中文摘要：

齿根过渡圆角对齿根应力有着重要影响,而齿根应力是齿根疲劳裂纹扩展的重要影响因素,因此,研究齿根过渡圆角半径对齿根裂纹扩展的影响十分必要。建立3种不同过渡圆角半径的直齿轮,假设齿根初始裂纹在相同位置,初始裂纹长度一致,基于ABAQUS软件研究齿根裂纹扩展规律。结果表明,不同过渡圆角半径下的齿根裂纹扩展总体趋势一致,但扩展前期过渡圆角半径越大,裂纹越向深入齿轮轮缘方向扩展,扩展后期过渡圆角半径越大,裂纹越往齿顶方向扩展。过渡圆角半径对齿轮临界裂纹长度影响较小。相同裂纹长度下,过渡圆角半径越大,裂纹尖端Mises应力越小,裂纹扩展速率越小,齿轮的裂纹剩余寿命越长。

英文摘要：

The transition arc radius has an important influence on the root stress and root stress is an im- portant influencing factor on the tooth root fatigue crack propagation, so that it is necessary to study the influ- ence of transition arc radius on the tooth root crack propagation. Three kinds of spur gears with different transi- tion arc radius are established and assume the root initial crack with same length in the same position, researc- hing the tooth root crack propagation based on ABAQUS. The results indicate that, the root cracks with different transition arc radius have the same propagation trend, but larger transition are radius with more extended to the deep crack direction gear rim in the early stage, larger transition arc radius with more extends to the top of the tooth in the later period. The transition radius has little influence on the critical crack length. Under the same crack length, the larger the transition radius with the smaller the Mises stress at the crack tip and the smaller the crack growth rate, the gear has the longer residual life.