Problem with Shear Stress of RC beams Simulations

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  • Last Post 08 May 2020
MakKimleang posted this 30 November 2019

Dear Sir/ Madam, 

I am doing a master's degree with a research topic of "strengthening the shear capacity of reinforcement beam with specific methods using shape memory alloys". Before I go through the method and using smart materials, I first try to simulate many normal reinforcement beams with explicit dynamics to see what type of shear failure of RC beam could occur when we use different of the stirrup, and it seems to have some problems with the data of shear stress of the beam.   

Geometry

Using line then create bars section to make the reinforcement in beam

Beam is 1100mm length x 150mm depth x 80mm width

Stirrup spacing 75mm 

Modeling 

Property:    -Normal Structural Steel

                   -Concrete 35MPa (Explicit Dynamics) 

Connection: -Body interaction (Fictional :Fictional Coefficent 0.1)

                     -Reinforcement 

Meshing: Body sizing 10mm 

Boundary condition: - Fixed displacement and roller displacement 

                                 - Loading: 120kN

Less Stirrup

These 3 images above are the first simulation with less stirrup. 

These 2 figures show the RC beam with full stirrup with the same boundary condition and meshing size. 

Problem: here is 2 examples of my simulation (one with full stirrup and another one with less stirrup) to identify the failure of shear to strengthen in the specific shear zone of RC beams 

1. 2 of simulations show a similar result of shear stress (I think the RC beam with less stirrup shall show the higher in shear stress than the RC beam with full stirrup) 

2. I simulate the RC beam with 4 point load bending test and, the failure of concrete seems to damage on the load area but not act like the diagonal failure of shear stress like other research paper have tested (is it because I did it wrong with the load or with the reaction?).

3. The stirrup inside the concrete beams separates apart like they are not connected with each other. (I think I have a problem with creating these stirrups in SpaceClaim geometry, so please give me some suggestion with that) .

Goals:

1. To find the shear stress failure in different uses of the stirrup in the reinforcement beams  

2. Identify the shear failure zone before using the material for strengthening in shear capacity. 

 

I hope you guys could help me with these problems and give me some suggestions with my Ansys simulation. I am looking forward to hearing from you, and please have a nice day! 

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  • biiahofmann
biiahofmann posted this 08 May 2020

Hello!

Im a civil engineering student and im doing my final project in ansys, but im having a similar problem with my analysis. Did you manage to find a solution?

Im a newbie in ansys, and I've been using it for only a few months, I paid a course but it only teached me the basics about it.

I decided to do my simulation in Explicit Dynamics because my beams have circular openings, so near the openings the mesh gets a different shape, so the stirrups dont get perfectly alligned with the concrete nodes, which made my life pretty hard on static structural since it needs both materials on the same nodes. 

I was wondering if anone could help me with my problem. I attached the images from my simulation, but the results are basically the same for the beam without the opening to the one with opening, which I know should be very different.

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