Localization Phenomena in Structural Dynamics

该项目延续了早先在具有参数不确定性和不规则性的结构中处理隔振现象的工作，并专注于通过对周期结构的通用理想化模型的研究来产生对局部化的物理机制的基本见解。目前的项目着眼于三个问题：(A)评估和预测工程结构中局部化效应的重要性，(B)为面临结构动力学应用中的不确定性的分析和设计人员开发简明的统计工具，以及(3)使用这些新的技术和见解来发展复杂结构中的振动传递理论。将在多跨梁上进行局部化效应的实验验证。这项工作的影响是显而易见的。许多大型结构，如桁架梁、叶轮机械转子、潜艇船体、架空电力线路等，都是周期性的。它们的设计和分析都是基于周期是完美的假设。情况并非如此，周期性结构通常对制造公差中的微小不规则性非常敏感。忽视这些变化可能会导致错误的结果和严重的后果。这项研究的重点是通过开发大型周期结构振动分析的新技术来纠正这个问题。

This project continues work initiated in an earlier effort dealing with the phenomenon of vibration isolation in structures with parametric uncertainties and irregularities, and focusing on generating fundamental insights into the physical mechanisms of localization from the study of generic idealized models of periodic structures. The current project looks at three issues which are (a) the evaluation and prediction of the significance of localization effects in engineering structures, (b) the development of concise statistical tools for the analyst and designer confronted with uncertainties in structural dynamics applications, and (3) the use of these novel techniques and insights to develop a theory for vibration transmission in complex structures. An experimental verification of localization effects will be performed on a multi-span beam. The impact of the work is clear. Many large structures, i.e., truss beams, turbomachinery rotors, submarine hulls, overhead power lines, etc., are periodic. Their design and analysis is based on the assumption that the periodicity is perfect. This not the case, and often periodic structures can be highly sensitive to small irregularities in manufacturing tolerances. Neglecting these variations may lead to erroneous results and serious consequences. This research focuses on correcting this problem through development of new techniques for vibrational analysis of large periodic structures.