A method of strain measurement at high temperatures (up to 2 600℃) for carbon/carbon composites by digital speckles was introduced. The samples in the test were sprayed with tungsten powder as the target speckles. Then the samples were heated to the test temperature. The samples emitted bright light by carbon/carbon composites and tungsten. After the narrowband filtered the light in the tension test, the light by carbon fiber was filtered and the light by tungsten was reserved. Then the image acquisition was performed. It is found that the image processing can reflect the strain state, reconstruct the profile of the specimen surfaces vividly and reproduce the deformation field of the strain field. For critical points, the image processing can also track their trajectory and calculate their strain at any time and arbitrary displacement. It also shows that the digital speckle correlation method is an accuracy measurement. Furthermore the method can be utilized to various mechanical sites. ©, 2014, Journal of Solid Rocket Technology. All right reserved.
