Low Frequency Sound Transmission into Offshore Cabin
The strongest helicopter noise is found at frequencies below 100 Hz. Helicopter landing and take off at platforms can cause sleep disturbances. Offshore space is premium. Cabins therefore tend to be compact. Cabins are also module-built and installed side-by-side, which leads to complicated acoustic interrelation regarding flanking transmission paths. To further compound the issue, a platform is very stiff compared to an ordinary building on land. Many of the truths known in building acoustics, therefore, do not hold. At low frequency, stiffness is the governing factor for sound transmission...
read moreFinite Element Analysis of Sound Transmission Through Pipes
Qring uses Code Aster (CA) as its FE code (Link). The development version of CA is freeware. CA is a very competent FE code for the analysis of vibration, stress, fatigue, acoustics and pulsation. Below is a small example of sound transmission through pipe sections. The analysis results from these generic models were used to support analysis and decision-making for acoustics at plant level. This example is of interest as a way to use Finite Element Analysis, which can be used only for limited segments of a system, to assess data for several kilometers of piping. The analysis is made as...
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