quadRC
3-D finite element model for planar RC elements
K. Kolozvari, CSU Fullerton
M.F. Gullu, Harran University
K. Orakcal, Bogazici University
quadRC element will be publicly available in OpenSees in fall 2021.
Description
The quadRC element (Figure 1b) is a three-dimensional four-node element with 24 DOFs for nonlinear analysis of planar reinforced concrete (RC) elements. The element in-plane behavior is described with two translational and one rotational (drilling) DOFs defined at each node of the element (Figure 1c) and is governed with a four-node bilinear finite element formulation (Figure 1d). The four in-plane DOFs that represent the drilling rotations normal to the plane of the element are presently implemented as “dummy” DOFs and are assigned infinitesimal stiffness values; i.e., the drilling DOFs are ignored in the present model element formulation. Material behavior at each integration point is described with the Fixed-Strut-Angle-Model (FSAM; Figure 1e). Out-of-plane behavior of the proposed model is simulated with a four-node elastic thin-plate finite element formulation based on the Mindlin-Reissner plate theory corresponding to one translational and two rotational DOFs (Figure 1f-g) at each node.
Figure 1. Model formulation: a) Wall segment, b) 3D four-node quadRC element, c) element in-plane DOFs, d) in-plane parent element, and e) 2D constitutive model for reinforced concrete (FSAM), f) element out-of-plane DOFs, g) plate moments
quadRC Input
element quadRC eleTag iNode jNode kNode lNode thick matTag <-thickMod tMod> <-Poisson Nu> <-Density Dens>
| parameter | description |
|---|---|
| eleTag | unique element tag |
| iNode jNode kNode lNode | tags of element nodes defined in counterclockwise direction |
| thick | element thicknesses |
| matTag | material tag of nDmaterial FSAM |
| tMod | thickness modifier for out-of-plane bending behavior (optional; default - 0.63, which is equivalent to 25% of uncracked stiffness) |
| Nu | Poisson ratio for out-of-plane bending (optional; default = 0.25) |
| Dens | Density (optional, default = 0.0) |
Recorders
In preparation
OpenSeesPy Documentation
In preparation
Example
In preparation
References
K. Kolozvari, M. F. Gullu, K. Orakcal (2021, in print). “Finite Element Modeling of Reinforced Concrete Walls under Uni- and Multi-directional Loading using OpenSees”, Bulletin of Earthquake Engineering.