Fatigue life prediction for tower cranes under moving load

For the tower crane, the luffing trolley and cargoes are equivalent to concentrated force. This study established a moving load model. The transient dynamic analysis method was used to carry out dynamic simulation, analyze and obtain the vibration characteristics of the boom under luffing and lifting, and calculate the fatigue life of the key components of the boom based on the S-N curve. The analysis results showed that the greater the luffing speed, the greater the arm end vibration amplitude. The lifting speed has influence on the amplitude and frequency of vibration. Under the worst working conditions, the minimum service life of the top chord 638 of the most dangerous component was 17.96 years, which can meet the requirements of the safety regulations for tower cranes. At the same time, the damage degree of the dangerous component during luffing was greater than that during lifting.