Temporal Moments

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

Webinar 42 – Shock Special Topics

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

Pyrotechnic Shock Propagation

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

Webinar 27 – SRS Synthesis

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

Webinar 26 – Pyrotechnic Shock, part 2

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

Webinar 25 – Pyrotechnic Shock

PowerPoint File:  webinar_25_pyrotechnic_shock.pptx Audio Visual File: NESC Academy Pyrotechnic Shock – Recommend viewing in Firefox with Sliverlight Plugin * * * Data: rv_separation.dat – time (sec) & accel (G) * * * Matlab script: Vibrationdata Signal Analysis Package * * * Python version:  webinar_25_pyrotechnic_shock_python.pptx Python… Read more

Webinar 24 – Seismic Shock

PowerPoint File:  Webinar_24_Seismic_Shock.pptx Audio/Visual File: NESC Academy Seismic Shock – Recommend viewing in Firefox with Sliverlight Plugin * * * Data:  elcentro_NS.dat  – time (sec) & accel (G) * * * Matlab script: Vibrationdata Signal Analysis Package * * * Python Webinar_24_Seismic_Shock_python.pptx Python script: Python… Read more

Webinar 23 – Classical Shock Pulse

PowerPoint File: Webinar_23_Classical_Shock_Pulses.pptx Audio/Visual File: NESC Academy Classical Shock Pulse – Recommend viewing in Firefox with Sliverlight Plugin * * * Matlab script: Vibrationdata Signal Analysis Package * * * Python Webinar_23_Classical_Shock_Pulses_python.pptx Python Signal Analysis Package GUI * * * See also: SRS Educational Animation See… Read more

SRS Synthesis Files

Here is a sample SRS specification.  The ramp is a constant velocity line with slope = 6 dB/octave. SRS Q=10 fn(Hz) Peak Accel (G) 10 10 2000 2000 10000 2000 Here is a set of files which satisfy the SRS. ASCII text:  srs2000G.zip The files… Read more