DEFORMATION ANALYSIS application example

Strain measurement at High temperatures

In-situ measurement of temperatures, deformations and strains at high temperature supports the numerical model validation of ceramic matrix composites (CMC). The DLR Stuttgart develops the CMC silicon carbide fibers reinforced silicon carbide (SiC/SiC) e.g. for the high-pressure turbine of aircraft engines.

In the institute a hollow cylinder made of SiC/SiC was heated on the inner side in a burner test rig. This generates thermo-mechanical stresses due to thermal expansion and limited hoop extension.
In-situ inner and outer temperatures were measured via a pyrometer and an infrared camera. In-situ deformations were measured via Q400 digital image correlation (DIC) system consisting of blue LED lamps and band pass filters. Temperaatures have been above 1000°C.
The experiments are finally used to validate numerical simulations.

The upper image image shows the DIC measurement setup with blue LED illumination.

The lower images show the cylindrical 3D geometry and the displacement field, both measured contactless with the Q400 system.