Cedip Infrared Systems's Silver 450M IR camera is being used by Snecma (Villaroche, France), a leading manufacturer of aero-engines, for remote non-contact fatigue testing of engine turbine blades
Snecma, a Safran Group company, designs, develops and produces engines for civil and military aircraft, launch vehicles and satellites.
In order to improve the design of its aero-engines, engineers at Snecma sought to better understand the behaviour of differently treated engine turbine blades when subjected to extreme vibration testing.
To simulate vibration conditions researchers mounted a turbine blade on a fixed, rigid support and subjected it to powerful pulsated air blasts considerably in excess of what would be encountered in an aero-engine even in extreme use.
Crack propagation was induced by gradually increased the frequency of the intense air blasts to the resonant frequency of the turbine blade.
Using a Silver 450M thermal IR camera, Snecma engineers were able to pinpoint the exact stress limit of a range of differently treated turbine blades as the appearance of a crack is proceeded by a localised heating effect.
During crack propagation the temperature at this point rises by several hundreds of degrees.
However as the point is very small and the crack propagation process very fast (a few milliseconds) this places great demands on the IR camera in terms of the need for excellent spatial definition, high frame frequency and large dynamic range (ambient to 800C).
The Silver 450M is specifically designed for the most demanding users of IR technology who want to perform thermal imaging at ultra fast frame rates with the highest sensitivity and accuracy at an affordable cost.
Incorporating the latest ROIC technology the Silver 450M's 320x240 pixel format InSb detector delivers an outstanding 400Hz full frame rate while maintaining extraordinary linearity and high sensitivity.
Offering a sub-array windowing mode with integration time adjustable in 1us increments and smart external triggering capability the Silver 450M is able to synchronise image capture to even the most transient events.
Incorporating an integral optical front end, Snecma engineers were able to precisely focus on microscopic areas of turbine blades then using the bayont mounting quickly change the lens to adapt the field of view for turbine blades of different sizes.
Transferring images at a full 14-bit dynamic range via a Camlink interface to a remote PC enabled engineers to record a complete 15 minute experiment with remarkable thermal discrimination from ambient to 800C.
Using additional functionality within the Silver 450M camera software, Snecma were able to integrate IR data with readings from strain guages also installed on the turbine blades under test.
Cedip Infrared Systems develops, designs, manufactures and markets high performance infrared cameras and systems for industrial, research, surveillance and security organisations.
