Abstract: Aiming at the problems of complex working conditions, multiple external forces and great influence on the life of structural parts of agricultural machinery, this paper took the orchard working platform frame as the research object, compiled the accelerated load spectrum of the frame and analyzed the durability of the frame. The finite element analysis method was used to carry out mechanical analysis of the frame and select the key load measuring points. The multibody dynamics model of the orchard operation platform was established to collect the load spectrum of the corresponding measuring points. The accelerated load spectrum of different pseudodamage retention amounts was obtained by using the pseudodamage retention editing method. The influence of pseudo damage retention on the mass of accelerated load spectrum was analyzed. The effects of different editing schemes on the accuracy and efficiency of durability analysis were compared by frame durability simulation. The comparison results show that the pseudo damage retention is not less than 90% to ensure the quality of the accelerated load spectrum. The simulation results show that the minimum life course of the frame is about 65 000 km. According to the service condition of the orchard operating platform and the users service condition survey, it is known that the orchard operating platform travels about 8 100 km every year and the service life is 8 years. The frame meets the requirements. When the pseudo damage retention is 95%, it is the best preparation scheme, the time compression of the accelerated load spectrum is 55%, the error of the frame durability simulation analysis can be controlled within 5% and the simulation efficiency can be increased by 391%. This paper provides reference for improving the editing quality of the durability load of agricultural machinery parts.

Key words: orchard operation platform, frame, acceleration load spectrum, pseudodamage retention coding method, durability

摘要： 针对农用机械作业工况复杂、受多种外力、对结构件寿命影响较大等问题，以果园作业平台车架为研究对象，编制车架加速载荷谱，分析车架耐久性。采用有限元分析方法，对车架进行力学分析并选取关键载荷测点，建立果园作业平台多体动力学模型采集相应测点载荷谱，利用伪损伤保留编辑法获取不同伪损伤保留量的加速载荷谱，从压缩时间效率、伪损伤域、功率谱密度、穿级/雨流计数和统计值参数等方面对比，分析伪损伤保留量对加速载荷谱质量的影响。通过车架耐久性仿真对比不同编辑方案对耐久性分析精度和效率的影响。对比结果表明，伪损伤保留量不低于90%才能保证加速载荷谱的质量。仿真结果表明，车架最小寿命历程大约为65 000 km，根据果园作业平台使用条件和用户使用情况调查，了解果园作业平台每年大约行驶8 100 km，使用年限为8年，该车架满足要求。且伪损伤保留量为95%时为最佳编制方案，加速载荷谱时间压缩量为55%，车架耐久性仿真分析误差能控制在5%内且仿真效率提高391%，本文为提高农用机械部件耐久性载荷的编辑质量提供参考。

关键词: 果园作业平台, 车架, 加速载荷谱, 伪损伤保留编制法, 耐久性