For the vibrations testing, a low-force shaker for payloads up to 25kg is used. The Brüel & Kjær LDS V555 enables vibrations of frequencies up to 2400 Hz and accelerations up to 100g when empty. With the test jig and sample attached, the maximum load achievable is limited to 55g. A reference accelerometer is screwed on the test jig, enabling active control of the frequency and the acceleration.
Finally, the response of the experiment is set to be the number of mechanical shocks at 4,500g necessary to lead to a complete failure of the sensor. The shock testing machine, a Shinyei PST-300, is made of a pendulum, on the backplate of which the sample is fixed . The pendulum can be lifted at a certain angle and then released, leading it to fall and come hit a bumper placed at 0°, with a given kinetic energy. The bumper can be chosen of different materials in order to cover a range of 5 to 10,000g, with a 2% variation over reproducibility and a reference accelerometer acquires the magnitude of the shocks for control.
Test plan
A Hadamard matrix for 23 runs is obtained from Matlab by using the appropriate functionX=hadamard(8)
. The names of the corresponding samples are indicated next to each line: