Recommended References

IEST-RD-DTE012: Handbook for Dynamic Data Acquisition and Analysis The purpose of this Handbook, IEST-RD-DTE012.2, is to provide guidelines for acquiring and analyzing structural (or mechanical) shock and vibration, and acoustic and aerodynamic noise data from flight and ground tests for all categories of aerospace vehicles. The guidelines may also be used for dynamic measurements on [...]

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NASA Lessons Learned

Dr. Curtis Larsen asked me to distribute this newly-published “Lessons Learned” document. It is oriented to systems engineering. NASA/CR—2011–216468, Lessons Learned in Engineering J.C. Blair, R.S. Ryan, and L.A. Schutzenhofer Al Signal Research, Inc., Huntsville, Alabama Download Link Topics of interest include: turbopump vibration & fatigue, pogo oscillations, SRB reentry acoustics & ignition overpressure

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Low Cycle Shock Fatigue

Some colleagues and I recently debated whether fatigue relationships could be applied to repetitive shock environments.  Each of us had a persuasive hypothesis as to whether fatigue was applicable, but none had any data to support his claim. I thus perform my own test at home using Sony transistor radios, as presented in: http://www.vibrationdata.com/low_cycle_fatigue.pdf Each [...]

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Python Wiki

With the encouragement of my NASA colleagues, I have started a Python Wiki at: http://vibrationdata.com/python-wiki/index.php?title=Main_Page Please visit this site and contribute your own experience. Thank you, Tom Irvine

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FreeMat Evaluation

FreeMat is an open-source software environment similar to Matlab. The latest version is 4.0, released 2009-10-09. I tried FreeMat with one of my Matlab scripts which prompts the user for keyboard input. Unfortunately, this resulted in an error: In /usr/local/share/FreeMat-4.0/toolbox/io/input.m(input) at line 37 In /home/jarle/freemat/inndata.m(inndata) at line 3 In docli(builtin) at line 2 In base(base) [...]

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Python: reading two columns of numerical data with an arbitrary number of header & blank lines

Here is my current method. Please let me know if you have a better one. The input data may be either space, tab, or comma delimited. ########################################################################## import os import re from numpy import array,zeros,concatenate,linspace,std from sys import stdin import matplotlib.pyplot as plt ######################################################################## def start(): print(” “) print(“Entpath =stdin.readline() file_path = input_file_path.rstrip(‘\n’) if os.path.exists(file_path): [...]

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