基于模态参数计算边界条件的方法

Boundary Condition Identification Based on Modal Parameter

提出了一种计算结构边界支撑刚度的新方法。该方法以结构的实测模态参数为基础,利用结构在无支撑条件下低阶固有频率为零这一特点,通过逆推计算来确定结构的边界支撑刚度。该方法也可用来预测边界条件改变时固有频率和固有振型的变化规律。通过两个理论实例对该方法进行了解释和验证,计算结果表明,该方法是正确的和有效的。该方法已成功地应用于印刷机边界支撑刚度的识别,并发现了印刷机安装过程中的支撑不对称性。

This paper presents a new method based on experimental modal parameters to identify the installation stiffness of a structure. According to the characteristic that the low eigenfrequencies of a free structure are zero, the boundary stiffness can be identified by a converse calculation. The method also allows to predict the eigenfrequencies and eigenmodes for changed boundary condition. Furthermore, the new method is explained and validated by two theoretical examples. The identification results show that the method is correct and effective. The method is successfully applied to a printing unit of a sheet-feed printing machine. The identified stiffness points out that the printing unit is unevenly installed.