Optimum design and vibration suppression of large flexible smart structures

由于运输成本高，大多数实用结构通常重量轻且柔性。 因此，由于外部干扰的变化，它们可以在其较低的自然频率附近被激励，这些外部干扰可能与设计阶段考虑的干扰不同。这可能随后导致结构不稳定或操作的准确性和精确度的急剧降低。为了缓解这些问题，智能结构技术在许多航空航天、民用和汽车应用中变得越来越重要。智能结构是一种自适应结构，它由集成了离散传感器和执行器的主结构组成，并由控制器控制，能够在时变的环境和操作条件下改变结构的动态响应。 设计和开发实际应用中用于形状和振动控制的智能结构是本提案的长期目标。它打算建立一个平台，在这一领域开发创新方法，并促进这一新技术在加拿大的传播。为了沿着这一目标的实现，本论文将重点研究以下几个方面的问题：一、高分辨率、高动态驱动力的压电线性作动器的设计优化与开发，二、压电线性作动器在智能桁架结构中的设计优化与振动主动控制，三、压电层合复合材料结构的设计优化与振动主动控制，四、压电层合复合材料结构的设计优化与振动主动控制。采用磁流变阻尼器的离散结构的设计优化和半主动振动抑制。在这些问题中，相互作用的学科之间的耦合的协同效应将被探索和考虑耦合效应的数学公式将被开发。 然后，高效和创新的分析和设计优化技术的基础上的数学基础，将制定找到所需的配置，并抑制在广泛的激励下的振动。将进行基础实验研究，其中将产生概念验证测试智能结构，并评估这些测试结构的性能。

Due to the high cost of transportation, most practical structures are typically light weight and flexible.  Thus they can be excited near their lower natural frequencies due to varying external disturbances which may be different than those considered in the design stage. This may subsequently lead to the structural instability or a drastic reduction in accuracy and precision of operation. To alleviate these problems, the smart structure technology is becoming increasingly important in many aerospace, civil and automotive applications. Smart structure is a self-adaptive structure made up of a host structure which is integrated with discrete 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.  The design and development of smart structures for shape and vibration control in practical applications is the long term objective of this proposal. It is intended to establish a platform to develop innovative methodologies in this field and foster the spread of this new technology in Canada. To move along this goal efficiently, the following first-priority problems will be studied: I- Design optimization and development of piezoelectric linear actuator with high resolution and dynamic actuation force, II- Design optimization and active vibration control of smart truss structures using piezoelectric linear actuators; III- Design optimization and active vibration control of piezolaminated composite structures; IV-Design optimization and semi-active vibration suppression of discrete structures using Magneto-Rheological (MR) dampers. In these problems, the synergistic effects of coupling between interacting disciplines will be explored and the mathematical formulation considering the coupling effect will be developed.  Then, efficient and innovative analysis and design optimization techniques based on the mathematical foundation will be formulated to find desired configuration and to suppress the vibration under a wide range of excitations. Fundamental experimental study will be conducted where the proof-of-concept test smart structures will be produced and the performance of these test structures will be evaluated.