Wayne Tustin is a pioneer in the field of shock and vibration training. I have had the opportunity to learn from him at several IEST meetings and other conferences. He taught me the meaning of SRS (G) and PSD (G^2/Hz) units, when I was… Read more
I recently flew as a passenger in a CRJ900 jet similar to the one shown in Figure 1. This aircraft has two GE CF34-8C5 engines, as shown in Figure 2. This engine has two high pressure axial flow stages that drive the N2 compressor, and… Read more
Update: Spacecraft On-Orbit Microvibration & Jitter Slides Introduction Spacecraft must withstand vibration from pre-launch transportation and from powered flight. The spacecraft is not powered during these events. In addition, a spacecraft must withstand “microvibration” or “jitter” from its own moving parts once it reaches orbit… 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) * * * Also quoted by: President Thomas S. Monson, BYU Devotional Be a Light to the World, November 1, 2011 *… 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
Method 1 Secondary & Component loads can be specified in the form of a Mass-Acceleration curve as described in: NASA-STD-5002, Paragraphs 4.2.1.2, 5.3.2, 5.4. The Mass-Acceleration curve can be derived from measured flight or test data, or analytical loads. Care must be taken to avoid… 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
NASA-STD-5002, Load Analyses of Spacecraft and Payloads, 1996 5.3.2 Transient load analysis (excerpt) Statistical variation of parameters governing the forcing functions is accommodated by generating multiple cases of forcing functions for a single flight event. After all cases are analyzed, the maximum transient load is… Read more
Deuteronomy 5 [13] Six days thou shalt labour, and do all thy work: [14] But the seventh day is the sabbath of the LORD thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, nor thy manservant, nor… 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