Fast and efficient determination of stress and strain distribution
Safety is the top priority in aircraft construction. With each generation of new engines developed, the fuel efficiency must be increased. Safety and efficiency also starts with the durability properties of the smallest component: the turbine blade. 3D laser vibration analysis allows fast, efficient and highly detailed assessment of stress and strain distribution with basically unlimited measurement points and a high spatial resolution, using the fine laser spot. Derived directly from the FE grid and purely visual in nature, the instrumentation costs per blade are omitted entirely. The high spatial resolution reliably shows you both the location and the value of the maximum stress value. This method is used the world over by all the leading component and engine manufacturers. Following the trend toward a lighter engine, blisks (blade-integrated disks) are used in high-pressure compressors. Coordination of the blades’ eigenfrequencies is absolutely essential for safe operation. Scanning Vibrometers quickly provide you with the necessary data for this very purpose.
Polytec Magazine
FE model correlation of a blisk
3D scanning laser Doppler vibrometry for fuel-efficient turbines
Optical stress and strain measurement for blisks and turbine blades
Bladed disk (so called blisks) or bladed rotors change their dynamic properties depending on the rotational speed. The optical derotation method is perfect if the calculation is to be adjusted using valid test data. With the measuring laser’s movement being synchronized with the turbine, one can easily extract the true operational deflection shapes from the trial. Even today, optical measuring technology is the established global tool for safety and a faster time to market in development, testing, preventive maintenance and even parts reconditioning.
Validating complex models accurately and without contact
The need to validate simulation models of complex mechanical structures has grown in importance for efficiency in the design process. This is especially true for non-linear structures (such as composite panels and jointed components) where it is critical to use an accurate full-field measurement method. This tutorial covers a how-to-guide and use-cases of Scanning Laser Doppler Vibrometry (SLDV) as a non-invasive technology to efficiently characterize critical mechanical structures. Read the full paper from the IMAC International Modal Analysis Conference.
Eichenberger J., Sauer J. (2022) Validating Complex Models Accurately and Without Contact Using Scanning Laser Doppler Vibrometry (SLDV). In: Di Maio D., Baqersad J. (eds) Rotating Machinery, Optical Methods & Scanning LDV Methods, Volume 6. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, Cham. https://doi.org/10.1007/978-3-030-76335-0_11
Related products
PSV-500 Scanning Vibrometer
The PSV Scanning Vibrometer measures vibrations on an entire surface in a non-contact and laser precise way. Its visible HeNe laser provides outstanding SNR on well-reflecting sample surfaces and is ideal for small samples and under water. This flexible measurement platform allows researchers and developers to master the most challenging vibration measurement tasks with ease – from DC to 25 MHz. Detect and visualize operational deflection shapes and Eigenmodes with this cutting-edge laser Doppler vibrometer. Upgrade or expand it to a full 3D system once your application-specific demands grow.
PSV-500-3D Scanning Vibrometer
The PSV-500-3D Scanning Vibrometer measures 3D dynamics in research and product development in a reliable and precise way. Its visible HeNe laser provides outstanding SNR on well-reflecting sample surfaces and is ideal for small samples and under water. The deflection shapes and Eigenmodes detected help you with everything from NVH, acoustic and structurally dynamic issues to ultrasonic analyses, FEM validation and non-destructive testing from DC to 25 MHz.
RoboVib
By combining a 3D scanning vibrometer and an industrial robot, RoboVib® offers you an automated measuring station for measuring everything from complex components to complete vehicle bodies. Both the amount of time required and the sources of error – especially in experimental modal analysis – are reduced significantly. So you can thoroughly test a vehicle body, for example, in just one to two days, whereas you would previously have needed weeks to even prepare for the test itself.
Further applications in aerospace
- Modal analysis
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Mode conversion from symmetric into asymmetric Lamb waves at a structural defect - Aerospace
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Aerospace research using laser vibration measurement for model validation on satellite sails
