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某烟气轮机涡轮盘发生了盘缘断裂掉块事故,某航空发动机Ⅰ级涡轮盘也大量发生槽底裂纹的故障。我们对这两个盘的盘体和槽底部分用轴对称和平面8节点等参元有限元法对温度场(包括瞬态温度场)与应力场进行了计算,从而对涡轮盘在不同工作状态下的应力分布及故障原因进行了分析。本文着重阐述冷却条件对于涡轮应力分布是十分重要的,同时,不应忽视轮缘的应力水平,在某特定工作状态下,轮缘的应力值可能远远超过轮心,而且循环的应力幅值也很大,且由于载荷与几何形状的复杂性,在轮缘与榫齿的过渡段上出现较大的应力集中,往往成为裂纹源区;本文最后分析了轮缘残余应力形成及对槽底径向裂纹的生成与扩展的影响。
A gas turbine turbine disk rupture occurred off the edge of a block accident, a certain level of aeroengine turbine disk groove crack occurred in a large number of failures. We calculated the temperature field (including the transient temperature field) and the stress field using the isoparametric finite element method of axisymmetric and planar 8-node isolators for the plate and groove bottom of the two disks, State of the stress distribution and causes of failure were analyzed. This paper focuses on the cooling conditions for the turbine stress distribution is very important, at the same time, should not ignore the stress level of the rim, under certain operating conditions, the flange stress may far exceed the wheel center, and the cyclic stress amplitude But also due to the complexity of the load and geometry, a large stress concentration appears on the transition section between the wheel rim and the tenon and often becomes the source region of the crack. At the end of this paper, the formation of the residual stress in the rim and the effect on the groove bottom The Influence of Radial Crack Formation and Expansion.