reduce the transmitted noise in a wide range frequency. Piezoelectric smart panels incorporating passive absorbing material and active piezoelectric devices is a promising technology for noise reduction in a wide range frequency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.327.2-327
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• 2002

In this paper, the transmitted noise reduction of smart panels of which passive piezoelectric shunt damping is used, is experimentally studied. Shunt damping experiments are based on the measured electrical impedance model. A passive shunt circuit composed of inductor, and load resistor is devised to dissipate the maximum energy into the joule heat energy For multi mode shunt damping, the shunt circuit is redesigned by adding a blocking circuit. (omitted)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.4
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• pp.300-307
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• 2003

This paper presents the multi-mode noise reduction of smart panels of which passive piezoelectric shunt damping is introduced. For the piezoelectric shunt damping, a passive shunt circuit composed of inductors and a load resistor is connected to the piezoelectric patch mounted on the panel structure. An electrical impedance model is introduced for the system based on the measured electrical impedance, and the criteria for maximum energy dissipation at the shunt circuit is used to find the optimal shunt parameters. For multi-mode shunt damping, the shunt circuit is modified by the introduction of a block circuit. Also the optimal location of the piezoelectric patch is studied by finite element analysis in order to cause the maximum admittance from the patch for each mode of the structure. An acoustic test is performed for the panels and a remarkable noise reduction is obtained in multiple modes of the panel structure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.216-221
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• 2002

In this paper, the transmitted noise reduction of smart panels of which passive piezoelectric shunt damping is used, is experimentally studied. Shunt damping experiments are based on the measured electrical impedance model. A passive shunt circuit composed of inductors, and a load resistor is devised to dissipate the maximum energy into the joule heat energy. For multi-mode shunt damping, the shunt circuit is redesigned by adding a blocking circuit. Also the optimal location of the piezoelectric patch is studied by FEM in order to cause the maximum admittance from the patch for each mode of aluminum plate. In results, the transmitted sound pressure level of panels is efficiently reduced for multi-modes

• Smart Structures and Systems
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• v.20 no.5
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• pp.637-640
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• 2017

The adoption of cladding panels as dissipation device is a sort of passive control "ante litteram" for residential and commercial buildings. This paper gives details on the current technology outlining the difference between buffer panels and cladding panels. The discussion of robustness and resilience of the resulting system is afforded. It is shown that the strength of such solution, originally related to economy and light weight, is mainly associated with the respect of the main robustness requisites, as well as the short time it requires for removal and replacement (resilience).

• International conference on construction engineering and project management
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• 2024.07a
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• pp.487-493
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• 2024

Presently, prefabricated concrete panels are extensively employed in diverse construction projects across the globe due to their exceptional quality. To maintain the overall quality of these construction projects, it is crucial to ensure that the dimensions of precast concrete panels align with their designated design specifications. Therefore, it is essential to develop a methodology capable of quickly and accurately measuring the dimensions of precast concrete panels. Currently, there are many advanced technologies used to examine the dimensions of prefabricated concrete panels such as terrestrial laser scanning, which is prone to time consuming and cost inefficiencies. To address these limitations, this study suggests a computer vision-based approach that utilizes April Tag markers and images taken from a mobile phone to measure and evaluate the dimensions and quality of precast concrete panels. The proposed algorithm operates as follows: Initially, the RGB image coordinates are converted to the world coordinate systems using April tag markers. Following, the masks of the precast concrete components are extracted using the state-of-the-art Segment Anything Model (SAM). Finally, an algorithm based on image processing technique is developed to estimate the dimensional properties of precast concrete panels. The effectiveness of the proposed method is validated through preliminary experiments conducted in the field-scale precast slabs, and the result is evaluated by comparing to the manual measurement result.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.1
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• pp.49-57
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• 2002

The possibility of a transmission noise reduction of piezoelectric smart panels using piezoelectric shunt damping is experimentally studied. Piezoelectric smart panel is basically a plate structure on which piezoelectric patch with shunt circuits is mounted and sound absorbing materials are bonded on the surface of the structure. Sound absorbing materials can absorb the sound transmitted at mid frequency region effectively while the use of piezoelectric shunt damping can reduce the transmission at resonance frequencies of the panel structure. To be able to reduce the sound transmission at low panel resonances, piezoelectric damping using the measured electrical impedance model is adopted. Resonant shunt circuit for piezoelectric shunt damping is composed of register and inductor in series, and they are determined by maximizing the dissipated energy throughout the circuit. The transmitted noise reduction performance of smart panels is investigated using an acoustic tunnel. The tunnel is a tube with square crosses section and a loud-speaker is mounted at one side of the tube as a sound source. Panels are mounted in the middle of the tunnel and the transmitted sound pressure across panels is measured. Noise reduction performance of a smart panels possessing absorbing material and/or air gap shows a good result at mid frequency region but little effect in the resonance frequency. By enabling the piezoelectric shunt damping, noise reduction of 10dB, 8dB is achieved at the resonance frequencise as well. Piezoelectric smart panels incorporating passive method and piezoelectric shunt damping are a promising technology for noise reduction in a broadband frequency.

• Steel and Composite Structures
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• v.14 no.6
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• pp.587-604
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• 2013

There are few technical documents regulated structural performance and engineering criteria in domestic market for Structural insulated panels in Korea. This paper was focused to identify fundamental performance under monotonic loading and cyclic loading for SIPs in shear wall application. Load-displacement responses of total twelve test specimens were recorded based on shear stiffness, strength, ultimate load and displacement. Finally energy dissipation of each specimen was analyzed respectively. Monotonic test results showed that ultimate load was 44.3 kN, allowable shear load was 6.1 kN/m, shear stiffness was 1.2 MN/m, and ductility ratio was 3.6. Cyclic test was conducted by two kinds of specimens: single panel and double panels. Cyclic loading results, which were equivalent to monotonic loading results, showed that ultimate load was 45.4 kN, allowable shear load was 6.3 kN/m. Furthermore the accumulated energy dissipation capability for double panels was as 2.3 times as that for single panel. Based on results of structural performance test, it was recommended that the allowable shear load for panels should be 6.1 kN/m at least.