An important parameter in random vibration analysis is the peak response, which can be the maximum relative displacement, velocity, acceleration, stress or strain. The peak response can then be compared with the threshold for yielding, ultimate failure, etc. The peak is also important for fatigue… Read more
LV/SC Clampband Release Test Here is an excellent reference on shock testing and analysis: European Cooperation for Space Standardization, Space engineering, Mechanical Shock Design and Verification Handbook, ECSS-E-HB-32-25A, 14 July 2015 download link The Shock Handbook was covered in several presentations at the ESA 2nd Workshop on Spacecraft… Read more
I made a recording of a bird in my backyard in Madison, Alabama. The bird was up in a tall pine tree, and I could not see it. But I was able to identify it from its song with the help of someone on the… Read more
Rocket vehicles mounted on launch stands at Vandenberg AFB, California must be designed and analyzed to withstand potential earthquakes originating on the nearby San Andreas Fault. The vehicles behave as long, slender cantilever beams prior to liftoff. * * * I am going to present… Read more
Howdy! If you are interested in vibration fatigue please send me a reply. Email: tom@irvinemail.org I am creating a mailing list specifically for fatigue. Topics will include rainflow cycle counting, spectral methods, applications, etc. My current fatigue offerings are posted at: https://blog.vibrationdata.com/?s=fatigue&submit=Search Also, I am… Read more
Here is a paper: spectral_methods_MILHDBK5J.pdf Conference Version: 56663Irvine.pdf Conferences Slides: Irvine_Toulouse.pptx * * * The example problem in the paper was performed via the Matlab software posted at Matlab GUI package * * * See also Fatigue Damage for a Stress Response PSD Rainflow Fatigue Cycle… Read more
Structural Analysis Engineer – Loads & Dynamics 3/4 ApplyJob ID 1600001438Date posted 01/29/2016 Location Huntsville, Alabama, United States Job Description The Space Launch System (SLS) program with NASA will restore the nation’s capability in manned access to space, including destinations beyond Earth orbit. First flight will occur… Read more
Here is a preliminary version of a paper that I am going to present at conference in the UK, July 26. Multiaxis Rainflow Fatigue Methods for Nonstationary Vibration. Extended Slides: Irvine_multiaxis_fatigue.pptx Abbreviated Conference Slides: Irvine_multiaxis_fatigue_RASD_revA.pptx The conference is: MOVIC & RASD 2016 See also: Rainflow Cycle Counting In-plane Rectangular Plate… Read more
I have written a function for calculating the natural frequencies and modes shapes of a rectangular plate undergoing in-plane vibration via the finite element method. The function is included in the software posted at in the Matlab GUI package. The function can be accessed via:… Read more
Kinetic & strain energy formulas can be used as a basis for Rayleigh-Ritz or finite element analysis of vibrating structures. Equations for common structures and loading conditions are given in strain_energy.pdf The cases include: Uniform Bar under a Constant Axial Load Bar under a General Axial… Read more