基于ANSYS的混凝土泵车臂架系统流固耦合模态研究

发布时间：2018-02-09 09:30

本文关键词： 臂架系统流固耦合 ANSYS 模态固有频率　出处：《长沙理工大学》2013年硕士论文　论文类型：学位论文

【摘要】：混凝土泵车臂架振动问题是当前研究工程实际应用的热点问题。臂架系统是混凝土泵车的核心结构之一，臂架系统的振动将直接影响浇注效率和泵送质量，且易造成疲劳破坏和臂架折断，因此臂架系统的动力学研究具有重要现实意义。而混凝土的压力脉动引起臂架系统的振动也是一个不容忽视的问题。泵车工作时，臂架的振动与混凝土在输送管内的流动耦合，属于典型的输流管道流固耦合动力学问题，虽然混凝土在管内流速较小，但由于其密度较大且臂架刚度较弱，所以混凝土与臂架之间耦合作用不可忽视。在此，本文基于ANSYS平台，对臂架系统进行流固耦合模态研究。研究工作主要包括以下几个方面： 1．借助于泵车振动动力学模型建立了臂架系统动力学微分方程，并结合ANSYS软件计算原理，对臂架系统流固耦合动力学分析进行理论机理研究，同时介绍了混凝土泵车臂架模态分析机理。 2．为便于模型求解计算，对臂架模型进行了合理简化。选取能较真实模拟实际的有限元单元，建立了五节混凝土泵车臂架系统水平工况有限元模型。 3．基于ANSYS平台，通过APDL命令流编写，对泵车臂架系统进行模态仿真分析。分别模拟混凝土在管道中的输送过程，仿真计算混凝土输送至各节时臂架系统的模态情况，，并与空管时臂架系统的模态进行对比，得出流固耦合作用对臂架固有频率和振型的影响；将空管和全部充满时臂架系统的固有频率进行数值计算，得出考虑流固耦合作用与不考虑流固耦合的固有频率之间的关系。 4．建立了臂架系统三种典型工况模型，分别对其进行模态分析，对比分析各工况下流固耦合模态固有频率和振型；改变臂架厚度值，对臂架进行了仿真模拟，计算结果表明了随着节臂厚度的增加，刚度增强，固有频率不断增大，但当节臂厚度增加到一定值后，固有频率影响较小，此时可以从强度和疲劳的角度对其进行优化设计，实现更为卓越的稳定性。
[Abstract]:The vibration problem of concrete pump truck is a hot problem in actual engineering application. The boom system is one of the core structure of the concrete pump, the vibration of the boom system will directly affect the efficiency of pumping and pouring quality, and easy to cause fatigue damage and broken arm, so the dynamics of the arm system has important practical the significance and concrete. The pressure fluctuation caused by vibration of the boom system is also a problem can not be ignored. When the pump work, the boom vibration and concrete in conveying flow coupling tube, which belongs to the pipeline fluid solid coupling dynamics of the typical problems, although the concrete velocity in the tube is small, but because of its high density and arm stiffness is weak, so between the concrete and the arm coupling effect can not be ignored. In this paper, based on the ANSYS platform, the boom system research on fluid solid coupling mode. The main research work It includes the following aspects:
1., with the help of the vibration and dynamics model of the pump truck, the dynamic differential equation of the boom system is established. Combined with the calculation principle of ANSYS software, the theoretical mechanism of the fluid solid coupling dynamic analysis of the boom system is studied. Meanwhile, the modal analysis mechanism of the concrete pump truck boom is introduced.
2., in order to facilitate the calculation of the model, the jib model is simplified reasonably. The finite element model of the five level concrete pump truck boom system is established by selecting the finite element unit that can simulate the actual situation.
3. based on the ANSYS platform, written by APDL command stream, the modal simulation analysis of the concrete pump truck. Simulate the transport process of concrete in the pipe, the simulation mode of concrete conveyed to each section of the boom system, and in comparison with the modal of empty arm system, the influence of fluid solid the coupling effect of the boom of natural frequency and vibration mode; the natural frequency of pipe and full when the arm frame system for numerical calculation, obtained considering fluid solid coupling and do not consider the relationship between the natural frequency of the fluid solid coupling.
4. established three typical condition model of the boom system, separately carried on the modal analysis, comparison and analysis of the condition of fluid solid coupling modal natural frequency and vibration mode; change the arm thickness value, the boom of the simulation, the calculation results show that with the increase of the arm thickness, stiffness increased, increasing the natural frequency, but when the arm thickness increases to a certain value, the smaller impact of natural frequency, this can optimize its design from the perspective of strength and fatigue, so as to achieve more excellent stability.

【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU646

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