• JGS
  • New member
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  • Registered: 2019-07-03
  • Posts: 1

Topic: Multiple Bond Models for 1D Reinforcement Connected in Series

Hello,

My name is Jeff, and I am trying to model bond-slip for smooth reinforcing bars. I would like to model a straight bar segment connected to a 180-degree hooked anchor (i.e. two bond models for the same reinforcing bar). Research by Fabbrocino et al. (2004 and 2005) have shown both to be significant in older RC structures.

I’ve read some previous posts related to this subject. One post from 2013 by Francesco who was attempting to model two bars in series but found that the 1D truss elements were not directly connected but were connected only through a transfer of forces with the surrounding concrete elements.

Another post by njoukhadar in 2019 appeared to be attempting something similar, but the final solution wasn’t clear. The user may have sent in his/her model and received additional help, but this was not posted in the forum.

I have attempted to model two 1D reinforcement bars in series: (1) having low bond quality and (2) with the bond properties associated with a hooked anchor. The force transfer and damage to the surrounding concrete suggests that the bars are not attached together. I was wondering if there is a solution for this such that I can connect the two bars in series with different bond models? Your help would be greatly appreciated.

Kind Regards,
Jeff

Quote Post 1

  • dpryl
  • CC software developer
  • Offline
  • Registered: 2007-07-13
  • Posts: 1,107

Re: Multiple Bond Models for 1D Reinforcement Connected in Series

Dear Jeff,
I assume you have already read ATENA Troubleshooting, 2.2.12.3 Unbonded segments.

I guess the simple approximation with perfectly bonded hook as 1 bar + the rest as a 2nd bar with the corresponding bond law (with "no slip" at the end connected to the hook part) has also shown as not good enough?

You can send us some sketches + description (Troubleshooting, 2.1.1) such that we can try to find a good way of modelling for you.

Regards.

dpryl's Website

Quote Post 2

  • From: Finland
  • Registered: 2019-03-28
  • Posts: 138

Re: Multiple Bond Models for 1D Reinforcement Connected in Series

Hi Jeff,

Which program do you use? (Atena 2D, 3D, Science). I have just tried one bar of 2 segments, one with perfect connections, another with bond and found there is no problem. You can see it on the linked pictures:
https://drive.google.com/open?id=19ZQHC … y99y_fKmlr

Quote Post 3

  • Registered: 2021-01-25
  • Posts: 3

Re: Multiple Bond Models for 1D Reinforcement Connected in Series

hello
Can I define the corrosion bonding slip of different sections of 1D steel bar
That is, the bond slip of the one bar that wants to corrode the bar, the bond slip of the ribbed bar
Why not, is there a simple way to solve this problem

Quote Post 4

  • From: Finland
  • Registered: 2019-03-28
  • Posts: 138

Re: Multiple Bond Models for 1D Reinforcement Connected in Series

Basically you can divide a rebar into as many parts as you want and assign different reinforcement properties to each one (and you decide yourself whether you vary only bond slip or other properties as well).
However, these settings are set in preprocessor and cannot be varied based on a current step analysis results (maybe you need this, I couldn't clearly understand your intention).
If you give a link to a sketch with your problem description it would be much easier to answer exactly.

Quote Post 5

  • Registered: 2021-01-25
  • Posts: 3

Re: Multiple Bond Models for 1D Reinforcement Connected in Series

Okay, thank you. Best wishes

Quote Post 6