TC17 合金弯曲振动超高周疲劳试验

针对航空发动机压气机叶片用TC17合金的超高周疲劳性能数据需求,自主设计超高频板材试样并在电动振动台上开展弯曲振动疲劳测试,获取了109循环数范围内的超高周疲劳S-N曲线,并通过升降法得到了该合金109循环数对应的疲劳极限强度,在实际测试过程中有效激振频率达到1756 Hz左右。此外,与相同材料的常规疲劳试验结果进行了对比分析。结果表明:超高频弯曲振动疲劳试验结果与常规疲劳试验结果的变化趋势保持一致,尤其是在超高周寿命区间的测试结果的接近程度较高;超高频弯曲振动试验方法在提高测试效率的同时保证了结果的可靠性。

Vibration Bending Fatigue Test of TC17 Ti-alloy in the Very-High-Cycle Regime

In order to meet the very-high-cycle fatigue(VHCF)data requirement of TC17 which was a Ti-alloy used in aeroengine compressor blade,a vibration bending fatigue testing method based on a designed ultra high frequency sheet specimen and electro-shaker was proposed.The S-N curve in the VHCF regime up to 109 cycles was obtained by the present testing method and the fatigue limit at 109 cycles was obtained by the up-down method.The actual testing frequency of the designed specimen can get up to about 1756 Hz.Further?more,the comparison of the present testing results and the traditional fatigue testing results for the same materials were conducted.The re?sults show a good consistency between the present test and the traditional fatigue testing results,especially in the VHCF regime.Thus the pro?posed ultra-high frequency vibration-based fatigue test shows a balance of high efficiency and similarity with the conventional testing results.