大马力拖拉机典型行驶工况轮耦合试验方法研究

Coupled Wheel Testing Method under Typical Driving Conditions of High-horsepower Tractors

摘要:

借助实验室台架实现拖拉机实际作业工况下的耐久性试验模拟，对拖拉机可靠性提升具有重要意义。本文借助四立柱轮耦合试验台，开展拖拉机整机耐久性试验方法研究。构建了载荷采集系统，获取了拖拉机实际作业工况载荷数据，采用时域损伤保留识别方法、基于时频分析的累积功率谱密度识别方法和基于小波变换的包络线识别方法进行加速编辑研究，并通过轮耦合台架试验进行加速效果评价。结果表明，在本文应用场景及迭代方法下，基于时频分析的累积功率谱密度识别方法在信号压缩比例方面表现最优，缩减比例达36.37%。基于原始信号及上述3种加速方法，通过加速编辑与迭代处理，获得轮耦合试验台驱动载荷谱，加载效果表明，以底盘、驾驶室为试验目标时均能满足对特定目标测点损伤复现的倾向性，同一试验目标、不同加速识别方法下，基于时频分析的累积功率谱密度识别法在底盘损伤复现方面一致性更佳，时域损伤保留识别法在驾驶室损伤复现方面一致性更佳。

Abstract:

Tractors are the most widely used power machinery in agricultural production. Conducting durability simulations of tractors under real-world operating conditions through laboratory test benches is of great significance for improving their reliability. A four-column wheel coupling test bench was utilized to explore the whole-machine durability testing methodology for tractors. An operational load acquisition system was established to collect load data under actual working conditions. Accelerated life testing was conducted by using three different identification methods: the time-domain damage retention identification method, the time-frequency analysis-based cumulative power spectral density identification method, and the wavelet transform-based envelope identification method. The effectiveness of these acceleration methods was validated through wheel coupling bench testing. The results indicated that, within the application scenarios and iterative approaches adopted, the time-frequency analysis-based cumulative power spectral density identification method demonstrated superior performance in signal compression, achieving a reduction ratio of 36.37%. The drive load spectra for the wheel coupling test bench were iteratively derived from both the original signal and the three accelerated signals. The loading results demonstrated that when the chassis and cab were selected as test targets, the damage reproduction tendency at designated measurement points was effectively achieved. Under the same test conditions but with different acceleration identification methods, the time-frequency analysis-based cumulative power spectral density identification method showed superior consistency in reproducing chassis damage, while the time-domain damage retention identification method performed better in replicating cab damage.