【摘要】 运用同步辐射光源，对杉木和马尾松径、弦向切片在拉应力作用下的破坏过程进行了观察．结果显示：木材在径向拉伸荷载的作用下，易在早、晚材分界处出现裂纹，并向早材部分扩展，裂纹扩展路径不规则，在细胞壁处被终止；木材在弦向拉伸荷载的作用下，易在木射线处出现裂纹，并很快在其附近产生更多的裂纹，直至破坏。木材预制裂纹与木材纹理垂直，受顺纹拉伸荷载的作用时，裂纹尖端不沿预制方向扩展，而是顺纹扩展。木射线和纹孔对裂纹扩展起阻碍和终止作用。更多还原

【Abstract】 The micro-tensile processes of Chinese-fir and Masson pine are studied by synchrotron radiation light (SRL). It shows that the patterns of crack propagation are different in tangential and radial tensile process. In the tangential tensile process, because of stress concentration near the crack, once the wood forms a crack, more cracks will occur. In the radial tensile process, crack appears in the standard specimen first mainly in the boundary of early wood and late wood. Usually it extends to early wood. Crack tip does not propagate under tension parallel to grain when the pre-cut crack is perpendicular to grain. On the contrary, small cracks perpendicular to grain form and gather near the pre-cut crack. Obviously sliding between tracheids and intercell failure is easier to happen than transwall failure.更多还原