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.

In most structural members, strength tends to decrease as the member size increases. This phenomenon is known as scale effect. Many experiments investigating the impact of scale effects on RC structures have already been conducted. However, since few laboratories have the capacity to test large-scale specimens, few experimental investigations have tested near full-scale RC members. This paper investigates the scale effect in reinforced concrete members subjected to shear loading. Two different sized test specimens were prepared and tested. The results clearly indicate that the member strength decreases as its size increases. The Japanese building code, an empirically-based code with no scale effect parameter in the shear formulas, generates overly-conservative predictions for full-scale members. Using plane concrete monotonic compression strength data, a formula defining the shear strength of reinforced concrete members is proposed. Experimental results show that the proposed formula for computing ultimate strength agrees better with the experimental data than existing formulas.

Nonlinear finite element analyses of RC beam-column joint specimens that exhibit shear failure under cyclic lateral loading were conducted to investigate their fracture modes and post-peak behavior. Response mechanisms such as cyclic deterioration and shear resistance were investigated. In performing the analyses, spatial discretization, modeling of bond behavior and the type of loading were considered. The macro-scale model for predicting the joint capacity proposed by Shiohara is reviewed and the validity of his hypotheses are rigorously investigated through comparison of the observed and calculated results.

Seismic design provisions for beam-column joints in the AIJ guidelines are based mainly on earlier experimental studies. However, it is necessary to establish a more rational, performance-based design method, especially for joints subjected to two directional seismic forces. This can be accomplished by analytical study of the stress transfer mechanisms in joints. In order to understand the progression of damage in joint concrete, accumulated absorbed strain energy for concrete and reinforcement was calculated from the results of FEM analysis. The stress transfer mechanisms and progression of damage in concrete and reinforcement provide a basis for establishing a more rational, performance-based design method for RC structures.

Over the past years techniques for non-linear analysis have been enhanced significantly via improved solution procedures, extended finite element techniques and increased robustness of constitutive models. Nevertheless, problems remain, especially for real world structures of softening materials like concrete. The softening gives negative stiffness and risk of bifurcations due to multiple cracks that compete to survive. Incremental-iterative techniques have difficulties in selecting and handling the local peaks and snap-backs. In this contribution, an alternative method is proposed. The softening diagram of negative slope is replaced by a saw-tooth diagram of positive slopes. The incremental-iterative Newton method is replaced by a series of linear analyses using a special scaling technique with subsequent stiffness/strength reduction per critical element. It is shown that this event-by-event strategy is robust and reliable. First, the example of a large-scale dog-bone specimen in direct tension is analyzed using an isotropic version of the saw-tooth model. The model is capable of automatically providing the snap-back response. Next, the saw-tooth model is extended to include anisotropy for fixed crack directions to accommodate both tensile cracking and compression strut action for reinforced concrete. Three different reinforced concrete structures are analyzed, a tension-pull specimen, a slender beam and a slab. In all cases, the model naturally provides the local peaks and snap-backs associated with the subsequent development of primary cracks starting from the rebar. The secant saw-tooth stiffness is always positive and the analysis always ‘converges’. Bifurcations are prevented due to the scaling technique.