Abstract: In order to improve the structural stiffness of the small sugar cane harvester and avoid the occurrence of resonance while satisfying the demand for light quantization, the topology optimization method is used to optimize the frame. Firstly, the threedimensional model and finite element model of the small sugar cane harvesting carrier were established. The accuracy of the finite element mode is verified by modal test. Secondly, the static analysis of the frame is carried out and perform topology optimization with the objectives of minimum compliance and maximum dynamic stiffness, respectively. After the screening of optimized models, the safety of the optimization structure is verified by static analysis. Finally, physical properties are processed according to the optimized model and dynamic performance testing. The results of the transfer function test and the vibration test were obtained. The firstorder frequency is increased by 0.1 Hz, the peak frequency is slightly improved, and the quality is reduced by 10.6%. The amplitude of each frequency segment is larger than that of the frame before optimization. The firstorder frequency optimized by the side support beam is reduced by 0.3 Hz, the quality is reduced by 21.77%, the peak frequency is slightly improved, and the amplitude under 1-3 Hz is slightly smaller than the original frame. The firstorder frequency of the plateshaped structure optimized by dynamics is 0.9 Hz. The indicators of the transfer function are reduced. The amplitudes of each frequency section are less than the frame before optimization, and the frame quality is reduced by 12%, which is fully reached. The lightweight and dynamic characteristics of the frame beam structure are realized. It is known from the modal verification test: The frame of the small sugarcane harvester is optimized by three objectives, and the frequencies of each frame avoid the frequency range of engine excitation and other main excitations.

Key words: small sugarcane harvester, frame, modal analysis, topology optimization

摘要： 为提高小型甘蔗收获机的结构刚度，避免共振的发生，同时满足轻量化的需求，对其车架进行多目标多水平拓扑优化。首先建立小型甘蔗收获机车架的三维模型与有限元模型，通过模态试验验证有限元模态的准确性。其次对车架进行静力学分析，并分别以最小柔度和最大动态刚度为目标进行拓扑优化，对优化的模型进行筛选后，再通过静力学分析校验优化结构的安全性。最后，根据优化后的模型加工出实物并进行动态性能测试。通过传递函数测试与振动试验的结果可得：以静力学为目标优化的车架，第一阶频率提高0.1 Hz、峰值频率得到略微改善，并且质量降低10.6%，各频率段的振幅均大于优化前的车架；以侧向支承梁优化的车架，第一阶频率降低0.3 Hz，质量降低21.77%，峰值频率得到轻微改善，1~3 Hz下的振幅略小于原车架；而以动力学为目标优化的车架，第一阶频率提高0.9 Hz，传递函数各项指标均降低，各频率段的振幅均小于优化前的车架，车架质量减少12%，充分达到预期目标，实现车架板梁结构的轻量化和动态特性提升。由验证模态试验得知：三种方式优化后的车架，各阶频率均避开发动机激励以及其他主要激励的频率范围。

关键词: 小型甘蔗收获机, 车架, 模态分析, 拓扑优化