Measurement of Residual Stress in Titanium Alloy Wide-Chord Hollow Fan Blade Based on Multiple-Cut Contour Method

Hollow fan blades made of titanium alloy are widely used in turbofan engines, and the residual stress (RS) inside the blades directly affects the performance of the blades and even the engine. Therefore, it is crucial to measure and study the RS distribution of titanium alloy hollow fan blades. This paper aims to investigate the RS distribution on the cross-section of a wide-chord hollow fan blade made of Ti-6Al-4 V titanium alloy. The multiple-cut contour method is utilized to determine the RS. A theoretical model of the multiple-cut contour method for fan blades is established, and the specimen was cut three times, followed by contour measurement of the cut planes, data processing and elastic finite element analysis. The RS map of the three cut planes is finally presented. The normal RS on three cross-sections of the fan blade is uniformly distributed, ranging from -50 MPa to 50 MPa. The normal RS distribution at different positions for the hollow fan blade can be obtained by the proposed multiple-cut contour method. The findings of this research provide a comprehensive insight into the distribution of RS in wide-chord hollow fan blades made of Ti-6Al-4 V titanium alloy.