Launch vehicle and spacecraft equipment must withstand pyrotechnic shock from stage separation and other flight events. Civil engineering structures and equipment must survive seismic events. There are many other examples where military, automotive, telecommunication and other equipment must be designed and tested to meet shock… Read more
Figure 1. El Centro Earthquake 1940, Peak Pseudo Velocity, 36.4 in/sec Launch vehicle and spacecraft equipment must withstand pyrotechnic shock from stage separation and other flight events. Civil engineering structures and equipment must survive seismic events. There are many other examples where military, automotive,… 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
My colleagues at Sandia National Laboratories have presented some conference papers recently on energy response spectrum. Here is a paper that I wrote on this topic: energy_response_spectrum.pdf Also, I have added the energy response spectrum as an option for acceleration time histories to the Vibrationdata… Read more
A typical SRS specification has a ramp and plateau. The best way to meet this specification type is with a complex oscillating pulse. In some cases, a classical shock pulse may be used, but this will cause an over-test at certain frequencies. Also, classical pulses… Read more
Temporal moments are sometimes used for shock analysis. Here is a Matlab script: temporal_moments.m References: Hemez & Doebling, From SRS to Temporal Moments J. Cap & D. Smallwood, A methodology for defining shock tests based on shock response spectra and temporal moments See also: Energy… Read more
1.Accidental Drop Shock 2.Half-Sine Shock on Drop Tower 3.Half-Sine Shock on Shaker Table 4.Waveform Reconstructions via Wavelets Slides: webinar_42_shock_topics.pptx Audio/Visual: NESC Academy Shock Special Topics – Recommend viewing in Firefox with Sliverlight Plugin * * * Matlab script: Vibrationdata Signal Analysis Package Data Sample: shaker_halfsine.txt -… Read more
The following is based on a description from Dennis Kern, NASA/JPL, which Isam Yunis, NASA Langley, referenced in a shock presentation. Shocks travel through structure as a combination of propagating waves and vibration response, with the vibration response concentrated more in lower frequencies and the… Read more
This Webinar covers two synthesis techniques 1. Wavelets 2. Damped Sinusoids PowerPoint File: webinar_27_SRS_synthesis.pptx Audio/Visual Files: Recommend viewing in Firefox with Sliverlight Plugin NESC Academy Wavelet Synthesis NESC Academy Damped Sine Synthesis * * * Matlab script: Vibrationdata Signal Analysis Package * * * See… Read more
This Webinar has two topics: 1. Aliasing in shock data 3. Saturation and spurious trend removal PowerPoint File: webinar_26_pyrotechnic_shock_part2.pptx Audio/Visual File: NESC Academy Pyrotechnic Shock II – Recommend viewing in Firefox with Sliverlight Plugin * * * Data: rv_separation_raw.txt – time (sec) & accel (G)… Read more