Regarding the Pull-out test of concrete-steel rebar

[Chamil Dhanasekara]

Hi all, 

I am trying to simulate the pull out test of concrete-rebar bond slip behavior in LS-Dyna. Here I have used the Beam In Solid keyword and i defined the function for bond slip model. When i am going to run the model, it took only few seconds and message is given as  ''Nonlinear solver failed to find equilibrium''. Is any one expert in pull out test simulation in LS Dyna, I need your help.

Here I attached my k file as well.

Thanks.

Chamil.

[James M. Kennedy]

Dear Chamil,

 

Rabczuk, T., Akkermann, J., and Eibl, J., "A Numerical Model for Reinforced Concrete Structures", International Journal of Solids and Structures, Vol. 42, Issues 5-6, pp. 1327–1354, March, 2005.

 

This paper describes a two-dimensional approach to model fracture of reinforced concrete structures under (increasing) static loading conditions. The first part is dedicated to the concrete material. The concrete is described in compression by a non-local isotropic damage constitutive law. In tension, a fictitious crack/crack band model is proposed. The influence of biaxial stress states is incorporated in the constitutive relations. In the second part a bond model is described. It accounts for different failure mechanisms, a pullout failure and a splitting failure. This approach is applied to prestressed concrete beams with different failure mechanisms. The numerical results are compared to experimental data and show good agreement.

 

http://www.sciencedirect.com/science/article/pii/S0020768304004366

 

https://www.researchgate.net/post/How_to_calculate_CONTACT_1D_parameters_in_LSDYNA_for_Rebars_bond-slip
 
A one-dimensional slide line contact model in LS-DYNA for modeling sliding of rebar along a string of concrete nodes was used to model the bond slip between concrete and steel bars in RC structures. In order to model the bond slip accurately, a new approach to define the parameters of the one-dimensional slide line model from common pullout test data was proposed:
 
Shi, Y., Li, Z,-X., and Hao, H., "Bond Slip Modelling and its Effects on Numerical Analysis of Blast-Induced Responses of RC Columns", Structural Engineering and Mechanics, Vol. 32, No. 2, 2009
 
https://espace.curtin.edu.au/handle/20.500.11937/34742

This paper presented a study on the bond behaviour of FRP-concrete bonded joints under static and dynamic loadings, by developing a meso-scale finite element model using the K&C concrete damage model (*MAT_072R3) in LS-DYNA. A significant number of single shear experiments under static pull-off loading were modelled with an extensive parametric study covering key factors in the *MAT_072R3 model, including the crack band width, the compressive fracture energy and the shear dilatation factor. It was demonstrated that the developed model can satisfactorily simulate the static debonding behaviour, in terms of mesh objectivity, the load-carrying capacity and the local bond-slip behaviour, provided that proper consideration is given to the selection of crack band width and shear dilatation factor:

 

Li, X., Chen, J.-F., Lu, Y, and Yang, Z., "Modelling Static and Dynamic FRP-Concrete Bond Behaviour Using a Local Concrete Damage Model", Advances in Structural Engineering, Vol. 18, No. 1, pp. 45-58, January, 2015.

 

https://pure.qub.ac.uk/portal/files/17002437/04._Chen_authors_copy.pdf

 

In order to simulate the pull-out forces of a screw, the finite element method was employed, simulation models from three different material models selected from the Finite Element Analysis (FEA) software LS-DYNA. The first material model considered Mat_143, a wood material model based on the Hashin failure criterion and used to develop simulation model 1. The second material considered, *MAT_122 3D, based on Hill’s plasticity theory, was used with *MAT_ADD_GENERLIZED_ DAMAGE to allow for incremental damage accumulation and failure. This was simulation model 2. The third one, Mat_221 which represents an orthotropic material with simplified damage, was used to develop simulation model 3

 

Phiri, T., and Bjorkman, N., “Simulating Pull-Out Fracture in Particleboard”, Master’s Thesis, Department of Mechanical Engineering, Linkoping University, Linkoping, Sweden, Spring, 2019.

 

http://liu.diva-portal.org/smash/get/diva2:1413908/FULLTEXT01.pdf

 

A simple example of 1D contact that verifies the theory (a brief discussion of the theory is given in the text file contact.1d).

http://ftp.lstc.com/anonymous/outgoing/jday/concrete/pullbar.k

 

Some further details are provided here for 1D contact:

http://ftp.lstc.com/anonymous/outgoing/jday/concrete/contact.1d

 

Sincerely,

James M. Kennedy

KBS2 Inc.

August 8, 2022

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[l...@schwer.net]

I suggest you first get your model to work with the explicit solver, before trying to use the implicit solver.                               --len

 

From: ls-d...@googlegroups.com <ls-d...@googlegroups.com> On Behalf Of Chamil Dhanasekara
Sent: Monday, August 8, 2022 10:45 AM
To: LS-DYNA2 <ls-d...@googlegroups.com>
Subject: [LS-DYNA2] Regarding the Pull-out test of concrete-steel rebar

 

Hi all, 

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