Multi-blade vibration fatigue strength test method

The invention discloses a multi-blade vibration fatigue strength test method, which comprises the following steps of: installing a plurality of test blades pasted with strain gauges in a special clamp device, carrying out stress distribution and blade tip amplitude calibration by loading vibration loads step by step, determining an S-N curve of the blades through a sine-excited vibration fatigue strength test, and determining the fatigue strength of the blades according to the S-N curve. According to the method, narrow-band random parameters are obtained through calculation, narrow-band random excitation is carried out, a multi-blade fatigue strength test is completed through the method, fatigue strength examination is completed on multiple blades at the same time, the applicable test method is provided, the multi-blade vibration fatigue strength test is achieved, and a test analysis result can be directly and accurately obtained. The fatigue performance of the multiple blades can be truly examined and evalua