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

体育场馆、竞技场和礼堂等民用建筑通常是为数百甚至数千人聚集的场馆而建的。这种类型的屋顶穹顶可能会倒塌，可能会危及许多人的生命。本研究致力于大型穹顶结构健康自动监测系统的研究，该系统能够对结构失稳或破坏导致结构倒塌的结构问题提供早期预警。早期预警可以帮助做出维修或拆卸的决策，为公众和业主带来无后顾之忧。该系统有可能用于保护历史建筑(如大教堂)，验证穹顶结构修复的适当性，以及在地震或强风事件后评估这些结构的健康状况。这项研究的目的是开发创新而实用的方法，以检测在作战或多种危险环境下空间结构的损坏和不稳定性。本研究的目标将通过三个研究任务来实现：1)开发一种基于结构构件构型的分形图状态的损伤检测方法；2)开发不同的检测失稳的方法，包括单个构件的屈曲、节点的突跃失稳或动力失稳；以及3)通过无线传感器网络将这些方法与多个量度(倾角、应变和/或加速度)相结合，形成结构健康监测系统。其目标是实现对损害、不稳定和潜在坍塌的自动预警。虽然投影方法会影响结构的形状/图案变化，但不需要进行直接的位移测量。形状/图案的变化在战略上反映在倾斜角、应变和加速度上，这些都很容易测量。这些方法也不需要基线响应数据。开发的结构健康监测系统能够检测结构的失稳，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.