CAREER: Innovative Structural Systems for Multi-hazard Resistance Using Steel Plate with Cutouts

该教师早期职业发展（CAREER）计划拨款将通过战略性地去除成分钢板中的材料（即引入工程切口）来进行研究，以创建新的增强型结构系统。 承受地震或风引起的极端横向载荷的结构系统，当它们能够承受大的变形而不断裂时，就能抵抗倒塌。 这种被称为延展性的特性保护了居民的生命，因为建筑物可以变形而不会倒塌。 依靠钢板剪切变形来发展延性的典型结构系统受到剪切屈曲和断裂潜力的挑战。 这项研究试图彻底改变依赖于韧性剪切变形的构造系统。 创新的方法是通过战略性地从板中去除材料而不是添加更多的材料来提高延性和能量耗散能力。 这个项目将开发剪切模式和基础科学，将剪切变形转化为抵抗屈曲的较小的韧性机制。新的结构系统有潜力改善建筑环境在承受极端横向荷载时的性能。该项目的方法包括将整体剪切变形转化为局部延性屈服机制，以抵抗屈曲，提高刚度，表现出稳定和完全的滞回性能，并允许调整结构行为。 本文的计算和试验研究将使人们对环形和屈服杆滞回元件的力学机理有一个新的认识。 通过以下方式获得有关创建延性剪切行为的方法的基本知识：1）计算探索抗屈曲机制的切口的尺寸，形状和布局，2）开发调整行为的方法，3）通过小型和大型实验验证概念，以及4）结构系统级建模。 相关的教育计划将通过以下方式将视觉演示和实践活动注入结构工程课程：1）为K-12外展开展和录制实践活动，2）制作制作精良的外展活动，实验和关键演示视频，然后3）创建与结构工程相关的视频和说明的在线仓库。

This Faculty Early Career Development (CAREER) Program grant will pursue research to create new enhanced structural systems by strategically removing material (i.e. introducing engineered cutouts) in constituent steel plates. Structural systems subjected to extreme lateral loads due to earthquake or wind resist collapse when they can sustain large deformation without breaking. This property, known as ductility, protects the lives of inhabitants because buildings can deform without collapsing. Typical structural systems that rely on shear deformations in steel plates to develop ductility are challenged by shear buckling and the potential for fracture. This research attempts to revolutionize structural systems that rely on ductile shear deformations. The innovative approach is to improve ductility and energy dissipation ability by strategically removing material from the plates rather than adding more material. This project will develop cutout patterns, and the underlying science, to convert shear deformations into smaller ductile mechanisms that resist buckling. The new structural systems have the potential to improve the performance of the built environment when subjected to extreme lateral loads.The project's approach involves converting global shear deformations into local ductile yielding mechanisms in a way that can resist buckling, develop increased stiffness, exhibit stable and full hysteretic behavior, and allow structural behavior to be tuned. The computational and experimental studies will lead to a new understanding of the mechanics of ring-shaped and yielding link hysteretic elements. Fundamental knowledge about approaches for creating ductile shear behavior will be discovered by 1) computationally exploring size, shape, and layout of cutouts for buckling resistant mechanisms, 2) developing methods to tune behavior, 3) validating concepts through small- and large-scale experiments, and 4) structural system level modeling. A related educational plan will inject visual demonstrations and hands-on activities into structural engineering curricula by 1) conducting and videotaping hands-on activities for K-12 outreach, 2) creating well-produced videos of the outreach activities, experiments, and key demonstrations, and then 3) creating an online warehouse for videos and instructions related to structural engineering.