基于模态规划法的履带拖拉机车架振动分析与优化

为优化拖拉机车架振动参数,改善驾驶舒适性,本文基于模态规划法对履带拖拉机车架进行振动分析与优化。现场测试了履带拖拉机田间行驶工况下车架X、Y、Z方向的时域振动参数,采用傅里叶分析法获取振动的线性自功率谱参数,数据表明加速度峰值对应频率为8.125 Hz、21.25 Hz、42.5 Hz和85.625 Hz。建立车架有限元模型并进行模态求解,第2阶固有频率23.98 Hz、第4阶固有频率85.00 Hz与振动激励峰值频率之间的差值均小于3 Hz。采用模态规划法和响应面法优化车架模态参数,获取了各个因素对目标参数的影响规律,当两根支撑梁之间间距、支撑梁壁厚、支撑梁边长分别为149.90 mm, 5.01 mm和65.00 mm时,第2阶和第4阶模态频率最优。通过有限元仿真对最优解进行验证,仿真结果表明,第2阶固有频率和第4阶固有频率分别为48.53 Hz和89.97 Hz,对应的误差率分别是1.99%和1.03%,具有较好的优化效果。本文的研究方法和结论可推广至其他农业机械的振动优化分析。

Vibration analysis and optimization of tracked tractor frame based on modal programming method

Aiming at optimizing the vibration characteristics of the tractor frame and improve driving comfort, vibration of the tractor frame based on the modal programming method was analyzed and optimized in this paper. The time domain vibration parameters in the X, Y, and Z directions of the tractor frame were tested, and the linear self power spectrum parameters were calculated by using the Fourier analysis method. Acceleration peak values occurred at 8.125 Hz, 21.25 Hz, 42.5 Hz, and 85.625 Hz. The finite element model was established and modal parameters were solved. The results show that the difference between the second order natural frequency, the fourth order natural frequency, and the vibration excitation peak frequency was less than 3 Hz. The frame modal parameters were optimized based on modal programming method and response surface method. The influence law of each factor on the target parameters was determined. The second and fourth order modal frequencies were optimal when factors A, B, and C were 14990 mm, 5.01 mm, and 65.00 mm, respectively. The simulation results showed that the optimizing natural frequencies of second and fourth order were 48.53 Hz and 89.97 Hz and the corresponding error rates were 1.99% and 1.03%. The analysis methods and conclusions in this paper may be extended to the vibration optimization of other agricultural machinery.