Vibration test

The vibration test is a test method for examining the loads that occur due to vibration and their consequences in individual components and complete systems. This procedure is primarily used to test the mechanical strength and to ensure the function of technical systems under vibration stress.

Products that are exposed to vibrations in their later use are also subjected to a vibration test as part of the prototype qualification.

application

A typical example are electronic control units in cars. When driving, these are inevitably exposed to vibrations of various frequencies and amplitudes (e.g. tires , bearings , road conditions, engine vibrations due to inertia forces). These vibrations can lead to failure (breakage of external fastening straps or electronic component connections on the circuit board) of the control unit due to insufficient fatigue strength ( Wöhler test ).

So that such a fault does not occur in the vehicle during operation, the vibration loads of the later application are simulated on so-called shakers. Such a shaker works on the principle of "moving coil in a magnetic field" and converts an electrical signal into a mechanical deflection. The test item is attached to the shaker by means of a clamping device that is usually specially made. Typical frequency ranges for vibration testing of automotive electronics are 10–1000 (2000) Hz. Typical acceleration values are 1… 3 g for body construction and 8… 28 g for engine construction.

Hydraulic shakers, which can also generate significantly larger amplitudes, are used to test very low-frequency vibrations, such as for earthquake simulation. Such earthquake simulations are z. B. carried out when testing telephone switching systems.