Topic: Modelling Bolt Connection in Reinforced Concrete Slab


I am modelling reinforced concrete slab supported at four-corners on steel plates (200x200 mm). Steel plate is connected with the slab through M20 bolt. To connect the bolt a special assembly has been placed inside concrete during casting.

I modeled the bolt using vertical spring at joint (at exact location of bolt) with z-direction fixed. I have applied boundary conditions on the steel plate with x and y-directions fixed.

The model ran, but I found the deflection is too low and slab failed much before the yielding of tensile steel.

My understanding, I could not model the bolt connections.

My questions:

1. Do I need to build a physical bolt as a macro element (ABAQUS has this option)? If yes, how and what should be its material model?
2. Instead of using physical bolt what other options I have?

I can send the model for your review.


Re: Modelling Bolt Connection in Reinforced Concrete Slab

Dear Ahsan,
I. please follow ATENA Troubleshooting, 2.1.1 to send us your model etc.

II. It is not clear from your description what kind of supports are applied in reality - please send sketches/photos along with a description.

III. If I understand correctly, the bolts pass through the concrete - connecting the support plate with some other plate(s) on the other concrete surface. If so, I don't understand how you planned to represent the bolt with a spring support?
The simplest and most common modelling of such a bolt is a 1-D reinforcement bar.