圆弧形榫连结构低周疲劳试验设计与寿命预测

为了研究大涵道比涡轮风扇发动机宽弦风扇叶片中采用的圆弧形燕尾榫连结构的低循环疲劳寿命,设计了1种双榫头的低循环疲劳试件及夹具,该试件具有可以避免试件上打孔、所受载荷单一、节省试验时间等优点。利用通用软件ANSYS对试件及夹具进行了3维接触应力分析,得到了试件及夹具上的应力分布规律,证明了该试件设计的可行性与合理性。考虑多轴应力对寿命的影响,对试件进行了弹塑性分析,用4种方法预测了试件的疲劳寿命并与初步的试验结果进行了比较,给出了4种预测方法的相对误差。结果表明:Neuber法和等效应变法应用较方便且预测结果均在可接受范围内。

Low Cycle Fatigue Test Design and Life Prediction for Arc-dovetail Components

A new specimen and fixture of the low cycle fatigue test for the arc-dovetail components was devised. The arc-dovetail components were used in the fan blades of the high bypass ratio aircraft engine. Using the new specimen can avoid drilling holes on them and avoid the specimen working under single load; the application of the specimen can save the test time as well. The three-dimensional stress analysis of the specimen was analyzed by using the software ANSYS, distribution rule of the specimen and the fixture on the stress were received. The numerical simulation results indicate the design was feasible and reasonable. The elastic-plastic of the specimen was analyzed, and the multi-axial fatigue life was estimated using four methods. The estimated results were compared with the test results and the relative error was given. The results indicate that the Neuber method and the equivalent stain method are convenient and reasonable.