NASA's Langley Research Center has developed an optical method for detecting displacements and strains at ultra-high temperatures during thermo-mechanical testing. This innovation will provide displacement and strain measurements in high-temperature applications where conventional measurement technologies cannot physically survive. The measurement system has operated in laboratory environments in excess of 2,800 °F.
A need exists to measure displacements and strains for materials subjected to high temperatures at or above 1,500 °F to verify a material's structural performance at those temperatures. For example, such measurements are needed for spacecraft re-entry vehicles, hypersonic flight vehicles, high temperature engine turbines, and high-performance engines.
The technology is an ultra-high-temperature measurement technique that enables the use of conventional optical methods for sensing of displacements and strains at temperatures well above those where these conventional measurement techniques have previously been applicable. The technology uses high-temperature materials that can endure an experimental high-temperature environment while simultaneously having a minimum optical aberration. Emissivity differences in these materials can be used to produce a visible pattern that can be used by conventional optical methods.