PROGRESS IN MECHANICS OF MATERIALS BY USING LASER SPECKLE METHOD

摘要

The aim of this paper is to present some examples of the use of laser speckle method for the study of composite and polymer mechanical behaviour. A specific mechanical device has been designed in order to realise in-situ singly exposed speckle photographs. It is thus possible to obtain quite rapidly and easily in-situ displacement measurements, that is to say on the tensile testing machine, and with a good accuracy. This method has been applied to check and improve mechanical constitutive laws of structural composite materials. It has also been applied to validate new mechanical tests, for example shear tests, by verifying the uniformity of strain fields in the specimens. Moreover, this method allowed us to characterise strain fields around crack lips in polymers.