带锯条的裂纹与断裂

CRACK AND FRACTURE OF BANDSAW BLADE

根据弹性力学平面应力问题有限元法基本理论,对带锯条锯齿上不同长度裂纹尖端应力进行了计算,在此基础上,研究与分析了带锯条的裂纹对断裂强度的影响。结果表明,循环加载是裂纹产生、延伸及锯身断裂的主要原因。在裂纹对断裂强度的影响的多种因素中,裂纹长度的影响尤为重要。裂纹尖端应力随裂纹长度增加而增大,此时断裂强度下降,锯身允许的循环载荷次数减少,使用寿命缩短。

In this paper, the point stress of different length oraoks in bandsaw teeth is calcuiatcd, according to the basic theory of plane stress problem of finite element method. On the base of it the effect of cracks of bandsaw blade on fracture strength has been studied and analysed. The result showed that circle loading is the main reason of generation of crack, strength and fracturt of blade. The effect of the length of crack is the most imporant. The point stress of crack increases with the length of crack increasing, while the fracture strength descends, the allowed number of circle loading reduces and the time of using shortens.