Evaluation of Internal Cracks and Collapse in Poplar Wood (Populus nigra) during a Conventional Drying Process with Ultrasonic Inspection

Abstract

In this research, internal cracks and collapse of wood, formed during drying process, were measured using ultrasonic inspection. For this purpose, seven poplar (Populus nigra) small blocks were dried, according to a time-based schedule. Ultrasonic waves’ propagation velocity was measured at both parallel and perpendicular to grain directions, using Sylvatest ultrasound device, during kiln drying process. Results showed that in all dried blocks, waves’ propagation velocity in the parallel direction was higher than in the perpendicular direction to grain. Ultrasonic waves’ propagation test for non-destructive identification of internal cracks, which occurs in wood during drying process in the parallel direction, was more successful compared to the perpendicular direction. Using ultrasonic waves’ propagation test for detection of collapse that occurs in wood during drying process was not useful.