Evaluation of Thermally Modified Wood by Means of Stress Wave and Ultrasound Nondestructive Methods

The paper aimed at studying the potential of two nondestructive methods to estimate the wood mechanical properties and mass loss due to thermal treatments. In this study, a low-density tropical hardwood species Simarouba amara (marupa) was used. Forty small beams with dimensions of (25 x 25 x 400) mm (width x thickness x length) were cut from this species. Initially, the beams were nondestructively tested using stress wave and ultrasound methods. It was found that all evaluated properties of treated material could be modeled al a reasonable level (R2= 0.392 to 0.874) depending on the nondestructive method and treatment schedule used. Nevertheless, ultrasound method lilted the most suitable models for a large number of properties. It could be concluded that stress wave and ultrasound nondestructive methods presented great potential to evaluate properties of thermally treated wood material.