Formulas for calculating the speed of sound in gases, liquids, and solids is given in: speed.pdf A Matlab function for these calculations is included in the package given at: Vibrationdata Matlab Signal Analysis Package The speed of sound calculator can be accessed within this package… Read more
Here is a chart showing the natural frequencies of piano keys: piano.pdf Here is a paper on some basic music theory: music.pdf * * * See also: Fun with Sound Files Wind Chime Acoustics Tuning Fork Sound and Vibration: tuning.pdf * * * – Tom… Read more
This set of scripts calculates the response of an SDOF system to an applied force PSD. A transfer function is derived. Then its square is applied to the force PSD to calculate the response, using point-by-point multiplication and integration. sdof_ran_force.zip Important note: The following scripts… Read more
There is a need to derive a PSD envelope for nonstationary acceleration time histories, including launch vehicle data, which may be similar to that shown in the above figure. A PSD can be derived using rainflow fatigue cycle counting along with a Miners-type relative fatigue… Read more
A colleague recently wrote to me regarding the merits of using statistical energy analysis to predict the vibration levels in a NASA launch vehicle. Here is my reply: I use “old-school” empirical scaling techniques. These work reasonably well for deriving component-level maximum predicted environments. I… Read more
Alas, the water drainage pipes in my home have developed a singing sound with a frequency of 400 Hz. This is slightly above a G note on the musical scale. The singing occurs when someone has finished taking a shower on the second floor. Here… Read more
Here is a Matlab script for Doppler shift calculations: doppler.mHere is a related Newsletter article and sound files: June2003_NL.pdfK5LA.wavcno_wav* * *See also: Vibrationdata Acoustics Page* * *- Tom Irvine
Here is a unit conversion calculator, written in Microsoft Visual C/C++. units.exe Do a right mouse click to download and save. It may appear in your system tray after you download and run it. The contents in the Results box can be copied and pasted… Read more
Making sound recordings is easy these days given that iPods, iPads and Android cell phones have this capability. Here is a freeware program that can be used to process the sound data: Audacity This program can also convert the sound file from one format to… Read more
