Analysis of acoustic emission signal generated by timber under load

The nature of acoustic emission (AE) signal depends on the character of the wave source (deformation or crack of the material) and properties of the material. In the case of wood materials the species, anisotropy and moisture content have also significant influence on the AE wave propagation through the material. To better understand the processes inside the specimen under load both the deformation and AE signal were measured. The acoustic emission signal was preamplified and recorded using Vallen AMSY-5 AE measurement system. The recorded data were analysed using Fourier transform. The results have proved significant differences between specimens of respective species (beech and spruce wood). AE signal monitoring makes possible to determine the allowable load for a particular specimen without any danger of permanent damage.