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
Modal Transient Analysis of a Multi-degree-of-freedom System with Enforced Motion: modal_enforced_motion.pdf Matlab scripts: enforced_displacement.zip enforced_acceleration.zip * * * Frequency Response Function Analysis of a Multi-degree-of-freedom System with Enforced Motion: FRF_enforced_motion.pdf Matlab scripts: enforced_acceleration_frf.zip enforced_displacement_frf.zip * * * Multi-Degree-of-Freedom System Response to Multipoint Base Excitation Modal… Read more
Consider a single-degree-of-freedom system subject to base excitation. Assume a case where the base input is a sine tone which must be converted to an “equivalent” narrowband PSD. The narrowband PSD must be greater than or equal to the sine tone in terms of peak… Read more
Here is a Matlab GUI script to calculate displacement, velocity, and acceleration at a given frequency for a steady-state sine function. sine_amplitude.zip This module is also included in: Vibrationdata Matlab Signal Analysis Package – Tom Irvine
Engineers prepare the MESSENGER spacecraft for a vibration test at The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., where the Mercury-bound NASA spacecraft was designed and built. * * * Introduction Flight configured spacecraft are subjected to base input vibration tests for certain programs.… Read more
N571UP, the aircraft involved, seen taking off from Dubai in November 2008 * * * A UPS Boeing 747-400 flying between Dubai International Airport and Cologne Bonn Airport crashed close to Dubai airport, killing the two crew members, on September 3, 2010. The aircraft had… Read more
I may have an upcoming opportunity to perform signal processing on some satellite data for tracking storms and ocean wave heights… Anyway, I am studying some radar books in preparation. * * * Here are some Matlab scripts for monostatic pulsed radar systems: target_range.zip -… Read more
Matlab GUIDE is a package for generating graphical user interface (GUI) scripts. Extracting Numerical Data from a Matlab uitable The table format was set to text using the Table Property Editor. The number of rows is equal to N. There are three columns of data: peak,… Read more
Matlab has very good plotting capabilities, but the required command syntax is somewhat awkward. Here is a hopefully user-friendly GUI for plotting XY curves from array data. The data must have two columns. Typical applications would be for a time history or frequency response function.… Read more
