Abstract

SAUCEDO-ZARATE, Carlos H.; LOPEZ-LOPEZ, Máximo; SANCHEZ-LOPEZ, Carlos  and  HUERTA-RUELAS, Jorge A.. Sistema experimental para el estudio de microdeformaciones mecánicas mediante anisotropía óptica inducida. Ingenier. mecáni. tecnolog. desarroll [online]. 2010, vol.3, n.5, pp.171-178. ISSN 1665-7381.

Currently there is a scientific and technological interest to evaluate by a non-destructive and non-invasive method the mechanical performance of materials. In this paper we present the development of a multi-functional experimental setup to obtain the strain/stress state in a variety of materials such as, semiconductor heterostructures, composite materials, alloys, among others. The main purpose is to characterize strain/stress state of materials in elastic range, employing reflectance-anisotropy laser (RAL) measurements and strain gages. The system presented is able to obtain traditional strain gages measurements simultaneously with RAL signals in specimens strained with a micrometric computer control. A NI™ platform is used for signal conditioning and processing. The system is composed of an optical setup with a photoelastic modulator as a central device to measure the RAL signal, and a flexor which applies a deformation in a specimen by means of a micrometer. A correlation value 0.99 was found between the RAL optical signal and the strain gages measurements. From our results a new contact-less procedure was established to measure the microscopic strain behavior with high accuracy. The experimental setup can be employed in traditional metallic materials, composite materials, or new semiconductor heterostructures, where strain gages are difficult, if not impossible to apply.

Keywords : Reflectance anisotropy; extensometry; optic anisotropy; elastic strain; silicon (110).