【作者】 李荣；

【导师】 吴晓明；

【作者基本信息】 厦门大学 ， 机械工程， 2014， 硕士

【摘要】 挖掘机在工程施工中有着极为广泛的应用,其驾驶室隔振性能不仅影响到零部件的使用寿命,还关系到驾驶员的舒适性和工作效率,因此挖掘机驾驶室的隔振性能日益受到消费者的重视,成为提高产品市场竞争力的重要途径。现有车辆驾驶室隔振研究通常以驾驶室为主体,建立单体六自由度动力学简化模型,忽略座椅悬置元件的影响。本文考虑座椅悬置元件的影响,建立了双质量十二自由度动力学模型,研究驾驶室一座椅悬置系统设计不合理引起的人体不舒适性问题,对模型进行了分析和优化,在尽量满足频率匹配的同时提高系统模态解耦率,提高悬置系统的隔振性能。本文主要研究内容如下:(1)针对驾驶室的结构和振动情况,归纳出工程车辆中人体全身振动的一种评价方案,建立了驾驶室一座椅悬置系统双质量十二自由度刚体振动力学模型和数学模型。(2)分别用Matlab软件和Adams软件对悬置系统模型的固有频率和能量解耦率求解,并将两者的结果进行对比分析,分析结果为悬置系统的优化设计指明了方向。在发动机怠速工况下对悬置系统进行了进一步时域和频率仿真分析。(3)确定了驾驶室—座椅悬置系统优化设计数学模型的目标函数、设计变量和约束条件,并对模型进行健壮性测试和灵敏度分析,为下一步的优化计算奠定了基础。用ADAMS/view模块中的SQP仿真优化算法对优化问题进行优化求解得到优化结果。将优化前后结果仿真进行比较,结果表明优化后的悬置系统的固有频率分布范围和能量解耦率都有了明显改善。(4)考虑到在实际生产中很难从工艺上保证橡胶悬置元件静刚度的精确性,本文用蒙特卡罗方法对优化方案进行鲁棒性分析,表明了优化方案的鲁棒性较高。更多还原

【Abstract】 The excavator is wildly used in the engineering construction.The performance of its cab not only affect the service life of its parts but also be in relation to the driver’s comfort and work efficiency.So the vibration isolation performance of the excavator cab is taken seriously by consumers,and it’s an important way to enhance the competitiveness of the market.The existing vehicle cab isolation study usually took the cab as the main body,and established dynamic model for the sake of simplicity,but ignored the influence of the seat isolators.In this paper,considering the influence of the seat isolators,double quality 12 free degrees dynamic model was established in order to research the human body discomfort caused by unreasonable design of the cab-seat suspension system.Then the model was analyzed and optimized,the system decoupling rate was raised when the frequency was matched to improve the vibration isolation performance of the suspension system.In this paper,the main contents were as follows:(1)According to the structure and vibration of the cab,an evaluation scheme about body vibration in the engineering vehicle was summed up.Rigid body vibration mechanics model and mathematic model of the cab-seat suspension system were set up.(2)Adams software and Matlab software were used to solve the intrinsic characteristics of suspension system respectively,and the results of both were compared,and the results pointed out direction of the optimum design of the suspension system.The simulation analysis in time and frequency domain were done to analyze the dynamic characteristics of the suspension system for further more.(3)The objective function,design variable and constraint condition of the cab-seat optimization design was determined.The perimeter study and sensitivity analysis of the of the model was done.The SQP simulation optimization algorithm in the Adams/view was used to solve the optimization problem.The results before and after optimization were compared,and showed that the distribution of natural frequency and the energy decoupling rate were improved significantly.(4)Because it was difficult to guarantee the accuracy of the static stiffness of rubber isolator from craft in actual production,the monte carlo method was used for robustness analysis,and it confirmed that the robustness of the optimized scheme was high.更多还原