Thermal strain analysis of composite materials by electronic speckle pattern interferometry

This study discusses a non-contact optical technique (electronic speckle pa ttern interferometry) that is well suited for thermal deformation measureme nt without any surface preparation and compensating process. Fiber reinforc ed plastics ([0](16), [0/90](8s)) were analyzed by ESPI to determine their thermal expansion coefficients. The thermal expansion coefficient of the tr ansverse direction of a uniaxial composite is evaluated as 48.78 x 10(-6)(1 /degrees C). Also, the thermal expansion coefficient of the cross-ply lamin ate [0/90](8s) is numerically estimated as 3.23 x 10(-6) (1/degrees C) that is compared with that measured by ESPI.