Performance Assessment of Shear-critical Reinforced Concrete Plane Frames

Current analysis procedures for new reinforced concrete structures are typically based on linear-elastic principles. However, under certain conditions, it may be necessary to analyze a structure to more accurately predict its structural behaviour. Such an analysis can be performed using nonlinear analysis procedures which typically require specialized software. This type of software is limited in number and most available programs do not adequately capture shear-related influences, potentially severely overestimating strength and ductility in shear-critical structures. The purpose of this study is to develop and verify an analytical procedure for the nonlinear analysis of frame structures with the aim of capturing shear-related mechanisms as well as flexural and axial effects. A previously developed analysis program, VecTor5, is further developed for this purpose. Originally formulated in the early 1980s at the University of Toronto, VecTor5 is based on the Modified Compression Field Theory (MCFT) and is capable of performing nonlinear frame analyses under temperature and monotonic loading conditions. Although providing generally satisfactory simulations, there are a number of deficiencies present in its computational algorithms. This study consists of three major parts: improvement of the original analysis procedure for monotonic loading conditions, expansion of the procedure for general loading conditions including the special cases of cyclic and reversed-cyclic loading, and further development of the procedure for dynamic loading conditions including time-varying base accelerations, impulse, impact and blast forces, initial mass velocities, and constant mass accelerations. Each part is supported by verification studies performed on a large number and variety of previously tested structures available in the literature. In addition, considerations in nonlinear modelling are discussed with the aim of providing guidelines for general modelling applications. Analyses of 63 previously tested structures, half of which are shear-critical, demonstrate that the developed analytical procedure is highly successful in simulating the experimental responses in terms of load-deflection response, reinforcement strains, crack widths, failure mode, failure displacement, total energy dissipation, displacement ductility ratio, and post-peak vibrational characteristics.Ph