某空心风扇叶尖进气道封焊疲劳失效研究

针对某空心风扇叶片叶尖在高循环疲劳试验中异常失效的现象,应力分布测试和振动仿真分析表明应力集中部位与失效位置不符,断口分析结果表明裂纹萌生于叶尖的通气孔封焊部位,磨除进气道封焊层的叶片试验验证表明失效源于叶尖进气道焊接缺陷。基于失效机理分析及验证,确定失效源于加工环节焊接工艺选择不当且焊接控制不良,因此制定了更换封焊工艺为电子束焊和CT检测环节的改进措施。

Research on Hollow Fan Blade Tip Welding Failure in HCF Test

For the unexpected tip failure of hollow fan blade HCF test, the stress distribution test, vibration simulation and crack analysis were done. The test results indicate that the failure region is not the high stress region, and fracture anal-ysis indicates that the crack initiates from the welding area of the duct in the blade tip. Validation test on the blades without the tip welding shows that the failure is induced by the welding defect in the blade tip duct. Based on the fatigue analysis and test validation, the failure occurs by improper welding method selection and welding process control in the manu-facturing process. Consequently, the improved process is applying the EB welding in manufacturing and CT inspection.