Analytical model for reinforced concrete shear wall structures

A new analytical model with 8 external DOF is developed for inelastic static analysis of multistory reinforced concrete shear wall structures under general loading. The proposed model is constructed based on a new combined macroscopic and microscopic modeling techniques to minimize the required calculations and the experimental-based input data.;The model is comprised of two sub-panels, each with 8 DOF. These are; an elastic panel at the top of the wall which is attached to a spreading plastic panel at the lower portion. Top elastic panel represents the response of relatively uncracked segment of the wall. A plane-stress finite element, developed for shear walls, is modified and used for this panel.;The height of the elastic panel is variable. Starting with the full height, It's height will be reduced in accordance with the expansion of the plastic panel at the bottom of the wall. A new strain-based method is utilized to monitor the expansion of the plastic panel.;The plastic panel provides the overall inelastic response of the shear wall model. This panel is discretized and lumped into two different sub-systems. The first system, a truss-type element, consists of four inelastic vertical spring assemblies which provides a complete coupling of the flexural and the axial response mechanisms. The flexural resistance of both the boundary elements and the web are presented by these assemblies. Each assembly includes three separate inelastic springs, arranged in parallel and series, to facilitate the material-level modeling.;The second sub-system represents the inelastic response of the web section in the plastic panel by a non-prismatic beam-type element. This element enforces a full interaction between the flexural and the shear deformation mechanisms using a flexibility-based formulation. The inelastic shear distortion of the web is introduced by a non-linear pinched-type hysteresis at the element level.;The predicted response of the model is enhanced for the commonly observed "rocking" mechanism of shear walls at the foundation level. This is incorporated by a set of inelastic springs arranged in series with the reinforcing bars. These springs allow relative slippage of the bars from the underneath concrete structure.;Also included, are the effects of the connected structural elements such as spandrels, girders, transverse beams, and floor slabs in response of multistory shear wall structures. The bending, torsional, and shear resistance of these elements are incorporated by a series of separate external non-linear springs, attached to the model at the floor levels.;A series of comprehensive case studies are conducted to evaluate the analytical response predicted by the proposed model. The comparisons with the recorded experimental results are presented for all cases.