The Babylonian Talmud (dated to 300 CE) lists seven laws which God gave to the Children of Noah (B’nei Noach): 1 Acknowledge that there is only one G-d who is Infinite and Supreme above all things. Do not replace that Supreme Being with finite idols,… Read more
Here are the materials for sine vibration: PowerPoint File: webinar_sine.ppt Channel beam accelerometer data: channel.txt time(sec) & accel(G) Papers: POGO Oscillation Smallwood Algorithm Matlab script Vibrationdata Signal Analysis Package * * * Here is the audio/visual file link: NESC Academy Sine Vibration – Recommend viewing in Firefox… Read more
The Book of Ruth begins with the story of Elimelech who married Naomi. They and their two sons, Mahlon and Chilion, moved from Bethlehem to Moab, because their was a famine in their homeland. The sons married Moabite women. One son married Orpah, and the… Read more
Here is a script for reading ASCII text files into Matlab: read_data.m This script uses uigetfile to open a dialog box for selecting the input file. – Tom Irvine
Here is a Matlab script that converts a time history to a format which can be input to Femap or some other preprocesser for Nastran analysis. time_history_nastran.m with supporting function: datafix.m It can be used for force, pressure, acceleration or other amplitude types. The script… Read more
We held our first Shock & Vibration Webinar on January 17, 2014. This presentation was sponsored by the NASA Engineering and Safety Center, to which I express gratitude. A link to the audio/visual recording will be posted here in the near future. In addition, here… Read more
The Rice characteristic frequency f of a time history is where y is the amplitude It is useful for estimating the dominant frequency for signal which is fairly sinusoidal. Here is a Matlab script: rice_frequency.m See also: Vibrationdata Signal Analysis Package – Tom Irvine
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
Here is a paper which gives a derivation of the mass and stiffness matrices for beam bending: beam_FEM.pdf * * * Here is a Matlab script for the modal analysis of a straight beam. beam.zip * * * Here is Matlab script for the modal… Read more
This post is a work-in-progress… Frequency Response Function based substructuring (FBS) predicts the dynamic behavior of a coupled system on the basis of free interface FRFs of the uncoupled components. Here is a tutorial paper: Frequency Response Function Substructuring Modal damping requires special consideration: Notes on… Read more