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

这个奖项是一个结果的NSF 09-524计划征求“乔治E。小布朗地震工程模拟网络（NEES）研究（NEESR）”竞赛，包括德克萨斯大学，阿灵顿（领导）和瓦尔帕莱索大学（子奖）。该奖项将利用明尼苏达大学的NEES设备站点，命名为多轴子组件测试（MAST）实验室。本研究的目的是通过研究两种钢桁架结构体系：特殊桁架框架和交错桁架框架，来提高建筑结构的抗震安全性和设计水平。由于其能够实现大的无柱楼层空间，STMF和STF是结构工程师的独特，有价值的选择。然而，虽然STMF和STF提供了广泛的结构，建筑和经济效益，有限的研究数据是这些系统的抗震性能。由于以前的测试STMF没有充分反映目前的做法，在设计和详细的STMF的设计方法和信心，可以获得实质性的改进，通过进一步的研究。尽管工程界对此有着浓厚的兴趣，但由于缺乏研究，STF在地震区的应用受到了限制。该项目将推进有关STMF和STF的系统行为的知识，并推荐改进这两种桁架系统抗震性能的创新。智力优势：NEES-MAST设施将用于对构成STMF或STF基本结构单元的大型子组件施加循环荷载。大型试验将用于：（1）验证根据最近研究结果的建议建造的STMF的行为;（2）探索可以提高STMF性能的特定桁架配置;（3）阐明STFs在循环荷载下的系统行为;（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被用来检查钢弦杆和空心混凝土板之间的剪切螺栓连接的循环荷载性能。此外，分析研究将导致一般的非线性分析方法，代表STMF和STF的抗震性能，并产生一组代表性的建筑系统，利用STMF或STF的非线性时程分析数据。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，使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（3D）模型。PI将使用3D模型来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。这些教育工具将在公共领域提供，用于虚拟现实系统或传统的计算机屏幕投影仪。该项目的数据将通过NEES数据库存档并向公众提供。

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.