基于安全寿命法的高压涡轮盘低循环疲劳寿命试验

基于英军标Defence Standard 00971对盘类零件的安全性要求,采用安全寿命法对某型发动机高压涡轮盘的低循环疲劳寿命试验进行了研究.通过有限元法对发动机工作条件下的高压涡轮盘进行了应力分析,考虑了温度场对应力分布的影响,按照Defence Standard 00971的要求确定了高压涡轮盘的关键部位及其标准循环,制定了高压涡轮盘低循环疲劳寿命试验方案,给出了基于试验结果确定高压涡轮盘安全寿命的方法.分析表明:中心孔和螺栓孔的应力系数分别为1.0和1.017,均在合理范围内;提高高压涡轮盘转速同时截短涡轮叶片的试验方法能有效模拟热应力对寿命的影响,对高压涡轮盘低循环疲劳寿命试验具有重要指导意义.

Low cycle fatigue life test of high pressure turbine disk based on safe life procedure

The low cycle fatigue life test of high pressure turbine disk of an engine was studied by using safe life procedure based on Britain military standard Defence Standard 00971 safety requirements for disks. The finite element method was used for analyzing the stress field of high pressure turbine disk of engine under working conditions, and the effect of temperature field on stress distribution was considered. The critical position and reference cycle of high pressure turbine disk were determined according to Defence Standard 00971; then the test plan of low cycle fatigue life of high pressure turbine disk was formed, and the safe life assessment method of high pressure turbine disk based on test results was determined finally. The analysis shows that the stress factors of hub and bolt-hole are 1.0 and 1.017 respectively, which are within a reasonable scale; the test method of increasing rotation speed and cutting turbine blade simultaneously can simulate the effect of thermal stress on life effectively, giving important guidelines for low cycle fatigue life test of high pressure turbine disk.