Calibração da técnica de moiré aplicada a perfilometria de protótipos mecânicos

Abstract

Profilometry is a measurement technique widely used in map and relief graphic construction, being applied to vast areas of knowledge. The aim of the present investigation was to introduce a calibration method applied to a moiré technique in experiments of mechanical archetypes, with low cost and flexibility, due to the need for supplying demands from both industry and mechanical archetype development for non-invasive techniques. The moiré technique basically consists of the comparison of two periodic structures. One of them follows the behavior of the object surface (reticulum model - Rm) and the other one is kept constant without deformation, working as a reference plane (reference reticulum - Rr). The light that passes between the reticulum overlaps and forms a moiré standard, also called moiré fringe which behaves as sinusoidal waves. In the present calibration tests, a relief cone was used to determine a correction constant in the generated maps. The technique was applied to draw the profile of a computer mouse, and to determine deformation on a metallic blade, mounted over a deformation test table. The proposed methodology for the calibration applied to the moiré technique showed to allow the construction of maps with maximum resolution of hundredths of millimeters. Results also showed that the technique might be used in applications with lower levels of precision as well.