Here is Matlab script for plotting the MIL-STD-810G, Figure 514.6D-2, Category 13, Propeller Aircraft Vibration Exposure PSD, including the overall GRMS level. propeller_psd_grms.m * * * See also: Bombardier Q-400 Turboprop Acoustics Aircraft Shock & Vibration – Tom Irvine
This Matlab script calculates the one-sided, full amplitude FFT of an acceleration time history: FFT_VD.zip It gives the output FFTs in acceleration, velocity and displacement formats. It is useful for evaluating machine and pump vibration where there are distinct sine tones and harmonics. The main… Read more
Question from one of my readers If equipment is normally isolated in service, should HALT vibration testing be performed with or without isolators since the intent of this testing is to find operational and structural limits regardless of the real environment. Answer from Steve Brenner… Read more
Consider a component which is to be subjected to a shock test using a shaker table. The test specification for this example is a Shock Response Spectrum (SRS). The control computer must synthesize a time history for the test. The typical method is via a… Read more
Time Waveform Replication (TWR) for shock testing on shaker systems has been receiving some attention in MIL-STD-810G and elsewhere. The goal is to test components to measured field time histories for realism. I did some related work with NASA’s Robin Ferebee a few years ago,… Read more
Pyrotechnic devices such as linear shaped charge and frangible joints are used for stage and fairing separation in launch vehicles. These devices generate high-frequency mechanical shock energy. Avionics components mounted in the vehicle must be designed and tested to withstand this shock energy. Thus, ground… Read more
The European Cooperation for Space Standardization http://www.ecss.nl/ Download: ECSS-E-ST-10-03C, Space Engineering: Testing Spacecraft Mechanical Loads Analysis Handbook: ECSS-E-HB-32-26A_19February2013 Slide summary: ESA_mechanical_loads_handbook_part_1 * * * SMC-S-016, Air Force Space Command, Space and Missile Systems Center, Standard Test Requirements for Launch, Upper-Stage and Space Vehicles, 2014 Download… Read more
Question: MIL-STD-810G, Method 526 Rail Impact, outlines the physical test of an actual system at 4, 6, and 8 mph. Is there an equivalent laboratory shock test for equipment which is to be transported via railroad car? Answer 1: from Tom Irvine U.S. Army TB… Read more