NEHRP Clearinghouse

Title
Contribution of a Floor System to the Dynamic Characteristics of Reinforced Concrete Buildings.
File
PB272247.pdf
Author(s)
Malik, L. R.; Bertero, V. V.
Source
National Science Foundation, Washington, D.C., December 1976, 292 p.
Identifying Number(s)
EERC-76-30
Abstract
A practicable and sufficiently accurate stiffness matrix method for estimating the contribution of a floor system to the overall elastic stiffness of moment-resisting space frames is developed. The floor system considered consisted of a two-way reinforced concrete slab supported on beams between columns. This stiffness matrix method is achieved by performing extensive parametric finite element analyses to identify the main parameters affecting and, therefore, controlling the stiffness of individual floor panels of the floor system. The stiffness of a two-way slab floor panel has been investigated by establishing an 8 x 8 panel stiffness matrix based on two rotational degrees of freedom (DOF) at each panel support. Stiffness matrix elements are determined by computing the moments necessary to produce a unit rotation at one support DOF while restraining the other seven DOF in the panel. Existing finite element computer programs are used in these computations. A series of rectangular finite elements models the bending and membrane stress-strain relations of the floor slab. The beams are modeled as uniaxial, prismatic members, connected by rigid links to the slab finite element nodes along the beam's centerline. Analytical tests confirm this method's accuracy in estimating the beam-slab composite action in flexible floors.
Keywords
Floors; Dynamic response; Buildings; Earthquake engineering; Earthquakes; Reinforced concrete; Finite element analysis; Concrete construction; Computer aided analysis; Stiffness methods