Fundamental study on simple compression test and stress relaxation characteristics of wood

In recent years, as the service lives of timber structures have increased, there has arisen a need for better comprehension of how the seismic performance of such structures can be changed via wood stress relaxation. Herein, the authors report on their study of wood-bolted joints, and describe the effects of imposition time on wood stress relaxation. More specifically, imposition times of 1, 3, 5, and 10 s. were set and imposed via a precision universal/tensile tester (PUTT), after which 100 s simple stress relaxation tests were conducted. The results were then compared to wood-bolted stress relaxation tests previously conducted by the authors. The results suggest that the wood stress relaxation is only slightly affected by imposition speeds and that wood-bolted joint stress relaxation can be reproduced via simple stress relaxation testing.