in-situ test device and method for high-low cycle composite fatigue performance of material

The invention relates to an in-situ test device and method for high-low cycle composite fatigue performance of a material, and belongs to the field of precision scientific instruments. An instrument supporting frame in the device is used for achieving stable supporting and precise positioning of other functional modules. The low-frequency load loading module is driven by servo hydraulic pressure and is used for loading a low-frequency fatigue load of 0.001-50 Hz to the test sample; the high-frequency load loading module is driven by electromagnetic resonance and is used for loading a high-frequency fatigue load of 5-5000 Hz for the test sample, and the high-frequency load loading module and the high-frequency fatigue load loading module can be used independently and can also be matched with each other to construct a high-low-cycle composite fatigue load together; and the in-situ monitoring module is used for realizing high-resolution visual dynamic monitoring on the fatigue crack initiation, expansion and fra