• 论文 •

### 木材裂纹尖端应力场的有限元分析和开裂方向预测

1. 1.安徽农业大学林学与园林学院 合肥 230036；2.合肥工业大学土木工程学院 合肥 230009
• 收稿日期:2009-03-13 修回日期:2010-06-30 出版日期:2010-10-25 发布日期:2010-10-25

### Analysis of Stress Field Near Crack Tip Using Finite Element Method and Prediction of Cracking Direction for Wood Sample with Crack

Shao Zhuoping<sup>1</sup>;Tong Yongyao<sup>2</sup>;Sheng Hongyu<sup>2</sup>;Niu Zhongrong<sup>2</sup>;Dong Honggan<sup>1</sup>

1. 1 <i>School of Forestry and Landscape Architecture;Anhui Agricultural University Hefei</i> 230036;2 <i>School of Civil Engineering;Hefei University of Technology Hefei</i> 230009
• Received:2009-03-13 Revised:2010-06-30 Online:2010-10-25 Published:2010-10-25

Abstract:

Taking SEB samples of spruce (<i>Picea asperata</i>) for instance, the finite element software of ABAQUS was used to analyze the stress field of the samples, when the obliquity between the wood crack and the grain of wood were 90°, 60°, 30°, 0° respectively, “tangential normal stress intensity factor ratio criterion” was applied to predict the direction of the crack.The results showed the direction of the maximum Mises stress of four samples was along the grain of the wood when drawing a radial plane centered around the crack tip. It is also shown that the ratio of the tensile stress perpendicular to the crack (σ<sub>Y</sub>) to the tensile stress parallel to the crack (<i>σ<sub>X</sub></i>) is approximately a constant within 1～5 in a large area around crack tip but except the singular point. No matter what is the angle of the initial crack to the grain of wood, the tangential normal stress intensity factor ratio (R) of the crack tip over the direction of the grain was the largest. Therefore, the initial crack direction along the grain had been verified either by theoretical prediction or by experiment. The role of toughening of low-interfacial strength between wood cells has been discussed.