针对某型燃气轮机支承环在试验过程中发生断裂、掉块故障，分别进行了强度计算、振动模态分析、低循环疲劳寿命分析以及断口分析。综合分析结果表明：支承环故障属于高低周复合疲劳；焊缝和螺纹处应力集中导致应力过大而开裂；采取把周向焊缝取消，将月牙板和罩壳一体设计及降低应力集中等措施，排除故障。

The strength calculation,vibration mode analysis,low cycle fatigue analysis and fracture analysis were carried out respectively in view of the failure of block loss of certain gas turbine supporting ring during the test.The comprehensive analysis results show that the turbine supporting ring fracture failure is caused by high and low cycle composite fatigue.Stress concentration in welds and threads leads to excessive stress cracking.The fault can be eliminated by canceling the circumferential weld,integrating the design of the cover enclosure and crescentshaped plate and reducing the stress concentration.

TH133.1

国家科技重大专项（2017-V-0003）