On a very windy day in November 1940, the Tacoma Narrows bridge went into violent torsional twisting and shook itself apart. This underlines the strong influence of vibrations on buildings.
Vibrations of buildings can have many causes. The resulting dynamic load does not only compromise the people in the building but can also lead to fatigue of the building’s basic structure and can even be critical for its stability. The current trend towards more and more slender and light buildings aggravates this problem even further.
Vibration measurements help to ensure the stability of buildings and to identify damage and dangerous alterations.
Polytec’s non-contact laser vibrometers are of enormous help, as they allow a highly precise measurement of low frequent vibrations and displacements in the micrometer range over long distances.
"Metro Testing Laboratories Ltd. has successfully used Laser Vibrometer systems from Polytec for the measurements of natural frequencies and modal analysis of stay cables. Polytec’s equipment is extremely easy to use, rugged for field usage and provided a great value for our projects. The data provided helped to analyze tension forces and vibrational behavior of bridge components in a very efficient way.
Polytec’s engineering support provided us with a service level of excellence we can only recommend further. We are looking forward executing more projects with Polytec’s equipment to improve the safety of our infrastructure."
Marcus Schmieder, M.IE&M, NDT Specialist Metro Testing Group, BC, Canada
- Non-contact measurement over long distances: just point and measure!
- Fast, easy setup of the system in minutes
- Measuring vibration from 0 Hz
- Small laser spot size for precise targeting – even on stay-cables, frameworks or girder masts
- Measuring even on rusty or dirty surfaces
- ±10 V BNC-output for analysis of measurement data with any measurement system
- Condition monitoring of buildings and industrial installations
- Determining Eigen frequencies
- Validating finite element simulations
- Risk analysis of bridges
- Determining cable tension force in cable-stayed bridges
- Characterizing concrete materials