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
I have added batch processing as an option for time histories as shown above. I will add more options in upcoming revisions. The Vibrationdata Matlab GUI package is given at: Vibrationdata Matlab Signal Analysis Package Here are some sample input files for practicing batch processing: batch_sample.mat… Read more
Rainflow fatigue cycles can be easily calculated for a single-degree-of-freedom subjected to a sine or sine sweep base input. The reason is that each pair of consecutive positive and negative response peaks forms a half-cycle. The relative fatigue damage can then be calculated from the… Read more
PowerPoint File: webinar_22_integration_part_2.ppt Audio/Visual File: NESC Academy Integration and Differentiation – Recommend viewing in Firefox with Sliverlight Plugin * * * ASCII Text Data Files: navmat_spec.psd two_wheeled_trailer_vertical.txt * * * Matlab script: Vibrationdata Signal Analysis Package * * * Python version: Unit_22_integration_part_2_python.ppt Python Signal Analysis Package GUI… Read more
The Pierson–Moskowitz (PM) spectra is an empirical relationship that defines the distribution of energy with frequency within the ocean. The result is given as a wave height power spectra density. Developed in 1964, the PM spectrum is one of the simplest descriptions for the energy… Read more
Here is a paper. Estimating Fatigue Damage from Stress Power Spectral Density Functions: estimate_fatigue_psd.pdf Note that the duration for the example in the paper was 600 sec. * * * This following Matlab program calculates the cumulative rainflow fatigue damage for an input stress PSD… Read more
PowerPoint File: Unit_21_integrate_differentiate.ppt Audio/Visual File: NESC Academy Integration and Differentiation, Part 1 – Recommend viewing in Firefox with Sliverlight Plugin * * * Pyrotechnic Shock File: pyro_test.txt – time(sec) & accel(G) * * * Matlab script: Vibrationdata Signal Analysis Package * * * Python Version: Unit_21_integrate_differentiate_python.ppt Python… Read more
PowerPoint File: webinar_19_digital_filtering.ppt Audio/Visual File: NESC Academy Digital Filtering – Recommend viewing in Firefox with Sliverlight plugin * * * Python version: webinar_19_digital_filtering_python.ppt Python script: Python Signal Analysis Package GUI * * * Data: sm.txt – unscaled relative displacement vs. time (sec) * * * Reference… Read more
PowerPoint File: webinar_18_force_VRS.pptx Audio/Visual File: NESC Academy Force_VRS * * * Python version: webinar_18_force_VRS_python.pptx – Recommend viewing in Firefox with Sliverlight plugin Python script: Python Signal Analysis Package GUI * * * Reference Papers: The Steady-state Response of Single-degree-of-freedom System to a Harmonic Excitation Force: sforce.pdf… Read more
PowerPoint File: webinar_17_SDOF_force.pptx Audio/Visual File: NESC Academy SDOF – Response to Applied Force – Recommend viewing in Firefox with Sliverlight plugin * * * Reference Papers: T. Irvine, Machine Mounting for Vibration Attenuation, Rev B, Vibrationdata, 2000 link Bruel & Kjaer Booklets: Mobility Measurement link Modal… Read more