Fatigue reliability evaluation of heavy-haul locomotive car body underframe based on measured strain and virtual strain

Fatigue reliability evaluation of heavy-haul locomotive car body underframe was conducted based on measured strain and virtual strain. The coupler load was calibrated by combining bench test and linear fitting. Acceleration responses and dynamic strains of key positions were measured. The load–strain transfer coefficients of the car body were obtained by finite element analysis (FEA). The virtual strain was calculated by combining the obtained coefficients with the measured coupler load history and acceleration history. The frequency spectrum of the measured strain and the virtual strain was compared. The fatigue damage and fatigue life of measured strain and virtual strain under reliabilities of 95% and 97.7% were compared.