航空发动机涡轮盘榫齿裂纹故障研究

B型机由 A型机改型而成 ,大批服役期中的 A型机存在着大量 级盘 (简称为盘 )第一榫齿裂纹与掉块故障。其轻者 ,裂纹超过标准后报废 ;重者 ,榫齿掉块 ,打伤其它零件 ,甚至叶片飞出 (简称脱榫 )。经过故障件金相检查 ,断口分析 ,其裂纹性质属机械疲劳。在疲劳损伤中 ,叶片类零件主要是高循环疲劳。为排除 B型机盘和叶片榫齿间连接的故障 ,我们研究了在飞行与试车台上 A、 B型机 级涡轮叶片 (简称为叶片 )的振动情况。一、试验装置用等离子喷涂方法将高温电阻丝应变片敷设在被测的叶片叶身测点上 ,再用 1Cr18Ni9Ti薄片将引线固定在盘后端…

A RESEARCH ON CRACKED FAILURES OF FIR-TREE SERRATION IN AEROENGINE TURBINE DISC

A lot of cracked failures of fir-tree serration accurred in the second stage turbine disc of a large numbers of certain types aeroengines in service.The characte of these cracks belongs to mechanical fatigue.In order to find out the cause for the cracked failure,the vibrating stresses of the second stage turbine blades on test bench and their vibrating strains in flight tests have been measured in the conditions of high temperature and high rotational speed.The measured data indicate that several resonance zones really exist in the second stage turbine blades of type A and B engines.Some methods for elimination of the cracked failures of fir-tree serration in the turbine disc are provided.According to the experiece in service,a modification of type B engine hase eliminated the cracked failures of fir-tree serration of turbine disc in its service life.