装载机减振分析及动力总成悬置系统优化设计

发布时间：2018-01-04 05:28

本文关键词：装载机减振分析及动力总成悬置系统优化设计　出处：《山东大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着技术水平的提高,工程机械的作业能力不再是评判机械设备的唯一指标,其振动与噪声水平成为能否被市场认可的首要条件。动力总成作为车辆主要的振动激励源,通过悬置安装在车架上,其工作过程中的不平衡惯性力及转矩波动通过车架传递到驾驶室,对整车的舒适性影响较大。设计合理的动力总成悬置系统可以有效减少振动向车架及驾驶室的传递,还可以避免零部件因振动过大带来的过早损坏问题。本文针对某型号装载机定置状态下振动过大的问题进行了研究,通过试验测试发现,动力总成悬置系统在多个转速下产生了共振,且悬置隔振率不高,需要对动力总成悬置系统进行优化设计。通过相关文献的阅读,掌握了动力总成悬置系统的设计思路及隔振分析方法,运用拉格朗日法建立了动力总成悬置系统的六自由度模型。根据此动力学模型,分析得到动力总成悬置系统固有频率特性、能量解耦率、动态响应特性的计算方法。试验获取了动力总成悬置系统的基本参数,包括：动力总成的质心位置、转动惯量及惯性积,悬置的安装位置、安装角度及刚度值。根据动力总成悬置系统动力学模型,基于MATLAB软件编制了悬置系统模态计算程序,并与多体动力学软件ADAMS进行了对比,计算结果准确可靠,分析得出动力总成悬置系统优化设计的方向。以悬置安装参数为优化变量,六自由度能量解耦率及悬置处动反力幅值最小为目标函数,建立了动力总成悬置系统优化模型。在优化模型基础上,基于MATLAB/GUI平台编制了动力总成悬置系统优化设计软件,优化算法采用序列二次规划算法和遗传算法,可以实现悬置系统的模态计算、优化设计以及动态响应分析三方面功能。采用所编制的优化软件,对该型号动力总成悬置系统进行了优化设计。对比两种优化算法得到的解耦方案,遗传算法作为一种全局优化算法,其模态解耦结果要优于序列二次规划算法,所以将遗传算法优化后的悬置刚度值作为最终设计方案。试验测试了优化后悬置处振动情况,将优化前后试验数据进行对比,优化后车架及驾驶室支座加速度均小于优化前,且悬置系统共振减少,显著提升了动力总成悬置系统的隔振性能。
[Abstract]:With the improvement of technical level, the working ability of construction machinery is no longer the only index to judge mechanical equipment. The level of vibration and noise is the most important condition to be recognized by the market. As the main vibration source of the vehicle, the powertrain is mounted on the frame by mounting. The unbalanced inertia force and torque ripple are transmitted to the cab through the frame. It has a great influence on the comfort of the whole vehicle. A reasonably designed powertrain mount system can effectively reduce the transmission of vibration to the frame and cab. It can also avoid premature damage caused by excessive vibration. In this paper, the problem of excessive vibration in a certain type of loader is studied, and the experimental results are found. The mount system of powertrain has resonance at multiple rotational speeds, and the mount isolation rate is not high, so it is necessary to optimize the design of powertrain mount system. The design idea and vibration isolation analysis method of powertrain mount system are grasped, and the six degree of freedom model of power assembly mount system is established by using Lagrange method. The natural frequency characteristic, the energy decoupling rate and the dynamic response characteristic of the powertrain mount system are analyzed. The basic parameters of the powertrain mount system are obtained by experiments, including the mass center position of the powertrain. The moment of inertia and inertia product, mounting position, mounting angle and stiffness value. According to the dynamic model of powertrain mount system, the modal calculation program of mount system is compiled based on MATLAB software. And compared with the multi-body dynamics software ADAMS, the calculation results are accurate and reliable, and the direction of optimal design of the powertrain mount system is obtained. The mounting parameters are taken as the optimization variables. The energy decoupling rate of six degrees of freedom and the minimum amplitude of the dynamic reaction force at the mount are the objective functions, and the optimization model of the powertrain mount system is established. Based on MATLAB/GUI platform, the optimal design software of powertrain mount system is developed. The optimization algorithm adopts sequential quadratic programming algorithm and genetic algorithm, which can realize the modal calculation of the mount system. Optimization design and dynamic response analysis are used to optimize the design of this type of powertrain mount system. The decoupling schemes obtained by the two optimization algorithms are compared. As a global optimization algorithm, genetic algorithm (GA) has better modal decoupling results than sequential quadratic programming (SQP). So the optimization of the genetic algorithm after the mount stiffness as the final design scheme. Test the vibration of the optimized mount, and compare the test data before and after the optimization. The acceleration of the frame and cab support after optimization is lower than that before the optimization, and the resonance of the mounting system is reduced, which improves the vibration isolation performance of the powertrain mount system.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH243

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