Collaborative Research: Testing and Analyses of Nonrectangular Walls Under Multi-Directional Loads

合作研究：多向荷载下非矩形墙体的测试和分析——CMS 0324504PI: Cathy French，明尼苏达大学。该项目代表了一项合作分析、实验和教育努力，以研究受多向荷载影响的非矩形结构墙体的行为。在中、高地震活动性地区的结构体系中，非矩形结构墙常用于抵抗侧向荷载和限制变形。尽管这样的墙体系统旨在抵抗沿建筑正交轴的侧向力，但由于实验能力的限制，过去的研究仅限于对这些系统的单向研究，因此为描述其行为而开发的数值模型已经根据这一有限的数据进行了校准。拟议的项目采用了NSF George E. Brown, Jr.地震工程模拟网络（NEES）大型测试设施的首批应用之一，即明尼苏达大学的多轴组件测试（MAST）系统，以实现多向测试要求。该设备是研究的理想选择，因为它能够进行六自由度（6-DOF）控制，包括能够指定每个正交轴的剪力曲线的力矩，以模拟施加在墙体系统上的侧向力的分布。预计多向载荷将对这些非矩形墙体系统的性能产生重大影响，因为它们旨在抵抗侧向力并限制沿建筑物正交轴的变形。来自明尼苏达大学、爱荷华州立大学、波多黎各大学马亚圭斯分校和加州欧文市的一家咨询公司Nakaki Bashaw Group， Inc.的研究人员组成了一个合作团队，他们将实验、分析、设计实践和教育方面的优势和资源结合起来，所有这些都是拟议调查的重要组成部分。所有合作研究人员将远程参与实验，包括测试的操作，该测试将驻留在爱荷华州立大学。智力优势：该项目建立在合作研究团队的综合优势和最新可用的实验能力的基础上，以研究震区的关键结构元件，非矩形结构墙。本项目所进行的分析和实验研究将有助于提高对非矩形墙体系统的行为、分析技术和设计的理解。该项目还将建议对当前建筑规范中建议的非矩形墙体元素的设计和细节进行适当的修改。更广泛的影响：通过计划将测试和模拟纳入三所合作大学的课程，包括代表性不足的群体的参与，该项目具有重要的教育组成部分。实践工程师从项目一开始就参与其中，他与首席研究员一起参与美国混凝土协会建筑规范的制定，确保适当的研究成果可以直接转化为实践，改进非矩形结构墙的细节建议。因此，该项目将改善该国地震地区的基础设施。预计该项目的结果将为MAST系统的未来远程用户提供有价值的信息。这些信息将包括任何观察到的反应壁和十字头变形的文件，以及系统在大作用力混合模式控制下的功能。MAST中远程参与者功能的性能和用户性评估旨在改进远程参与系统。共同项目方在这个项目中有既得利益，积极评估这些能力，因为它们对参与这个项目至关重要。研究数据将通过NSF、George E. Brown Jr.、NEES国家数据存储库提供给研究界。通过该项目在明尼苏达大学购买的任何硬件或仪器都将提供给MAST设施的未来用户。

Collaborative Research: Testing and Analyses of Nonrectangular Walls Under Multi- Directional Loads -- CMS 0324504PI: Cathy French, University of MinnesotaThis project represents a collaborative analytical, experimental and educational effort to investigate the behavior of nonrectangular structural walls subjected to the effects of multidirectional loading. Nonrectangular structural walls are often used to resist lateral loads and limit deformations in structural systems located in regions of moderate and high seismicity. Although such wall systems are intended to resist the lateral forces along the orthogonal axes of the building, past research has been limited to unidirectional studies of these systems due to limitations in experimental capabilities, as such the numerical models developed to describe their behavior have been calibrated to this limited data. The proposed project employs one of the first applications of an NSF George E. Brown, Jr., Network for Earthquake Engineering Simulation (NEES) large-scale testing facility, the Multi-Axial Subassemblage Testing (MAST) System at the University of Minnesota, to achieve the multidirectional testing requirements. This facility is ideal for the investigation as it is capable of six-degree-of-freedom (6-DOF) control including the ability to specify moment to shear profiles about each orthogonal axis to simulate the distribution of lateral forces applied to the wall system. It is anticipated that multidirectional loads will have a significant impact on the behavior of these nonrectangular wall systems as they are intended to resist lateral forces and limit deformations along the orthogonal axes of the building. The collaborative team of researchers from the University of Minnesota, Iowa State University, University of Puerto Rico at Mayaguez and The Nakaki Bashaw Group, Inc., a consulting firm in Irvine, California, bring combined strengths and resources in experimentation, analysis, design practice and education, all of which are essential components of the proposed investigation. All collaborative researchers will remotely participate in the experimentation including the operation of the test which will reside with Iowa State University. Intellectual Merit: This project builds on the combined strengths of the collaborative research team and newly available experimental capabilities to investigate a critical structural element for seismic regions, nonrectangular structural walls. The analytical and experimental studies developed in this project are expected to lead to improved understanding of the behavior, analysis techniques, and design of nonrectangular wall systems. The project will also recommend appropriate modifications to the design and detailing of nonrectangular wall elements suggested in the current building codes. Broader Impact: The project has a significant educational component through plans to incorporate the testing and simulation into the curriculum at the three collaborative universities including the participation of underrepresented groups. The involvement of the practicing engineer from the beginning of the project, who along with the Principal Investigator is involved in the development of the American Concrete Institute Building Code, ensures that the appropriate research findings may be translated directly into practice with improved detailing recommendations for nonrectangular structural walls. As such, this project will improve the nation's infrastructure in seismic regions. It is also anticipated that the results of this project will lead to valuable information for future remote users of the MAST system. This information will include documentation of any observed deformations of the reaction wall and crosshead, as well as the ability of the system to function under mixed mode control with large applied forces. The performance and userability evaluations of the remote participant capabilities within the MAST are intended to lead to an improved system for remote participation. The Co-PIs have a vested interest within this project to actively evaluate these capabilities as they are essential to their participation in this project. It is intended that the research data be made available to the research community through the NSF, George E. Brown Jr., NEES National Data Repository. Any hardware or instrumentation purchased at the University of Minnesota through this project will be available to future users of the MAST facility.