Stentor Satellite Equipment mounted in satellites must withstand acoustic-driven random vibration at liftoff and during the transonic and maximum dynamic pressure phases of flight. The equipment must be designed and test accordingly. The equipment is mounted on shaker tables for the random vibration testing,… Read more
Figure 1. A320 Takeoff I recently flew as a passenger in an A320 similar to the aircraft shown in Figure 1. Figure 2. Time History Plots The takeoff vibration is shown in Figure 2 for the lateral and vertical axes. The aircraft went airborne… Read more
Certain equipment must be designed and tested to withstand external vibration excitation. This is common in the military, naval, aerospace and other industries. The equipment is typically mounted on a shaker table and subjected to base excitation. The input may be random vibration if the… Read more
Years ago, I had the opportunity to perform hands-on shaker table testing, mostly for avionics components. That was a great learning experience. Alas, that opportunity has gone, but I am still involved writing software and providing training for test engineers. LDS was one of the… Read more
The NASA/JPL Environmental Test Laboratory (ETL) developed and built a tunable beam shock test bench based on a design from Sandia National Laboratory many years ago. ETL has been using this test system successfully since October 2008. The excitation is provided by a projectile driven… Read more
I recently rode in the above French TER, Electric Train, Model Z 24500, Lyon to Annecy. A sample accelerometer time history is shown above. The sensor was mounted on a passenger car floor, a Slam Stick X, sampled at 400 samples/sec. The spectrogram of the… Read more
I recently flew as a passenger on a E190 similar to the one in the top image. The landing shock is shown in the bottom image. The data was recorded on a Slam Stick X, sampled at 400 samples/sec. The initial set of peaks have… Read more
Image Courtesy of Justin Kane I recently flew as a passenger on a A330-200 similar to the one in the image. I used a Slam Stick X Vibration Data Logger to measure the landing shock, with the sensor mounted on the cabin floor. The acceleration… Read more
Ideally, a modal test on a structure would be performed with completely free boundary conditions. This configuration can be approximated by mounting the structure on compliant air cushions, or by suspending it with elastic cords, so that the mounted natural frequency is much smaller that… Read more
I recently flew as a passenger on a A320 similar to the one in the image. I used a Slam Stick X Vibration Data Logger to measure the landing shock, with the sensor mounted on the cabin floor. The resulting acceleration time history is shown… Read more