Optimum design and vibration suppression of flexible adaptive structures

对高速度和低能耗的需求不断增加，要求陆地、空间和海洋交通工具尽可能轻量化。这些结构通常具有轻微的阻尼性和柔韧性，并且由于不同的外部扰动可以很容易地在其较低的固有频率附近被激励，这些外部扰动可能与设计阶段所考虑的不同。这可能会导致过度振动，不仅会影响结构系统的性能，还可能导致子系统或部件失效，从而导致整个系统的灾难性失效。传统被动结构的这种性能限制最近激发了人们对开发一种称为智能或自适应结构的新结构的极大兴趣。智能结构是由集成了传感器和执行器的主机结构组成的自适应结构，由控制器引导，能够在时变的环境和运行条件下修改结构的动态响应。智能磁流变(MR)自适应结构被证明是一种在不同环境激励下半主动控制振动的可行而有效的方法。这些结构可以有效地利用结构的运动来利用自适应可调磁流变装置来开发控制力，并提供被动系统的可靠性，同时保持完全主动系统的通用性和适应性，而不需要强大的电源和昂贵的硬件。这项研究将探索智能磁流变液和阻尼器的独特特性，并将提高嵌入磁流变液或与磁流变阻尼器集成的自适应结构系统在不可预测的环境激励下的性能。建立在数学基础上的高效和创新的分析和设计优化技术，以找到所需的构型，并在广泛的激励下抑制振动。还将进行基本的实验研究，其中将制造概念验证测试自适应结构并对其性能进行评估。

The increase demand for high speed and less energy consumption requires that the land, space and marine vehicles to be as light as possible. These structures are typically lightly damped and flexible and can be easily excited near their lower natural frequencies due to varying external disturbances which may be different than those considered in the design stage. This may lead to excessive vibration which not only can influence the performance of the structural system but also may cause subsystems or components to fail, subsequently causing the catastrophic failure of the whole system. Such a performance limitation of the traditional passive structures has recently motivated considerable interests in developing a new class of structures called smart or adaptive structures. A smart structure is a self-adaptive structure made up of a host structure which is integrated with sensors and actuators and directed by a controller capable of modifying the dynamic response of the structure in the presence of time-varying environmental and operational conditions. Adaptive structures using smart Magnetorheological (MR) fluid have been shown to be a feasible and effective way to semi-actively control vibration under different environmental excitations. These structures can effectively utilize the motion of the structure to develop the control forces using adaptive tunable MR devices and offer the reliability of passive systems, yet maintaining the versatility and adaptability of fully active systems, without requiring large power sources and expensive hardware. The proposed research, with its many fundamental and applied research oriented components, will explore the unique feature of smart MR fluid and dampers and will enhance the performance of adaptive structural systems embedded with MR fluids or integrated with MR damper under unpredictable environmental excitations. Efficient and innovative analysis and design optimization techniques based on the mathematical foundation will be formulated to find a desired configuration and suppress the vibration under a wide range of excitations. Fundamental experimental studies will also be conducted where the proof of-concept test adaptive structures will be fabricated and their performance will be evaluated.