There is a widely-taught principle in my church that “Obedience is the first law of heaven.” This may have been an extrapolation from Alexander Pope’s quote that “Order is heaven’s first law.” But discernment must precede obedience. The Lord placed Adam and Eve in the… Read more
Aerospace pyrotechnic shock response spectrum (SRS) specifications are almost always given with an amplification factor Q=10 Corresponding time history waveforms for the base input acceleration are almost never given with the specifications Users are allowed to synthesize their own waveforms to satisfy the SRS for… Read more
Shock and vibration analysis can be performed either in the frequency or time domain The time domain method requires more computation time but is much better suited for transient and nonstationary excitation Time domain methods are also better for rainflow fatigue cycle counting Students should… Read more
We are not human beings having a spiritual experience; we are spiritual beings having a human experience. – Pierre Teilhard de Chardin (1881-1955) Quoted by: President Thomas S. Monson, BYU Devotional Be a Light to the World, November 1, 2011 * * * * *… Read more
“In our friendly neighbor city of St. Augustine, great flocks of sea gulls are starving amid plenty. Fishing is still good, but the gulls don’t know how to fish. For generations they have depended on the shrimp fleet to toss them scraps from the nets.… Read more
These are the generations of the heavens and of the earth when they were created, in the day that the Lord God made the earth and the heavens. Genesis 2:4 * * * In rabbinic conception, Adonai “Lord” represents the attribute of mercy, while Elohim… Read more
The punch file method may be used to extract the mass & stiffness matrices from Nastran models. The format is awkward since zero terms are not stored. Also the matrices are assumed to be symmetric, and the upper triangular portion above the diagonal is not… Read more
A sound file from the attack on the U.S. Embassy in Cuba has now been made available on the Internet. I did a spectral analysis of this file using my Matlab GUI scripts. The sound source is still unknown. The attacks have caused hearing, cognitive,… Read more
NASA SP-8072 Acoustics Loads Generate by the Propulsion System (Alternate SP-8072 link) The liftoff analysis has been added to the GUI package at: Vibrationdata Matlab GUI The function can be accessed via: >> vibrationdata > Miscellaneous Functions I > Acoustics Vibroacoustics & SEA > acoustics >… Read more
This post is a work-in-progress… Combined Ascent Loads for Launch Vehicle Analysis Equivalent Axial & Line Loads for Launch Vehicles Launch Vehicle and Spacecraft Primary Structure Response to High Frequency Shock and Vibration – Tom Irvine Explore more in our Spacecraft Dynamics Knowledge Hub: View… Read more