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Research on Mechanisms of Crack Initiation of Rear Axle for a Passenger Car During Accelerated Life Testing in a Proving Ground

Year: 2025
Type: preprint
Abstract: To investigate the fracture crack in the rear axle of a certain passenger car during accelerated life testing, a comparative testing analysis was conducted on this car after replacing its new rear axle and on a comparative car. Strain on the rear axle, vibration acceleration, and vehicle speed signal were measured for both cars. Using the cyclic stress-strain hysteresis loop equation and Neuber's Rule, the nominal strain histories obtained from tests were converted to local stress-strain responses at the fracture crack locations. Subsequently, the fatigue damage to the rear axles of both the target car and comparative car was calculated based on Morrow's mean stress correction model and Miner's linear cumulative damage rule. The frequency sweeping of vibration mode was performed on the car bodies and rear axles of both cars using electromagnetic exciters to establish the correlation between the vibration frequency of rear axle, the excitation frequency of PG durability road, and the body vibration frequency. The calculations of fatigue damage and the frequency sweep testing results indicated that the accumulated damage to the rear axle of the target car was primarily concentrated on the washboard road of the PG. On this road surface, the standard deviation of rear axle strain and the RMS value of acceleration were higher than those observed in the comparative car. At a test speed of 65 km/h, the excitation frequency of forced vibration caused by the washboard road was 24.1 Hz, which was close to the natural frequency of the vibration modes of target car's rear axle, leading to resonance. This resulted in the rear axle experiencing significant amplitude alternating stress, thereby causing the crack initiation of vibration fatigue.
DOI: 10.20944/preprints202504.0970.v1
Institution: Suqian University
Language: English
Open Access status: green
OpenAlex ID: W4409400315
Cites: 4
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Related to: 10