The top figure is the time history from the El Centro earthquake, North-South horizontal component. The middle is the corresponding Waterfall SRS with 4 second segments and with 50% overlap. The bottom is the spectrogram. The Waterfall SRS is calculated by first taking the complete… Read more
I am currently researching IEEE Std 693… One of its recommended shaker test methods for power equipment is to use a “sine beat” acceleration time history. The main frequency is selected as the equipment’s natural frequency. The minimum number of beats is 5 with a… 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
I posted a newsletter at: http://www.vibrationdata.com/Newsletters/March2012_NL.pdf The topics are: James Webb Space Telescope Isolation The Prandtl-Glauert Singularity Seneca Guns Loudest Stadium Crowd Please also see my profile at: http://www.nasa.gov/offices/nesc/academy/Tom_Irvine_bio.html Tom Irvine
I have posted the January 2012 Newsletter at: http://www.vibrationdata.com/newsletters.htm The topics are: Slow Earthquakes Rumbler Siren Shepard Tones Toadfish Mating Call There are seven accompanying sound files and one Matlab script. Please let me know if you have any questions. Thank you, Tom Irvine