一种航空发动机测量耙构件寿命曲线的确定方法及试验验证

测量耙振动加速考核使用寿命时,需根据其结构疲劳关系选择合适的振动量级,直接使用测量耙真实构件进行疲劳试验获取疲劳曲线需大量的构件样本,从而导致试验周期较长,试验经费庞大。本文针对测量耙常用材料1Cr18Ni9Ti开展拉伸试验,采用经验规律预估方法获得材料的S-N曲线,基于材料S-N曲线及小子样测量耙模拟试件疲劳试验数据修正,提出了一种基于材料拉伸试验数据的构件S-N曲线预测方法,并开展了模拟构件的疲劳试验,试验结果验证了该方法的可行性及合理性,确定的测量耙构件疲劳曲线可用于后续测量耙加速考核试验中振动量级的选择,该方法也可进一步扩展到工程中预估复杂结构件的载荷-寿命关系。

A Method for Determining the Fatigue Curve of Rake Components in Aeroengine and Test Verification

The service life of rake is assessed by the vibration acceleration method, it is necessary to select the appropriate vibration level according to the structural fatigue relationship.It requires a large number of component samples to directly use the real components of the rake to perform the fatigue test to obtain fatigue curve, which leads to a long test period and a large test cost. In this paper, the tensile test of 1Cr18Ni9Ti was carried out, and the materials S-N curve was obtained by using the empirical law prediction method. Based on the materials S-N curve and the small sample rake simulation specimen fatigue test data correction, a prediction method of the components S-N curve based on the material tensile test data was proposed. The feasibility and rationality of the proposed method were verified by the fatigue tests of components. The determined fatigue curve of rake in aero-engine can be used for the selection of vibration magnitude in the subsequent acceleration test. The proposed method can be further extended to predict the load-life relationship of complex structural components in engineering.