NEESR-CR: Steel Truss Systems with Enhanced Seismic Safety and Performance

该奖项是NSF 09-524项目招标“小乔治·e·布朗地震工程模拟（NEES）研究网络（NEESR）”竞赛的结果，包括德克萨斯大学阿灵顿分校（领奖）和瓦尔帕莱索大学（次级奖）。该合同将利用明尼苏达大学的NEES设备站点，命名为多轴组件测试（MAST）实验室。本研究的目的是通过研究两种钢桁架体系：特殊桁架弯矩框架（STMFs）和交错桁架框架（STFs），以提高建筑结构的抗震安全性和抗震设计水平。由于STMFs和stf能够实现大的无柱楼面空间，因此它们是结构工程师独特而有价值的选择。然而，尽管STMFs和stf提供了广泛的结构、建筑和经济效益，但关于这些系统的抗震性能的研究数据有限。由于先前对STMFs的测试不能充分反映当前设计和详细设计的实践，因此通过进一步的研究可以大大改进STMFs的设计方法和信心。尽管工程界对此有着浓厚的兴趣，但由于缺乏研究，STFs在地震区的应用受到了限制。该项目将促进对STMFs和stf系统行为的了解，并建议创新以提高这两种桁架系统的抗震性能。知识优势：NEES-MAST设备将用于对构成STMF或STF基本结构单元的大型子组件施加循环载荷。大规模试验将用于：(1)验证根据最新研究成果建议构建的STMFs的行为；(2)探索可以提高STMFs性能的特定桁架结构；(3)阐明循环荷载作用下stf的体系行为；(4)确定STFs的首选耗能机制。瓦尔帕莱索大学的结构工程实验室将用于检查钢弦杆与空心核心混凝土板之间的剪力钉连接的循环加载性能。此外，分析研究将产生代表STMFs和stf抗震性能的一般非线性分析方法，并为一组使用STMFs或stf的代表性建筑体系生成非线性时程分析数据。本研究结果将促进STMFs和STFs的广泛应用。更广泛的影响：该奖项将支持瓦尔帕莱索大学和明尼苏达大学的本科生参与研究。瓦尔帕莱索大学的PI参与了一项工程教育计划，该计划利用虚拟现实系统引入科学可视化。这些系统将用于创建实验测试和分析模型的三维模型。pi将使用3D模型帮助向专业和学术界传播研究成果。3D模型还将用于开发教育工具，向K-12和本科生介绍地震工程研究活动，地震效应的意义以及建筑结构的功能。教育工具将在公共领域提供，用于虚拟现实系统或与传统的计算机屏幕投影仪一起使用。该项目的数据将存档，并通过NEES数据储存库向公众提供。

This award is an outcome of the NSF 09-524 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)" competition and includes the University of Texas, Arlington (lead) and Valparaiso University (subaward). This award will utilize the NEES equipment site at the University of Minnesota, named the Multi-Axial Subassemblage Testing (MAST) Laboratory. The goal of this research is to advance seismic safety and design of building structures by studying two steel truss systems: special truss moment frames (STMFs) and staggered truss frames (STFs). Due to their ability to achieve large column-free floor spaces, STMFs and STFs are unique, valuable options for structural engineers. However, although STMFs and STFs offer a wide range of structural, architectural, and economical benefits, limited research data is available on the seismic performance of these systems. Because previous tests on STMFs do not adequately reflect the current practice in design and detailing, substantial improvement in design methodology and confidence could be gained for STMFs by further research. Despite the strong interest among the engineering community, the application of STFs to seismic regions has been restricted due to lack of research. The project will advance knowledge about the system behavior of STMFs and STFs and recommend innovations to improve the seismic performance of these two truss systems.Intellectual Merit: The NEES-MAST facility will be used to impose cyclic loading on large-scale subassemblages that comprise the fundamental structural unit of a STMF or STF. The large-scale tests will be used to: (1) verify the behavior of STMFs constructed according to recommendations from recent research results; (2) explore specific truss configurations that could enhance the performance of STMFs; (3) clarify the system behavior of STFs under cyclic loading; and (4) identify preferred energy dissipation mechanisms for STFs. The structural engineering laboratory at Valparaiso University will be used to examine the cyclic loading performance of shear-stud connections between steel chord members and hollow core concrete planks. In addition, analytical studies will lead to general nonlinear analysis methods that represent the seismic behavior of STMFs and STFs and generate nonlinear time history analysis data for a set of representative building systems that utilize STMFs or STFs. Results from this research will promote wider use of STMFs and STFs.Broader Impacts: This award will support undergraduate students at Valparaiso University and the University of Minnesota to participate in the research. The PI at Valparaiso University participates in an engineering education initiative to introduce scientific visualization using virtual reality systems. These systems will be used to create three-dimensional (3D) models of both the experimental tests and analytical models. The PIs will use the 3D models to aid dissemination of the research results to the professional and academic communities. The 3D models will also be used to develop educational tools to introduce K-12 and undergraduate students to earthquake engineering research activity, the significance of earthquake effects, and the functions of building structures. The educational tools will be made available in the public domain for use in virtual reality systems or with a traditional computer screen projector. Data from this project will be archived and made available to the public through the NEES data repository.