简支-挠性支撑梁的振动特性与轴向压缩稳定性研究

发布时间：2018-03-02 01:14

本文关键词： 柔性多体系统简支梁边界挠性模态分析稳定性　出处：《北京大学学报(自然科学版)》2016年04期 　论文类型：期刊论文

【摘要】：针对可移动简支具有挠性/不确定性的简支梁系统,采用柔性多体系统动力学相对描述方式,建立可描述其整体转动和相对变形的非线性动力学模型,解析结合数值分析了可移动简支刚度对系统模态和轴向压缩稳定性的影响。研究表明,简支梁可移动简支刚度相对梁刚度偏小时,对系统低阶频率、低阶振型和失稳模式影响显著,主要体现在梁的整体转动特性上,且相对描述方式中的低阶振型也与经典梁的模态不同,体现了整体运动对相对变形模态的影响特性;简支梁可移动简支刚度相对梁刚度偏大时,主要对系统高阶频率和振型有一定影响,而对低阶频率、振型和失稳模式的影响很小。此研究成果和认识对于梁构件约束边界设计与柔性多体动力学理论的应用具有重要意义。
[Abstract]:In this paper, a nonlinear dynamic model is established to describe the global rotation and relative deformation of a moving simply supported beam system with flexible and uncertain simply supported beams by using the relative dynamic description of flexible multi-body system. The influence of the movable simply supported stiffness on the modal and axial compression stability of the system is analyzed analytically and numerically. The results show that the moving simply supported stiffness is small relative to the stiffness of the beam, and the frequency of the system is low. The influence of low order mode and instability mode is significant, which is mainly reflected in the whole rotational characteristics of the beam, and the low order mode in the relative description mode is different from the mode of the classical beam, which reflects the influence of the whole motion on the relative deformation mode. When the stiffness of a simply supported beam is relatively large relative to the stiffness of the beam, it has a certain influence on the higher frequency and mode shape of the system, but on the low order frequency, The effect of vibration mode and instability mode is very small. This research result and understanding is of great significance for the design of constrained boundary of beam member and the application of flexible multi-body dynamics theory.
【作者单位】：中国工程物理研究院总体工程研究所;
【基金】：中国工程物理研究院重点学科项目“计算固体力学”;中国工程物理研究院科学技术发展基金(2013A0203007)资助
【分类号】：O327

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