Vibration measurement technology: Monitoring of shocks, oscillations and vibrations

SEMEX-EngCon offers solutions for measuring vibration emissions, i.e., the effects of vibrations on people and structures according to DIN 45669. Due to regional differences in geology, infrastructure, culture, as well as technical and legal requirements, different limit values ​​and assessment criteria are defined.

Vibrations are characterized by a multitude of parameters that can also change dynamically over an observation period (exposure duration). Displacement (deformation), velocity (speed), and acceleration are measurable quantities that can be recorded using suitable sensors and used for evaluation and assessment.

In structural dynamics and serviceability testing, measuring the velocity has become particularly established as a suitable quantity, as it is directly related to the kinetic energy and modal stress to which a structure is subjected. It is typically converted into a measurable electrical voltage using a geophone and digitized for further processing.

Several standards and guidelines are based on the evaluation of various parameters of the measured vibration velocity. The following regulations are supported by SEMEX-EngCon:

In some vibration applications, vibration acceleration is the preferred measurement. Vibration acceleration allows for a more nuanced assessment of human perception (e.g., tactile threshold or arousal threshold). Several technologies are available for this purpose. SEMEX-EngCon uses MEMS accelerometers.

SEMEX-EngCon supports the following standards and guidelines, based on the evaluation of various vibration acceleration parameters:

Due to the inherent low-frequency limitations of geophones, accelerometers are preferred for large structures such as towers, skyscrapers, bridges, dams, wind turbines, etc., to reliably measure vibrations below 1 Hz. The dynamic properties of these critical structures are often described using response spectra. Such critical structures are not only subject to natural vibrations (ground movements, earthquakes) but can also induce vibrations themselves, which are perceived as unpleasant in the surrounding area or have a critical impact on other structures.

Induced vibrations are also playing an increasingly important role in the generation of renewable energy. For example, induced vibrations can be measured in geothermal and wind power plants and have sometimes led to perceptible tremors. To maintain acceptance in the surrounding communities, work processes are accompanied and, if necessary, controlled by monitoring of tremors, vibrations, and oscillations.