I'm trying to model an RC column under different loading conditions (concentric and eccentric) using displacement controlled loading at a rate of 2mm/min and with a total displacement of 36mm, the column is strengthened by a hybrid technique of NSM CFRP strips not rods, and CFRP wrapping.
I'm not sure how to model the parts and the sections for the NSM CFRP and the CFRP wrapping, along with defining the material properties for both the NSM CFRP strip and the CFRP wrapping.
the datasheets for the CFRP used are attached below along with the created Abaqus model, could anyone guide me through the modeling of these parts..?!
Hey Naser, it is always good to start with a simple model in which you assume rigid connections between the materials and make that run smoothly. For CFRP I'd assume linear-elastic material behaviour until tensile strength and ultimate strain. Later, you can refine your model by including bond-slip laws for the CFRPs. In case of NSM, rigid connections are actually not completely wrong, considering the excellent bond properties. For the sheets you will have to find a fitting bond-slip law. Even sth simpler than a bi-linear law might do. If you check google scholar for "Finite element modeling of CFRP sheets bonded to concrete" you will find tons of literature. After that you can include a damage model for the concrete, maybe start with CDP before you get into something more complex. Hope this helps you, best regards, Bernhard
Bernhard Schranz
Hi Bernhard,
Thanks for your reply,
By rigid connections, you mean tie constraint..?
I did model the connections with tie constraints and now I'm trying a cohesive model for the contact between CFRP sheets and Concrete, for NSM I kept the contact as a tie constraint, is that correct..?!
I also included a CDP model while modeling the concrete material.
I hope you could advise me in regard to material orientation, I'm a bit lost in the application of the local coordinate orientation of the fibers of uni-direction fibers. Also, if you could advise me of what element type to use to model the NSM CFRP, I modeled it as solid elements (C3D8R), is that wrong..?
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