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针对收割机割台框架容易产生疲劳现象,对割台框架进行了疲劳寿命分析。建立了割台框架有限元模型,求解出割台框架模态频率与振型;测取割台框架平整路面与田间路面两种典型路面不同工况下的载荷,根据雨流计数法编制成载荷谱;结合材料属性进行了疲劳寿命计算。研究结果表明:割台框架的疲劳寿命大小主要与应力幅值有关,应力幅值越大疲劳损伤值越大疲劳寿命越低;割台框架寿命约为2545h,低于收获机械一般疲劳寿命水平;针对疲劳强度薄弱部位后壁上横梁采用局部加厚4mm,经计算改进后疲劳寿命约为2.196×10~4 h,疲劳强度符合要求。
In view of the fatigue of the header frame of the harvester, the fatigue life of the header frame is analyzed. The finite element model of the header frame was established and the modal frequencies and modes of the header frame were solved. The load of the two typical pavements on the flat road surface and the field pavement of the header frame was measured. According to the method of rain flow counting, Spectrum; fatigue life calculation based on material properties. The results show that the fatigue life of the header frame is mainly related to the stress amplitude. The larger the stress amplitude is, the greater the fatigue damage is and the lower the fatigue life is. The life span of the header frame is about 2545 h which is lower than the general fatigue life of the harvesting machinery. For the fatigue strength of the weak parts of the rear wall of the local thickening of the beam 4mm, calculated by the improved fatigue life of about 2.196 × 10 ~ 4h, the fatigue strength to meet the requirements.