摘要
【目的】对某型号起重机主梁进行疲劳分析,评估其疲劳寿命,并探索有效的结构强化技术,以提高主梁的疲劳性能和使用寿命。【方法】首先,采用有限元分析和疲劳寿命预测方法对主梁进行分析;其次,应用S-N曲线和Miner线性累积损伤理论建立疲劳寿命预测模型;再次,通过加劲肋优化设计、焊接工艺改进和材料选择等方法实施结构强化;最后,使用一级二阶矩法和蒙特卡罗模拟进行结构可靠性验证。【结果】研究发现主梁下翼缘与腹板连接处存在疲劳裂纹隐患。通过结构强化,该处应力从255 MPa降至175 MPa;主梁整体疲劳寿命从20.5 a延长到29.1 a,15 a设计寿命的可靠度从0.92提升至0.9875。【结论】采用Q355B钢并结合优化设计和改进工艺,可显著提高起重机主梁的疲劳性能和可靠性。建立的疲劳寿命预测模型为类似结构的设计与优化提供了参考。未来研究方向包括多场耦合疲劳分析和全寿命周期监测与评估。
[Purposes]This study aims to conduct fatigue analysis on a specific type of crane main beam,assess its fatigue life,and explore effective structural strengthening techniques to improve the beam's fatigue performance and service life.[Methods]Firstly,the finite element analysis and fatigue life prediction methods were employed to analyze the main beam;secondly,a fatigue life prediction model was established using S-N curves and Miner's linear cumulative damage theory;thirdly,structural strengthening was implemented through optimized stiffener design,improved welding techniques,and material selection;finally,first-order second-moment method and Monte Carlo simulation were used for structural reliability verification.[Findings]The study identified fatigue crack risks at the junction of the lower flange and web of the main beam.Through structural strengthening,the stress at this location was reduced from 255 MPa to 175 MPa.The overall fatigue life of the main beam increased from 20.5 years to 29.1 years,and the reliability for a 15-year design life improved from 0.92 to 0.9875.[Conclusions]The use of Q355B steel,combined with optimized design and improved processes,can significantly enhance the fatigue performance and reliability of crane main beams.The established fatigue life prediction model provides a reference for the design and optimization of similar structures.Future research directions include multifield coupled fatigue analysis and full life cycle monitoring and assessment.
作者
乾红伦
付建阳
郭利娟
牛鹏飞
QIAN Honglun;FU Jianyang;GUO Lijuan;NIU Pengfei(Henan Hengyuan Hengshan Industry Co.,Ltd.,Xinxiang 453400,China)
出处
《河南科技》
2025年第2期57-61,共5页
Henan Science and Technology
关键词
起重机主梁
疲劳分析
结构强化
有限元分析
疲劳寿命预测
crane main beam
fatigue analysis
structure strengthening
finite element analysis
fatigue life prediction
