Contacts & APDL RC Concrete
I'm currently trying to carry out analysis on confinement in concrete columns. It is a simple concept of concentrically loaded columns and I am essentially loading until failure. The models tend to look like the image below.
I have attempted to model the concrete using SOLID65 and the steel rebar as LINK180 using line bodies and defining them as link truss elements in mechanical. The rebar has been modelled discretely and I have attempted to define the contact between the two materials by ensuring the mesh of both materials are coincident and using a CEINTF command.
The results seem reasonable however they become less accurate as I increase the amount of steel links (i.e. confinement). The models seem to underestimate the confinement. Also I have found in some cases, the steel links in models of high confinement don't reach yield which I would assume unusual.
Is the use of the Ceintf command + Link 180 elements suitable for modelling the brittle failure in this case?
I have defined the concrete stress strain behavior through APDL and also failure as shown below. I avoided providing the uniaxial compressive stress as I got poor results from even the most simple of concrete structures.
I'm just trying to understand what is happening in the ANSYS model. Any insight would be much appreciated, thank you.