A stress wave based approach to NDE of logs for assessing potential veneerquality. Part 1. Small-diameter ponderosa pine

Longitudinal stress wave nondestructive evaluation (NDE) techniques have be en used in a variety of applications in the forest products industry. Recen tly, it has been shown that they can significantly aid in the assessment of log quality, particularly when they are used to predict performance of str uctural lumber obtained from a log. The purpose of the research described i n this report was to investigate the use of stress-wave-based techniques fo r assessing the potential quality of veneer obtained from logs. Sixty-two p onderosa pine veneer blocks from 22 tree-length logs were nondestructively evaluated using longitudinal stress wave techniques. Stress wave transmissi on times were measured on both tree-length logs and veneer blocks. They wer e then rotary peeled, and the resulting veneer was dried and ultrasonically graded using commercially available grading equipment. The quality of the veneer, as determined by ultrasonic grading, was then compared with the non destructive measurements of the logs from which they came. A strong relatio nship was found to exist between log and veneer nondestructive assessments.