ABSTRACT

Collaborative Research: Testing and Analyses of Nonrectangular Walls Under Multi- Directional Loads -- CMS 0324504

PI: Cathy French, University of Minnesota

This 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.

Please report errors in award information by writing to: awardsearch@nsf.gov.