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
Howard A. Gaberson (1931-2013) was a shock and vibration specialist with more than 45 years of dynamics experience. He was with the U.S. Navy Civil Engineering Laboratory and later the Facilities Engineering Service Center from 1968 to 2000, mostly conducting dynamics research. Gaberson specialized in… Read more
Some power spectral density test specifications are too high in amplitude for a given shaker system. Bandsplitting can be cautiously used in these cases. Here is a brief guideline paper: bandsplit.pdf Here is a Matlab script that implements bandsplitting per the guidelines: bandsplit.zip The main script… 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
The Vibrationdata Signal Analysis Package has a function for calculating the natural frequencies of a plate simply-supported about all edges. The package also has options for calculating the response to base excitation. Vibrationdata > Structural Dynamics > Plates, Rectangular & Circular > Rectangular Plate, Simply Supported The… Read more
I am going to present: Extending Steinberg’s Fatigue Analysis of Electronics Equipment to a Full Relative Displacement vs. Cycles Curve at the Dynamic Environments Workshop in El Segundo, California, June 4-6, 2013. I know that travel budgets are very tight, but I hope to meet… Read more
MIL-STD-180G, Table 514.6C-X, Vibration induced by the main rotor and blade passing frequencies… Here is a script for calculating the sinusoidal frequencies and amplitudes: helicopter.m – Tom Irvine
Nehemiah was a Jew during the period where most Jews were in exile in Babylon. He served as a cup-bearer to Artaxeres, king of Persia and ruler over Babylon, around the time 445 BC. His duty was to taste the king’s drink to verify that… Read more
Here is Matlab script for plotting the MIL-STD-810G, Figure 514.6D-2, Category 13, Propeller Aircraft Vibration Exposure PSD, including the overall GRMS level. propeller_psd_grms.m * * * See also: Bombardier Q-400 Turboprop Acoustics Aircraft Shock & Vibration – Tom Irvine
Shock and vibration environments produce dynamic stresses which can cause material failure in structures. The potential failure modes include fatigue, yielding, and ultimate stress limit. F.V. Hunt wrote a seminal paper on this subject, titled “Stress and Stress Limits on the Attainable Velocity in Mechanical… Read more