【作者】 顾浩；

【导师】 朱如鹏；

【作者基本信息】 南京航空航天大学 ， 机械设计及理论， 2007， 硕士

【摘要】 齿轮传动是机械传动中最主要的一种传动型式,在工业、农业、国防中有广泛的运用。但齿轮在传动过程中经常发生齿根断裂,严重影响了齿轮的使用。本文研究了渐开线齿轮齿根裂纹的二维断裂力学特性,为进一步研究齿轮断裂仿真和安全设计打下理论基础。在渐开线齿轮齿根裂纹建模过程中,主要采用APDL参数化语言和Matlab软件混合建模。根据渐开线直角坐标方程和齿根过渡曲线方程,在Matlab中生成一系列关键点坐标值,保存这些点的坐标值为数据文件,再用ANSYS中的APDL参数化语言调用这个数据文件,生成齿轮模型,建立齿轮模型后,再完成根部裂纹模型的建立。在应力强度因子的计算过程中,从线弹性断裂力学角度出发,应用ANSYS软件计算裂纹尖端应力强度因子。研究了不同裂纹长度下,应力强度因子的变化趋势,还研究了齿轮结构参数,对齿根裂纹尖端应力强度因子的影响。在研究齿根裂纹扩展过程中,介绍了两种裂纹扩展方向的理论计算方法。即能量法和最大周向应力法。根据最大周向应力法,计算了裂纹失稳后的扩展角,并在ANSYS中分步模拟了裂纹的扩展趋势,同时研究了齿轮结构参数对裂纹扩展趋势的影响。更多还原

【Abstract】 Gear is an important transmission component. Gear tooth root fracture frequently happens in the course of transmission, which has great effect on use of gear. This paper studies the two-dimensional fracture properties of involute gear tooth root crack which is the theoretical foundation of the simulation of gear tooth fracture and damage tolerance design.First, the modeling of the gear tooth with crack is discussed by using ANSYS parametric design language (APDL) and Matlab. According to the equations of the involute tooth profile and tooth root fillet, a series of key point coordinates are generated using Matlab and stored in text file. Then, using the APDL the gear model is generated. Finally the gear model with tooth roots crack is completed.Secondly, according to the linear elastic fracture mechanics method, the crack tip stress intensity factor is calculated by ANSYS. The variation of stress intensity factor with crack length and gear structural parameters is studied.Finally, the crack propagation direction is discussed by maximum circumferential stress method and the energy release rate method. According to the maximum circumferential stress method, the crack angle could be computed and crack propagation is simulated by ANSYS.更多还原