Fracture initiation and progress in wood specimens stressed in tension

摘要

Clear spruce wood specimens with 30, 20, 10, and 5° slope of grain were subjected to in-situ tensile failure tests in order to study fracture initiation and propagation. Fracturing of the specimens was carried out inside SEM with a bending and a tension device, respectively. The bending and the tension specimens consisted of two to three growth rings. Fracture process in 30°-, 20°-, and 10°-speciments was quite uniform but differed from that of 5-°-specimens. There was no difference between bending and tension specimens.