虛擬模態振形法建立結構動態模型之研究

Dynamic Modeling of Structures Using Pseudo Mode Shape Method

10.29948/JAE.200607.0001

楊大中(Ta-Chung Yang)；陳孟乾(Meng-Chien Chen)；蒯光陸(Kwang-Lu Koai)

有限元素法 ； 頻率響應函數 ； 模態振形 ； finite element method ； frequency response function ； mode shape

先進工程學刊

1卷1期（2006 / 07 / 01）

1 - 6

繁體中文

複雜結構建模會遭遇元素過多，造成計算的耗時。作模態測試又會因為設備不易架設及時間不予許等問題，無法作完整的測試，僅能獲得少部分資訊。本文利用－虛擬模態振形方法，將次結構頻率響應函數轉換成空間模型的質量、勁度、阻尼矩陣，能夠達到涵蓋較大頻率範圍，這些次結構由原結構組成並能顯示完整結構之頻率響應。本文以一個二維的平面樑為例，驗證此方法的可行性。

Problems of huge amount of elements and time consuming in computation often occur in finite element modeling of complicated structures. Limited modal test data can only be obtained due to testing restrictions, for instance, limited test points and lack of test time during maintenance or overhauling. In this paper, a pseudo mode shape method was proposed to provide adequate spatial models (i.e., mass, damping, and stiffness matrices) to cover more frequency range of frequency response functions of substructures. These substructures can be assembled with mother structures to reveal the vibration response of the complete structures in the frequency ranges. A 2-D beam structure is used to demonstrate the validation of this method.