加筋薄板的自由振动分析

Free Vibration Analysis of Stiffened Thin Plate

加筋薄板是航空领域最常见的结构之一,加强筋对薄板振动模态有显著影响。为改善蒙皮加筋薄板的动力学特性,旨在研究板筋连接单元的动力学建模方法以及加强筋对蒙皮薄板振动的影响机制。首先研究加筋薄板铆接、点焊和滚焊连接形式的有限元建模方法,建立铆接、点焊和滚焊薄板构件的有限元动力学模型;然后探讨单向与双向加筋薄板构件的自由振动模态;最后,分析板筋连接形式和加筋安装方向对薄板振动模态的影响机制。结果表明,加强筋的设计对薄板模态影响明显,滚焊加强筋对薄板构件的模态频率影响相对最大。

It is well known that stiffened plate is one of the most frequently used structures in the aeronantical fields. The impacts of the stiffened pattern on the vibration properties of the skin plate in the aircrafts are obviously. The aim of this paper is to study the dynamical modelling method of the connected structures that include the skin plate and the stiffen beam, and to study the impacts of stiffened pattern on the dynamic properties, so as to improve the dynamical properties of the skin plate structure. Firstly, a finite element analytical method of the connected element that includes the rivet, spat-weld and rolling- weld element was studied. Some finite element models that include the stiffened plate with rivet, spot-weld or rolling-weld connection were built at the same time. Then, the vibration properties of the single -direction and the double -direction stiffened plates were studied. The impacts of connection method and stiffened direction on the structural dynamics were revealed in the end. Results indicate that the stiffened pattern impacts on the vibration mode of the thin plate are obviously and the value of the modal frequeney of the rolling-weld stiffened plate is the maximum.