Materials Research & Mechanical Engineering
Laser vibrometry is an ideal tool for the measurement of structural dynamics and for non-destructive flaw detection in all kinds of materials, parts and components. Engineering applications include monitoring of wind turbines, analysis of building vibration and displacement, and preventing cable-stayed bridges from resonance failure. Geological applications include detection of land mines, rock failures and earthquake-induced defects in concrete.
Very High Cycle Fatigue (VHCF)
An innovative ultrasonic testing facility for tension-compression experiments was developed at the Institute of Materials Science and Engineering (WKK) at the University of Kaiserslautern in Germany. Polytec’s 3-D scanning laser vibrometer was used to measure the eigenfrequencies and eigenmodes and verify the finite element model. The work done in cooperation with Polytec illustrates possible applications of 3-D scanning vibrometry in the field of ultrasonic fatigue testing of metals. 3-D scanning vibrometry is also capable of non-contact local strain measurement with a high spatial resolution and offers an alternative to strain gauges for evaluation of high mechanical stresses along the gauge length during ultrasonic fatigue testing.
High Frequency Stress and Strain Measurements During Ultrasonic Fatigue Testing with 3-D Scanning Vibrometry (PDF)
(F. Balle et al., InFocus 2/2011)
Monitoring of Wind Power Plant Vibrations
Preventative maintenance, or condition monitoring, on wind power plants is often done with the aid of vibration sensors which are placed along various sections of the drive shaft. In contrast, laser vibrometers are a powerful tool for remote, non-contact vibration monitoring. Measurements can easily be made from the ground.
Measurement of Security Features on Banknotes
Various security features on banknotes are intended to protect against counterfeiting and to help in recognizing counterfeit notes. A common characteristic is raised print – the result of a special printing process. This is what typically gives banknotes their unique feel, whereas the printing height of counterfeit notes is often quite flat and difficult to sense. The inspection of print height can be done quickly and easily with white light interferometry.