Modeling of R/C Building Structures With Flexible Floor Diaphragms (IDARC2)

Keywords: Computer Codes, Damage Analysis, Dynamic Response Analysis, Flexible Diaphragms, Floors, Hysteresis Models, Reinforced Concrete, Sequential Failure Mode Analysis, Static Analysis, Shaking Table Tests, and Seismic Response.

Abstract: An analytical modeling scheme has been developed to include the effects of inelastic in-plane diaphragm flexibility in the analysis of reinforced concrete building structures. The floor-slab model has been incorporated into the existing framework of a computer code for Inelastic Damage Analysis of Reinforced Concrete frame shear-wall structures, IDARC. The revised computer code (IDARC2) has been used in parametric and correlation studies primarily to design a shaking table study of a single story 1:6 scale micro-concrete model. The results of the preliminary analytical studies indicate that the in-plane floor flexbility can be a dominant factor on seismic response (i.e., overall dynamic characteristics and lateral force distribution) for rectangular shear-wall-frame buildings. The inplane deflections of the floor diaphragms impose larger strength and ductility demands on the columns of the flexible frames than is usually provided in such columns. The assumption of rigid floor diaphragms results in a non-conservative design of flexible frames. This can cause severe damage in these frames which eventually can lead to loss of vertical load carrying capacity of the columns with disastrous consequences. A user guide for the revised computer program is included to enable use of this program for other applications.