Caractérisation mécanique non destructive des grumes à l'aide du GrindoSonic

Details

Supervisors

Latteur, Pierre

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil des constructions, à finalité spécialisée

Abstract

enCurrently, timber is not economically competitive with other materials. One solution is to limit the various processing stages and to use the log directly as a structural element. One of the major challenges of this approach is the non-destructive determination of the mechanical properties of the full log. This thesis explores the IET method using the GrindoSonic® for characterising the axial stiffness of logs and detecting mechanical damage in a cyclic static non-destructive protocol, carried out in parallel. Before using the IET on logs, experiments on squared, cylindrical, and conical specimens were performed. These experiments have shown that the dynamic modulus is different from the static modulus and is less sensitive to damage. In the log experiments, criteria were found to target the natural frequency and 3 different wood species batches of 10 logs were tested. Of the methods tested, longitudinal resonance is the most accurate and has proven to be successful with spruce. Furthermore, possible mechanical damage can be detected by comparing physical measurements before and after the protocol. An industrial application of the IET method could be considered in sawmills, as it could be used to perform a quick, low equipment screening to exclude logs that do not have the expected stiffness.