Explanation for reduction of mechanical properties of Japanese larch timber kiln-dried by the high-temperature setting method based on fractography observation

对日本落叶松木材在4种干燥方式和3种暴露条件下力学性能下降的原因进行了拉伸试验，并对断裂表面进行了扫描电镜观察。与杉木相比，落叶松试样脆性较多，高温定型方法使落叶松木材脆性增大。结构木材和小型透明试件的弯曲试验结果表明，干燥方法对两者的力学性能都至关重要，但暴露对其影响不大。

ensile tests were conducted, and the fracture surfaces were observed with the SEM to explain for reduction of mechanical properties of Japanese larch timber under four drying methods and three exposure conditions. Brittle cases were often observed in Japanese larch specimens compared with Japanese cedar, and the high-temperature setting method brought more brittleness for Japanese larch timber. The results of bending tests for structural timber and small clear specimens indicated that drying methods was critical to mechanical properties of both, but exposure had little effects on them.