Force-displacement hybrid control motorcycle frame fatigue test method

The invention discloses a force-displacement hybrid control motorcycle frame fatigue test method which comprises the following steps that 1), finite element analysis is performed on a motorcycle frame, and a road load spectrum during actual running is acquired in a durability test road; 2), the road load spectrum is subjected to analysis processing and validity check, and a concentrated load spectrum is obtained; 3), a motorcycle frame assembly is mounted on a test system, and a frequency response function and a coherence function are calculated; 4), a frequency response function for calculating an excitation driving signal is constructed; and 5), a corresponding strain signal and an acceleration signal are extracted from the concentrated load spectrum, and driving signals of two vibration exciters are calculated. According to the test method, a force-displacement hybrid control mode is adopted, so that an actual stress situation of the motorcycle frame is completely matched; decoupling of a multi-axial and multi-excitation test is achieved; very high simulation precision can be obtained; and simulation points are found out by coherence analysis, and the load spectrum is concentrated, so that a test period is shortened greatly.