Advances in impact noise insulation testing

2021 ◽  
Vol 150 (4) ◽  
pp. A118-A119
Author(s):  
Wayland Dong ◽  
John Lo Verde ◽  
Samantha Rawlings
Keyword(s):  
Impact Noise

Validity-Study of Commercial Semiconductor with TO-18 Package for Space Application by PIND Test

2013 ◽  
Author(s):  
Yusuke Nakatake ◽  
Makoto Okabe ◽  
Shota Sato
Keyword(s):  
Industrial Applications ◽  
Validity Study ◽  
Space Application ◽  
Noise Detection ◽  
Foreign Material ◽  
Contamination Control ◽  
X Ray ◽  
Impact Noise ◽  
Report Analysis ◽  
Foreign Materials

Abstract In this paper, we carried out PIND (Particle Impact Noise Detection) test and X-ray inspection of a transistor in a TO-18 package for commercial and industrial applications. From our evaluation results, we explain the validity of the PIND test by comparing PIND test and X-ray inspection results. We make clear that PIND test is able to detect internal foreign material that may be transparent to X-ray inspection. In addition, we report analysis results of internal foreign materials from defective devices. This matter suggests that a problem is contamination control in the manufacturing process, most likely the sealing process.

scholarly journals Study on Influence of Diameter on Detonation Acoustic Characteristics of Pulse Detonation Engine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Gui-yang Xu ◽  
Chun-guang Wang ◽  
Yan-fang Zhu ◽  
Hong-yan Li ◽  
Lun-kun Gong ◽  
...  
Keyword(s):  
Acoustic Characteristic ◽  
Pulse Detonation Engine ◽  
Acoustic Characteristics ◽  
Experiment System ◽  
Pulse Detonation ◽  
Impact Noise ◽  
Maximum Duration ◽  
Detonation Engine ◽  
Set Up ◽  
Different Diameters

AbstractThe experiment system of pulse detonation engine is set up to investigate on influence of diameter on detonation acoustic characteristic. The research of detonation acoustic characteristic of pulse detonation engine for four different diameters in different angles is carried out. Results from the test show that as the PDE diameter increasing, there are increases in amplitudes of impact noise in all angles, and the growth rate of amplitude of impact noise in the 90° direction is generally greater than that in the 0° direction. The smaller PDE diameter is, the distance of most obvious directivity at 0° turning to most obvious directivity at 30° is shorter. When the distance is shorter, such as 200 mm, the duration of detonation acoustic is increasing with the increase of PDE diameter, however, when the distance is longer, such as 3000 mm, it is just the opposite. The maximum duration of detonation acoustic is appeared in 3000 mm under 30 mm PDE diameter which reaches to 1.44 ms.

On the prediction of impact noise, I: Acceleration noise

1979 ◽  
Vol 62 (4) ◽  
pp. 547-575 ◽  
Author(s):  
E.J. Richards ◽  
M.E. Westcott ◽  
R.K. Jeyapalan
Keyword(s):  
Impact Noise

Using Wavelet Analysis to Distinguish Cavitation Acoustic Emissions From Blunt Impact Noise

2021 ◽  
Author(s):  
Christopher Eckersley ◽  
Joost Op 't Eynde ◽  
Mitchell Abrams ◽  
Cameron R. Bass
Keyword(s):  
Wavelet Transform ◽  
High Speed ◽  
Acoustic Noise ◽  
Bubble Formation ◽  
Acoustic Emissions ◽  
Wide Band ◽  
Water Tank ◽  
Impact Noise ◽  
Blunt Impact

Abstract Cavitation has been shown to have implications for head injury, but currently there is no solution for detecting the formation of cavitation through the skull during blunt impact. The goal of this communication is to confirm the wideband acoustic wavelet signature of cavitation collapse, and determine that this signature can be differentiated from the noise of a blunt impact. A controlled, laser induced cavitation study was conducted in an isolated water tank to confirm the wide band acoustic signature of cavitation collapse in the absence of a blunt impact. A clear acrylic surrogate head was impacted to induce blunt impact cavitation. The bubble formation was imaged using a high speed camera, and the collapse was synched up with the wavelet transform of the acoustic emission. Wideband acoustic response is seen in wavelet transform of positive laser induced cavitation tests, but absent in laser induced negative controls. Clear acrylic surrogate tests showed the wideband acoustic wavelet signature of collapse can be differentiated from acoustic noise generated by a blunt impact. Broadband acoustic signal can be used as a biomarker to detect the incidence of cavitation through the skull as it consists of frequencies that are low enough to potentially pass through the skull but high enough to differentiate from blunt impact noise. This lays the foundation for a vital tool to conduct CSF cavitation research in-vivo.

Effect of different types of ceilings on floor impact sound insulation performance in CLT model building

2021 ◽  
Vol 263 (2) ◽  
pp. 4402-4409
Author(s):  
Atsuo Hiramitsu ◽  
Susumu Hirakawa ◽  
Takahiro Tsuchimoto ◽  
Takashi Yamauchi
Keyword(s):  
Model Building ◽  
Sound Insulation ◽  
Impact Noise ◽  
Timber Construction ◽  
Stress Relieving ◽  
Measurement Results ◽  
Absorbing Material ◽  
Vibration Insulator ◽  
Effective Use ◽  
Insulation Performance

The floor impact noise generated in a building often causes problems among residents. The floor impact sound insulation performance of timber construction buildings is lower than that of concrete construction. However, due to the large supply of wood and the stress-relieving effects of wood, the use of wood is being promoted around the world. In Japan, the Act on the Promotion of the Utilization of Wood in Public Buildings was enforced to promote the use of CLT (Cross Laminated Timber) for the effective use of wood. We have been experimentally investigating the effect of floor finish structure in CLT model building. In this paper, we report the measurement results of the change in floor impact sound insulation performance when the suspended ceiling structure was changed. As results, it was confirmed that the effect of the sound-absorbing material in the ceiling cavity and the effect of the double-layer ceiling board were effective. In addition, it was clarified that the dry-type double floor structure with rubber vibration insulator on its legs is an effective floor finish structure for improvement of heavy and light weight floor impact sound insulation performances.

Theoretical and numerical investigation on impact noise radiated by collision of two cylinders

2014 ◽  
Vol 28 (6) ◽  
pp. 2017-2024 ◽  
Author(s):  
Yinggang Li ◽  
Tianning Chen ◽  
Xiaopeng Wang ◽  
Kunpeng Yu ◽  
Chao Zhang
Keyword(s):  
Numerical Investigation ◽  
Impact Noise

scholarly journals An Integrated Denoising Method for Sensor Mixed Noises Based on Wavelet Packet Transform and Energy-Correlation Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Chao Tan ◽  
Yanping Wang ◽  
Xin Zhou ◽  
Zhongbin Wang ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Wavelet Packet ◽  
Wavelet Packet Transform ◽  
Processing Method ◽  
Signal Denoising ◽  
Current Signal ◽  
Energy Correlation ◽  
Denoising Method ◽  
Impact Noise ◽  
Key Technologies

In order to solve the problem of industrial sensor signal denoising, an integrated denoising method for sensor mixed noises based on wavelet packet transform and energy-correlation analysis is proposed. The architecture of proposed method is designed and the key technologies, such as wavelet packet transformation, energy-correlation analysis, and processing method of wavelet packet coefficients based on energy-correlation analysis, are presented. Finally, a simulation example for a specific signal and an application of shearer cutting current signal, which mainly contain white Gaussian noise and impact noise, are carried out, and the simulation and application results show that the proposed method is effective and is outperforming others.

scholarly journals Experimental measurement and evaluation of the noise generated by three transmissions by synchronous belts of type AT10, BAT10 and SFAT10

2020 ◽  
Author(s):  
Merghache Sidi Mohammed ◽  
Hamdi Amine ◽  
Fernini Brahim
Keyword(s):  
Experimental Study ◽  
Angular Speed ◽  
Direct Transmission ◽  
Engine Torque ◽  
Linear Speed ◽  
Belt Drives ◽  
Impact Noise ◽  
Low Weight ◽  
Measurement And Evaluation ◽  
The Impact

Abstract Synchronous belt drives combine the advantages of simple belt drives (flat, trapezoidal or ridged) due to their low weight, low maintenance, large linear speed ranges and high transmission ratios with the advantages of chains: absence sliding, synchronized transmission of speed, low tensioning, etc. Thanks to the toothing of the belt which enters the corresponding one of the synchronous pulleys, there is direct transmission of the power without sliding as between two gears. This article develops an experimental study which makes it possible to see the influence of the angular speed, the engine torque and the setting tension on the impact noise of the belt teeth on the pulley teeth during meshing and vibrations of the free strands of the belt. We have measured the noise generated by three transmissions by synchronous belts of type AT10, BAT10 and SFAT10.

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