有限元模型修正的虚拟拉直算法  

Pseudo-straighten algorithm for updating finite element model

作　　者：周星德[1] 林小国[1] 徐艳红[1] 

机构地区：[1]河海大学工程力学系,江苏南京210098

出　　处：《振动工程学报》2008年第2期152-156,共5页Journal of Vibration Engineering

基　　金：江苏省第二批"六大人才高峰"资助项目(2005528712);江苏省自然科学基金资助项目(BK2003083)

摘　　要：在拉直算法的基础上,提出了一种新的有限元模型修正方法。拉直算法主要适合于模型修正模型中的约束方程不出现矛盾方程的情况,而对于出现矛盾的约束方程,修正效果可能会很差,其主要原因是修正变量较少,这也导致了拉直算法不适合于含高阶实验模态数据的修正。因此,为了避免矛盾方程的出现和获得可行的修正模型,提出增加带宽的方式(即附加虚拟元素)以增加未知变量的个数,并提出了虚拟拉直修正方法,该方法可有效地修正含高阶模态的实验模态数据。最后以一个平面框架结构为例来说明本文方法的可行性。Based on the straighten algorithm, a new FEM updating method is put forward in the paper. The straighten algorithm is chiefly fit for the case that there are no contravention equations exist in constraint equations of updating model, and the poor updating results will be inevitable with the advent of contravention equation. The main reason is that the updating variables available is less, so the method isn＇t used to update high-order experimental modal data. In order to escape the advent of contravention equation and require a better correcting model, a transaction way of adding band-width （i. e. adding pseudo-elements） is presented to increase the number of unknown variables, and a pseudo-straighten updating algorithm is suggested. The presented method can effectively revise the experimental modal data with high-order mode. an example of plane frame structures is showed to demonstrate the feasibility of the proposed method.

关 键 词：实验模态数据 有限元模型 虚拟拉直运算 

分 类 号：O326[理学—一般力学与力学基础]