SP-237CD This CD-ROM is a collection of 19 papers presented at a workshop sponsored by Joint ACI-ASCE Committee 447, Finite Element Analysis of Reinforced Concrete Structures, and JCI Committee 016SP, in Maui, Hawaii, USA, in November 2003. A broad range of topics was addressed, including the creation of new experimental data sets for use in developing, calibrating, and validating models; the development and validation of plain, reinforced, and fiber-reinforced concrete constitutive models; new approaches to simulating the response of reinforced concrete continua; new element formations to enable improved simulation of component response; and new computational techniques.

Code procedures for the seismic design of reinforced concrete structures are increasingly incorporating performance-based criteria, with ‘push-over’ analyses becoming an accepted means of demonstrating sufficient energy-absorbing capacity. Hence, in concrete frame structures containing shear-critical structural elements, the post-peak load-deformation response of these members becomes of practical importance. A series of shear-critical beams was tested recently, patterned after the classic set of beams tested by Bresler and Scordelis forty years ago. In the current tests, particular attention was paid to capturing the post-peak response. The details and results of these beams are presented, providing data useful in testing and calibrating analytical procedures. Nonlinear finite element analyses were undertaken to determine current ability to accurately model post-peak ductility in shear-critical members. Results indicate that current procedures are of marginally acceptable accuracy, and that further developmental work is warranted. A case study, involving a large concrete frame structure built in a high seismic region and containing shear-deficient members, is discussed. This case underscores the importance of accurately calculating the post-peak ductility of shear-critical beams.

Analytical studies for the biaxial behavior of RC columns with square cross section subjected to earthquake ground motion are presented. The objective of this study is to estimate the effect of biaxial bending on RC columns. This study extends an existing 2D lattice model to three dimensions. The 3D lattice model can offer reasonable prediction of the shear-carrying capacity of RC members. By comparing analytical results with the experimental results of shaking table tests on two RC columns, it has been confirmed that the 3D lattice-model analysis can reasonably predict the biaxial behavior of RC columns subjected to the bilateral ground motion. In addition, it is found that analysis considering the buckling of reinforcement can accurately predict the seismic response and energy dissipation capacity of RC columns.

After the Hanshin-Awaji earthquake, the volume of lateral reinforcement used in reinforced concrete structures in Japan was increased to improve seismic performance. Although a large volume of closely spaced lateral reinforcement will be effective in preventing elastic buckling of the longitudinal reinforcement, it will not prevent plastic buckling. Under severe earthquake loading, longitudinal reinforcement will be subjected to large reversed-cyclic deformation demands into the plastic regime in tension and the buckling regime in compression. The authors presented the results of low cycle fatigue testing of deformed bars and examination of failure criteria for these bars.

A Cyclic Softened Membrane Model (CSMM) was developed to rationally predict the cyclic shear responses of reinforced concrete (RC) elements, including the pinching effect in the hysteretic loops, the shear stiffness, the shear ductility and the energy dissipation capacities1, 2. This CSMM model was verified by the tests of fifteen RC panels at the University of Houston. Test results confirmed that the orientation of the steel bars and the percentage of steel in a panel are the two most important variables that influence the cyclic response of RC panel elements.Using OpenSees as a framework, the concept of the CSMM was simplified from a 2-D model into a 1-D model and implemented into a finite fiber element program for the prediction of concrete frame structures subjected to cyclic or dynamic loading. The developed program is validated by the reversed cyclic load tests of a reinforced concrete column and by the shake table tests of a prestressed concrete frame. The CSMM has recently been implemented into an OpenSees-based finite element program for a 2-D RC element that will allow structural engineers to predict the monotonic, cyclic and dynamic responses of structures containing walls. This 2-D RC element is validated in this paper by the prediction of the monotonic responses of two RC panels subjected to shear stresses.