一种基于向量键合图的机构动力学分析方法及在夹持机构中的应用研究

【作者】 张友林；

【导师】 王艾伦；

【作者基本信息】 中南大学 ， 机械设计及理论， 2008， 硕士

【摘要】 随着机构向高速、重载、轻型化方向发展,机构系统功能的优劣越来越取决于机构系统的动力学特性。因此,针对在机构系统动力学分析中,键合图法难以实现复杂机构系统建模的问题,提出了一种基于键合图的机构等效动力学分析法。本文致力于提出一种适用于复杂机构系统领域的动力学建模方法。为此,首先综述了机械动力学分析方法中一般键合图法建模的发展历史和研究现状,阐述了键合图法建模的基本理论。通过综合有关键合图建模的许多文献资料得出由于一般键合图只有标量的概念,无法实现复杂机构系统和空间机构系统建模,而向量键合图法采用了向量表达来代替标量表达,可以弥补一般键合图法建模中的不足。由于键合图模型和物理模型在结构上具有对应关系,对于复杂的机械系统,向量键合图法能实现建模,但所得模型也较复杂,不易于仿真分析。为了使键合图法更加简单地实现复杂平面机构系统以及空间机构系统的建模,本文将经典等效动力学分析法进行改进,并将其与键合图法结合,对复杂的平面机构系统,本文提出了基于一般键合图的机构等效动力学分析法;并在此基础上,针对复杂的空间机构系统,进一步提出了基于向量键合图的机构等效动力学分析法,实现了简单快速建模。本文运用此方法实现了大型锻造操作机夹持机构的动力学建模,对夹持瞬间的动力学特性进行了仿真分析,仿真结果表明所建立的系统动力学模型是正确有效的,与传统的动力学分析方法相比,模型正确且更具简明性,从而将键合图的应用推广到复杂多体系统建模领域,为键合图法的进一步研究奠定了基础。更多还原

【Abstract】 With the development of mechanism becoming high speed, heavy load and light duty, the system function is more and more decided by its dynamic performance. Since the bond graph has been widely used in modeling in many fields, but it’s very difficult to model the complex mechanism system , so a method of equivalent dynamic analysis based on bond graph has been proposed aim at solving this problem.First the method of bond graph modeling in mechanical field has been summarized, including the research status quo and development history. According to many reference, it’s very difficult to use generic bond graph to model the complex mechanism because of its scalar quantity. So vector bond graph has been used to meet the difficulty. Since the equivalent model is very simple, and the elastic deformation and moment of inertia of the mechanism component have been considered by this method, so a equivalent dynamic analysis method based on bond graph has been proposed which includes the method of equivalent dynamic analysis based on general bond graph and the method of equivalent dynamic analysis based on vector bond graph. This new method can be used to model the gripper mechanism of the large-scale forging machine. According to the results of the new method which has been used to model the gripper mechanism, it shows that the model is correct and effective. And it is more compact compared with the traditional dynamic analysis method. So the bond graph method has been extended to model the complex multi-body mechanism system.更多还原