考虑局部应力效应的轮盘子午面破裂转速预测

平均应力法用于航空发动机轮盘破裂转速预测时结果一般偏大，对于带螺栓孔的轮盘破裂转速预测误差更大。考虑局部应力效应对平均应力法进行修正，引入修正因子来表征轮盘子午面平均周向应力和危险部位局部应力对轮盘破裂转速的加权影响。通过开展典型轮盘材料GH4169的光滑试样和缺口试样拉伸试验，并开展了两件模拟盘破裂转速测量试验，得到修正因子与缺口强度比的关系，然后同时采用这两种方法对某涡轮盘的破裂转速进行了预测，并开展了验证试验。试验结果表明:平均应力法预测结果偏大，误差达到了9.4%，而考虑局部应力修正后，预测值仅略低于试验值，误差仅2.67%。考虑局部应力效应的轮盘子午面破裂转速预测方法简单可靠，具有较高的工程实用价值。 

Prediction of hoop mode burst speed of disk considering local stress effect

Prediction result of burst speed of a aeroengine disk is usually slight larger than testing result when using the average stress method. The error tends to be much larger especially for the disk with a bolt hole. The average stress method was modified taking consideration of the effect of local stress.A correction factor was implanted to distinguish weight effect of the average hoop stress from that of the local stress of critical position at disk burst speed. Tensile test of standard cylinder and notched specimens of GH4169 and burst speed measurement test of two simulated disks were carried out. Notch strength ratio related to correction factor was calculated. Then the relationship between correction factor and notch strength ratio was obtained. Burst speed of a disk was predicted using these two methods and the burst speed measurement test was conducted. It concluded that the predicted result was larger than test data when using the average stress method with the error of 9.4%. When local stress was taken into consideration, the result was closely approximated to test data with the error of 2.67%. The prediction method of hoop mode burst speed of a disk considering local stress effect was of remarkable engineering practical worth value to its'' simple formality and the reliable results.