Wooden Surface Investigation: an Optical Approach Based on Shadow Moiré

Abstract

The interest in the mechanical behaviour of wood is a very important task due to the increasing role played by wood structures in modern architecture as well as its applicability in restoration of ancient buildings. The behaviour of wooden surfaces experiencing variable humidity conditions is of great importance both with concern to performances of wooden building’s structures and to ensure correct restoration and conservation of art works like wooden sculptures and panel paintings [1]. In literature there are only a few studies dealing with the influence of moisture on the physical properties of wood [1,2]. The characterization of wooden behaviour related to changes in the humidity level could make easier restoration and preservation of wooden artefacts. In the last years, the increasing development of technology allowed the application of non contact wholefield measurement techniques. These techniques could play a fundamental role in the analysis of the mechanical behaviour of materials such as plastic and wood. Among these techniques: Digital Image Correlation, Structured Light, Electronic Speckle Pattern Interferometry (ESPI) [3]. Recently some real-time 3D wood panel surface measurement using laser triangulation [4] and light shadow scanning [5] have been proposed.