Nonlinear analysis of T-shaped concrete walls subjected to multi-directional displacements.

摘要

Structural walls are often used to resist lateral loads applied to buildings. Structural walls have historically been very successful at limiting damage to both structural and non-structural elements. Researchers at the University of Minnesota (UMN), Iowa State University (ISU), the University of Puerto Rico at Mayaguez, and a consulting engineer from the Nakaki Bashaw Group, Inc. in California tested and analyzed five cast-in-place concrete structural walls, three rectangular walls and two T-walls. All of the walls were analyzed using the open source finite element package OpenSees. Both pre- and post-test analysis of the walls was done to understand the simulation capabilities, and improvements that are required to improve the simulation and prediction of the response of the structural walls.;The OpenSees software was modified to include a new concrete model that improves the simulation of the response of concrete flexural members. The details of the concrete models are presented along with the modifications from a concrete model proposed by Chang and Mander in 1995.;The global force-displacement response of the structural walls are compared with the responses recorded during the testing at the University of Minnesota's Multi-Axial Subassemblage Testing Facility. The analysis was generally capable of capturing the measured response within 5-10%. The contribution of various displacement components were examined and compared with the contributions from the OpenSees analysis. The final T-wall response was successfully predicted using the modeling technique.;In addition to the global force-displacement, the local responses including the location of the neutral axis, curvature, and strain profiles are examined. The local response was well captured for the post-testing analysis and acceptably predicted for the pretesting analysis.;In general the fiber based modeling approach used in this investigation of the structural walls tested at the MAST facility was very successful at capturing both the global and local responses of both rectangular and non-rectangular walls under various applied loads. Recommendations for the simulation of concrete structural walls are given, and future research to further advance the simulation of concrete structural walls.