钛铝涡轮轴与K418合金轴套过盈配合内应力分析

通过有限元ABAQUS软件对钛铝涡轮轴与K418合金轴套的过盈配合进行了详细研究,分别从过盈量、连接件几何结构和装配长度等因素入手,分析了压装过程中应力的变化情况,指出应力最大的位置,从理论上提出降低应力和提高寿命的措施。比较钛铝涡轮轴与K418合金轴套不同过盈量下及不同接触长度下过盈配合装配的应力分布结果,表明过盈量是影响装配应力的主要因素,得出较合理的过盈量应在0.15 mm左右,装配接触长度对装配应力也有一定影响。通过不同过渡圆角的模拟计算发现过渡圆角的大小对应力的影响较大,与压装过程中出现的应力峰值有直接的关系。所以在设计时可以采取在合适的范围内增大过渡圆角或添加去应力槽的方式减小应力集中现象,从而降低装配过程中出现的应力峰值,减少对涡轮轴材料的损伤。

Internal Stress Analysis of Interference Fittings of TiAl Turbine Shaft and K418 Alloy Sleeve

Interference fittings of TiAl turbine shaft and K418 alloy sleeve were studied by the software of finite element method ABAQUS. The variation of stresses in assembling process were simulated and calculated by different fit tolerances, geometry and contact lengths. The danger situation of the shaft and sleeve was found by analyzing the stress distribution, and the measures were put forward to decrease contact stress and improve performance life. By comparison of stress distribution results of the different fit tolerances and different contact length, it was shown that fit tolerance had a main effect on the contact stress, and fit tolerance of 0. 15 mm was the optimal choose. And the contact lengths had some effect on the contact stress too. Simulated results at different transitional arc radius showed that it affected contact stress heavily, and it was concerned maximum contaet stress in the assembling process. So these effects were considered in design process to reduce the material damage, stress concentration and maximum contact stress were reduced by increasing transitional arc radius or add stress relieving slot.