Reliably testing fatigue behavior
Reliable material parameters are essential if simulation models are to make safe predictions – especially when durability of the service life is being calculated. Structures in automotive engineering, medicine and energy technology are exposed to load changes of more than ten million cycles over the course of their expected lifetime –due to either high-frequency stress or a long operating time of up to 30 years. This range is referred to as the very high cycle fatigue (VHCF) range and extends far beyond the range of classic S-N curves. Extensive knowledge of the fatigue behaviour of the materials used is thus of vital importance if these high-performance components are to operate reliably in the VHCF range. To be able to go through the high load changes of 1010 in a reasonable time period of less than one month, the samples are offset in resonance vibration at frequencies in the kHz range.
Polytec Magazine
Validation on bridge superstructures
A modal-based monitoring system
Measuring stress and strain and Eigen modes
With regard to verifying the simulated sample model, Polytec 3D Scanning Vibrometers provide a direct way of measuring the true fatigue sample’s Eigen modes and Eigen frequencies. Another potential application lies in the field of high-frequency stress and strain analysis, since contact measurement methods such as strain gages are not suitable for this type of endurance stress. This method also comes into play for operational reliability testing of high-stress train components (wheel rims), wind turbines and ultrasonic scalpels (medical technology).
Related products
PSV QTec Scanning Vibrometer
PSV QTec Scanning Vibrometers take full-field vibration mapping to the next level with unrivalled optical sensitivity! Their innovative, patented QTec® technology uses multi-path interferometry based on infrared (SWIR) laser granting high-fidelity measurements on all surfaces from DC to 25 MHz. PSV QTec significantly reduce testing time - especially on dark, biological, rotating or moving objects, determining operational deflection shapes and Eigenmodes for NVH, acoustics, structural dynamics, ultrasonics, FEM validation and NDT.
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.
Measurement service & rentals
Our engineering services cover a wide range of applications, either onsite or in our laboratories. Ask for our PolyXperts, rent cutting edge laser measurement equipment and benefit from individual support for your projects. Our experienced application engineers are pleased to help, measure and test for you. For comprehensive studies, rent the RoboVib® Structural Test Station
