IDENTIFICATION OF THE MECHANICAL PROPERTIES OF PARTICLEBOARD BY DIGITAL IMAGE CORRELATION TECHNOLOGY

As a kind of artificial material, the surface porosity of particleboard makes the sticking process of strain gauge very difficult, and the measurement accuracy is affected directly by the amount of glue. Digital image correlation technology based on image analysis before and after the specimen deformation is used to identifier the mechanical parameters of particleboard. Compared with the traditional method of sticking strain gauge, this technique has the advantages of high accuracy, non-contact and full field measurement. The “transverse isotropic” model is considered to simulate the mechanical behavior of particleboard. Therefore, the elastic tensor characterizing the mechanical properties of materials depends on five independent elastic parameters: Young’s modulus (E^L, E^T) and Poisson’s ration (ν^L, ν^T), respectively, in the longitudinal and transversal directions, and shear modulus G^L in all planes around the symmetry axis. In order to achieve this measurement process, a sheet of particleboard was cut into a batch of beam samples which were then applied to the three-point bending test. By comparing the measured displacement of grid nodes with the analytical solution based on Timoshenko’s beam theory in the region of interest, and through the application of the finite element model updating method, 4 elastic parameters E^T, G^L, E^L and ν^L were successfully measured. The measured material parameters are very close to reported values in literatures. The measurement method proposed is simple and easy to perform, which can be extended to the measurement of elastic parameter of anisotropic materials.