scholarly journals High-Fidelity, High-speed, 3-D Finite-Element Modeling of Acoustic Scattering From Objects in Shallow Water

2008 ◽  
Author(s):  
David S. Burnett
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Shallow Water ◽  
High Speed ◽  
Acoustic Scattering ◽  
High Fidelity ◽  
Element Modeling

Finite-Element Modeling of Acoustic Scattering from Objects in Shallow Water

2007 ◽  
Author(s):  
David S. Burnett ◽  
Kwang H. Lee ◽  
Gary S. Sammelmann
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Shallow Water ◽  
Acoustic Scattering ◽  
Element Modeling

Friction Induced Vibration in Windscreen Wiper Contacts

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Tom Reddyhoff ◽  
Oana Dobre ◽  
Julian Le Rouzic ◽  
Nicolaas-Alexander Gotzen ◽  
Hilde Parton ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
High Speed ◽  
Contact Angles ◽  
Element Modeling ◽  
Friction Measurements ◽  
Mixed Lubrication Regime ◽  
Bending Modes ◽  
Intermediate Surface ◽  
Friction Induced Vibration

This research is aimed at understanding the mechanisms that give rise to friction induced noise in automotive windscreen wipers, with a focus on frequencies between 500 and 3500 Hz. To study this phenomenon, experimental friction, sound, and high-speed video measurements are combined with finite element modeling of a rubber wiper/glass contact. In agreement with previous research, simultaneous sound and friction measurements showed that wiper noise in this frequency range results from the negative damping effect caused by the dependence of friction on speed in the mixed lubrication regime. Furthermore, during sliding, the friction induced noise recorded by the microphone occurred in one of two frequency ranges (close to 1000 Hz and between 2000 and 2500 Hz). These coincided closely with the eigen-frequencies of first two bending modes, predicted by finite element modeling. Experimental observations also showed the wiper to be oscillating backward and forward without any torsional motion and that the thickness of the glass had no effect on the emitted noise. These observations highlight how friction induced noise—although caused by conditions within contact—has characteristics that are determined by the structure of the excited component. A number of additional findings are made. Most importantly, both experiment and finite element modeling showed that the presence of water in contact with the wiper modulates the frequency and amplitude of the emitted noise by effectively adding mass to the vibrating system. While this is occurring, Faraday-like standing waves are observed in the water. In addition to this, friction induced vibration is shown only to occur for glass surfaces with intermediate surface energies, which is possibly due to high contact angles preventing water reaching the contact. Based on the understanding gained, a number of suggestions are made regarding means of reducing windscreen wiper noise.

scholarly journals Finite element modeling of high-speed milling 7050-T7451 alloys

2020 ◽  
Vol 43 ◽  
pp. 471-478
Author(s):  
Xianghui Huang ◽  
Jinyang Xu ◽  
Ming Chen ◽  
Fei Ren
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
High Speed ◽  
High Speed Milling ◽  
Element Modeling
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