附加约束阻尼层的复合材料梁单元建模分析

Beam element model analysis of composite beam with constrained damping layer

复合材料空心圆截面梁是桁架和刚架结构中大量采用的常用构件,而实践证明约束阻尼层能有效改善复合材料空心圆截面梁的动力学特性,但传统的约束阻尼层结构有限元计算方法需要大量的单元,这给大型复杂结构的计算带来了巨大的困难。本文采用Timoshenko梁假定,建立了一类附加约束阻尼层复合材料空心圆截面梁弯曲的数学模型。应用Hamilton原理,采用三节点高次梁单元对构件进行离散化,建立了附加约束阻尼层复合材料空心圆截面梁的梁单元。同传统的锥壳单元相比,该方法极大地减少了计算时间。用实验验证了本文计算结果的正确性,同时也分析了约束层厚度对损耗因子的影响。

The circular hollow composite beam（CHCB） is a general component used in truss and rigid frame, and it has been proved through experiences that the constrained damping layer （CDL） can improve the dynamic character of CHCB. However, for the traditional finite element method （FEM）, large number of elements are needed in the computation procedure for the structures with CDL, which may cause much difficulties in the computation for large and complicated structures. Under the assumption of Timoshenko beam, in this paper, a mathematical model of a bending CHCB with CDL is set up, and through Hamilton principle, the 3-node high order beam element is used to discretize the component, and furthermore a new beam element is set up. Compared with the traditional cone shell element used in model analysis, this method greatly decrease the computing time. The experiment validate the rightness of the computation, and at the same time the influence of the constraining layer thickness on the modal loss factor is analyzed.