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
Amazon Product Link: Bose QuietComfort 3 Acoustic Noise Cancelling Headphones * * * * * * * * * * * * * * I have take several business trips lately with more to come. One of my pet peeves is hotel room noise from HVAC… Read more
This video shows the vibration of consoles in the Mobile Launch Platform underneath the Space Shuttle for the liftoff event. MLP Field Verification Video This video shows the “tennis shoe” method for exciting a rocket vehicle. Saturn V Apollo SA-500F Shake Test at VAB 1966… Read more
SCUD-B Typical Avionics Component The avionics shelves were made from hardwood. The wooden fibers may provide better damping then, say, an aluminum shelf. A possible disadvantage of wood is that the shelf would be unable to serve as an electrical or thermal ground plane. The… Read more
The Nyquist frequency is equal to one-half the sampling rate. Shannon’s sampling theorem states that a sampled time signal must not contain components at frequencies above the Nyquist frequency. Otherwise, an aliasing error will occur. * * * Here are some papers: Notes on sample… Read more