机构运动弹性动力学普遍方程的研究

本文首次采用等参有限单元,建立了一个为一般机构广泛适用的运动弹性动力学普遍方程。在不附加任何“运动学”假设的情况下,作为自然的结果,方程的质量阵是正定、协调的常数阵;方程中不存在两类时变的非对称系数项,即所谓的“陀螺阻尼”项和“离心动刚度”项。因此,该方程无论在形式上还是在生成及求解方面,都要较其它同类型方程简单。此外,基于一维等参梁单元,本文还具体导出了具有杆状构件的平面连杆机构的弹性动力学模型,并给出了一个铰链四杆机构的算例。

Investigation of the Generalized Equation of Motion for KED Analysis of Flexible Mechanisms

A generalized equation of motion for KED analysis of general flexiblemechanisms has been developed by utilizing newly isoparametric finite elementtheory in this paper. As a natural result, the mass matrix is a positive definiteconsistent and time-independent one, and the two time-dependent and nonsymmetricmatrice, that is, the "gyroscopic damping" and "centrifugal stiffness" ones,don't exist in the equation. Thus the equation with concise form may be derivedand solved easily. Also based on the one-dimensional isoparametric beamelements, the equation for some flexible planar linkages has been derived indetail, and a numerical result of a planar for-bar linkage is presented in thepaper.