集装化运输减振系统优化设计研究

发布时间：2018-10-11 19:49

【摘要】：集装化运输是现代后勤保障的主要运输方式之一，精密医疗设备以及高纯度成分血等是应对突发事件、抢险救灾的重要后勤战略物资。由于特殊环境下的运输所造成的高强度冲击与振动常常造成设备损坏、血液失效等故障。本文以精密仪器与设备的集装化运输为研究背景，开展集装化运输减振系统的优化设计研究工作，旨在降低战略物资在集装化运输过程中所受的冲击与振动强度，从而保证重要物资的高效安全运输。首先建立集装箱的有限元模型，并对其进行了模态分析，得出了100Hz频率范围内的各阶模态参数与振型。模态分析结果表明，集装箱的模态振型主要表现为各盖板的弯曲振型，而结构框架的八个角点均为振型节点，且框架梁在20Hz频率范围不存在弯曲振型。根据模态计算结果初步确定了减振机构的固定点为集装箱框架的八个角点及框架梁上的辅助支承点。因此集装箱的弹性体振动就不会通过减振机构传递到减振箱，从而减小了减振箱的振动。其次，建立了集装化运输减振系统垂向考虑易损件的振动动力学方程以及垂向、横向和考虑转动耦合的三自由度系统冲击动力学方程。采用四阶龙格库塔法分别讨论了系统在自振和半正弦脉冲激励下的动力学性能。研究了悬挂角、阻尼比等因素对振动冲击的影响规律。结果表明：自振条件下，减小悬挂角，增大阻尼比，在低频率比区域增大质量比可抑制易损件加速度响应；半正弦脉冲激励下，装载设备的质心位置应尽量与系统几何中心重合，选择较小的悬挂角和适当增大阻尼比，可以减小系统的冲击响应。分析了悬挂式减振系统的主要参数对振动响应的影响，得出了影响规律，并对集装化运输减振系统进行了优化设计。以三个方向加速度响应均方根值之和为联合目标函数，以减振箱位移为约束条件对减振系统弹簧刚度、阻尼及弹簧悬挂角进行了优化，，得出了最佳的减振机构设计参数。最后设计了缩小比例的集装化减振运输系统，并通过试验结果验证了集装化减振系统设计方法及结果的正确性。
[Abstract]:Container transportation is one of the main transportation modes of modern logistics support. Precision medical equipment and high purity blood are important logistic strategic materials to deal with emergency and rescue. Because of the high intensity shock and vibration caused by the transportation in special environment, equipment damage and blood failure are often caused. In this paper, based on the research background of container transportation of precision instruments and equipment, the optimal design of vibration absorber system of container transportation is carried out in order to reduce the shock and vibration intensity of strategic materials in the course of container transportation. So as to ensure the efficient and safe transportation of important materials. Firstly, the finite element model of the container is established, and the modal analysis is carried out, and the modal parameters and modes of each order in the range of 100Hz frequency are obtained. The modal analysis results show that the modal modes of the container are mainly the bending modes of each cover plate, while the eight corner points of the frame are all modal joints, and there is no bending mode in the 20Hz frequency range of the frame beam. According to the modal calculation results, the fixed point of the vibration absorber is determined as eight corner points of the container frame and the auxiliary supporting point on the frame beam. Therefore, the vibration of the elastic body of the container will not be transmitted to the damping box through the damping mechanism, thus reducing the vibration of the damping box. Secondly, the dynamic equations of vibration and shock dynamics of a three-degree-of-freedom system with vertical, transverse and rotational coupling are established. The dynamic performance of the system under the excitation of natural vibration and half-sine pulse is discussed by using the fourth order Runge-Kutta method. The influence of suspension angle and damping ratio on vibration shock is studied. The results show that under the condition of natural vibration, decreasing the suspension angle, increasing the damping ratio, increasing the mass ratio in the region of low frequency ratio can restrain the acceleration response of the damaged parts. The position of the mass center of the loading equipment should coincide with the geometric center of the system as far as possible. The impact response of the system can be reduced by selecting a smaller suspension angle and increasing the damping ratio appropriately. The influence of the main parameters of the suspension damping system on the vibration response is analyzed, the influence law is obtained, and the optimum design of the vibration absorption system for the container transportation is carried out. Taking the sum of the root mean square value of the three directions acceleration response as the joint objective function and the displacement of the damping box as the constraint condition, the spring stiffness, damping and spring suspension angle of the damping system are optimized, and the optimum design parameters of the damping mechanism are obtained. Finally, a small proportion of the container vibration reduction and transportation system is designed, and the correctness of the design method and the results of the system are verified by the experimental results.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U169.3;TB535

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