Damage and Instability Detection of Civil Large-scale Space Structures Under Operational and Multi-hazard Environments based on Change in Macro-geometrical Patterns/Shapes

土木结构，如体育场馆，竞技场和体育馆通常是为数百甚至数千人聚集的场所而建造的。这种结构的屋顶可能倒塌，可能危及许多人的生命。本研究的重点是一个自动结构健康监测系统的大型圆顶，可以提供早期预警的结构问题，从不稳定或损坏的结构构件导致崩溃。早期预警可以促进关于维修或拆除的决策，从而为公众和业主带来无忧的结构。该系统具有保护历史结构的潜在用途（例如，大教堂），以验证圆顶结构的维修是否适当，并评估这些结构在地震或强风事件后的健康状况。这项研究的目的是开发创新而实用的方法，以检测在运行或多种灾害环境下空间结构的损坏和不稳定性。本研究的目的将透过三个研究工作来达成：1）发展一套以结构构件构形之分形型态为基础的损伤侦测方法; 2）发展不同的失稳侦测方法，包括个别构件失稳、节点突跳失稳或动力失稳;以及3）通过无线传感器网络将这些方法与多度量测量（倾斜角、应变和/或加速度）集成以形成结构健康监测系统。目标是实现损坏、不稳定和潜在坍塌的自动预警。虽然投影方法对结构的形状/图案变化起作用，但不需要直接的位移测量。形状/图案变化战略性地反映在倾斜角度、应变和加速度中，这可以容易地测量。这些方法也不需要基线响应数据。所开发的结构健康监测系统可以检测结构的失稳，并能在多种危险环境下工作。

Civil structures such as sports stadiums, arenas and auditoriums are usually built for venues where hundreds or even thousands of people assemble. A possible collapse of roof dome of this type of structure may risk many lives. This research focuses on an automatic structural health monitoring system for large domes that can provide early warning of structural problems from instability or damage to structural members resulting in collapse. Early warning can facilitate decision-making on repair or demolition, leading to worry-free structures for both the general public and the owners. The system has potential use to protect historical structures (e.g., cathedrals), to verify the appropriateness of repairs of dome structures, and to evaluate the health condition of these structures after an earthquake or a strong wind event. The objective of this research is to develop innovative yet practical approaches to detect damage and instability in space structures under operational or multi-hazard environments. This research objective will be achieved through three research tasks: 1) develop an approach to detect damage based on the status of fractal patterns of structural member configuration using fractal geometry; 2) develop different approaches to detect instabilities, including individual members buckling, nodal snap-through instability or dynamic instability; and 3) integrate these approaches through a wireless sensor network with multi-metric measurements (tilt angles, strains and/or accelerations) to form a structural health monitoring system. The goal is to achieve automatic early-warning of damage, instability and potential collapse. Although projected approaches work on the shape/pattern changes of the structure, no direct displacement measurements will be required. The shape/pattern changes are strategically reflected in tilt angles, strains and accelerations, which can be measured easily. These approaches also do not require baseline response data. The developed structural health monitoring system can detect instability and can work under multi-hazard environments.