Torsional -- Bending Vibrations Attenuation Using Piezoelectric Elements

9402802 Kawiecki这个项目的目标是开发一种方法来控制结构元件中的扭转和扭转-弯曲振动。这个问题将用两种方法来解决。其中一种方法是基于利用分布在结构单元上的压电元件的拉伸/压缩作用来产生扭转、弯曲和轴向控制载荷的概念。另一种方法是利用压电膜来改变粘弹性层中剪切应变的分布，从而改善结构的减振特性。该项目涉及实验和数值研究。实验研究将采用三种不同的试件：(1)嵌入一组压电元件以产生扭转和弯曲控制载荷的复合梁，(2)一组压电元件层合在墙上的薄壁铝梁，以及(3)一组ACLD元件层叠在其墙上的薄壁铝梁。在分析工作中，将开发一个能够模拟梁的动力学的有限元程序。制定研究计划以允许在代码开发的每个步骤获得的结果与在实验调查的每个相应步骤获得的结果相关联。在控制实验中，粘结在梁上的压电元件将由一个基于比例和导数控制增益的简单模拟控制系统来驱动。将测试扭转弯曲振动的衰减效果。最终，相同的系统将被用于控制有限元模型。与实际系统行为的关联度将允许对数值模型的准确性进行评估。***

9402802 Kawiecki The objective of this project is to develop an approach to control torsional and torsional-bending vibrations in structural elements. This problem will be solved using two methods. One of the methods is based on a concept of generating torsional, bending and axial control loads using the extension/compression action of piezoceramic elements distributed over the structural element. The other method is based on a concept of improving the damping characteristics of a structure by using a piezofilm to modify the distribution of shear strain in a viscoelastic layer bonded to a structure. The project involves experimental and numerical investigations. The experimental research will be performed with three different specimentss: (1) a composite beam with an embedded set of piezoelements designed to generate torsional and bending control loads, (2) a thin walled aluminum beam with a set of piezoelements laminated to the walls, and (3) a thin-walled aluminum beam with a set of ACLD elements laminated to its walls. In the analytical work, a finite element code capable of modeling the dynamics of the beams will be developed. The research plan is formulated to allow the correlation of the results obtained at each step to code development with the results obtained at each corresponding step of the experimental investigation. In the control experiments, the piezoelements bonded to the beams will be driven by a simple analog control system based on proportional and derivative control gains. The attenuation effectiveness of torsional bending vibrations will be tested. Eventually, the same system will be used to control finite element models. The degree of correlation with real system behavior will allow the evaluation of the accuracy of the numerical model. ***