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I am trying to use the "Mooney-Rivlin von Mises Fibers" model to validate some results from this paper:
The geometry is sclera tissue which is a hemisphere (radius = 10 mm with thickness = 0.5 mm) and there is an optic nerve head (ONH) which is a small circle at the top of it (radius = 0.8 mm). Here is the geometry and mesh: P1.png
The paper says the nodes on the equator are constrained in all three directions. In addition the pressure load (45 mm-Hg) is applied on the internal surface of the shell:
P2.png
The material model assigned to the ONH is linear elastic (E = 0.3 MPa) and "von Mises Fibers" model is assigned to the sclera. The fibers in the sclera part are tangential to the sclera. I used cylindrical method to define the fibers.
<fiber type="cylindrical">
<center>0,0,0</center>
<axis>0,1,0</axis>
<vector>0,0,1</vector>
</fiber>
I put exactly the same values for the material parameters as mentioned in the paper (Section 2.5).
I want capture the Z displacement (in my model Z direction is switched with Y) of the top point of the model. Unfortunately the vertical displacement of the top point of the ONH is different from the value presented in the paper. In addition the deformed shape in FEBio simulation is different from the paper. Please see this figure:
P3.png
I have been struggling with this issue for a while. I also increased the mesh density but the results did not change. The geometry dimensions, material parameters, fiber orientation, load and boundary condition are exactly the same as the paper. I think I may miss something in applying the boundary condition or there may be a trick that I am missing.
I would appreciate your help to resolve this issue. The feb file is attached.
I am trying to use the "Mooney-Rivlin von Mises Fibers" model to validate some results from this paper:
The geometry is sclera tissue which is a hemisphere (radius = 10 mm with thickness = 0.5 mm) and there is an optic nerve head (ONH) which is a small circle at the top of it (radius = 0.8 mm). Here is the geometry and mesh: P1.png
The paper says the nodes on the equator are constrained in all three directions. In addition the pressure load (45 mm-Hg) is applied on the internal surface of the shell:
P2.png
The material model assigned to the ONH is linear elastic (E = 0.3 MPa) and "von Mises Fibers" model is assigned to the sclera. The fibers in the sclera part are tangential to the sclera. I used cylindrical method to define the fibers.
<fiber type="cylindrical">
<center>0,0,0</center>
<axis>0,1,0</axis>
<vector>0,0,1</vector>
</fiber>
I put exactly the same values for the material parameters as mentioned in the paper (Section 2.5).
I want capture the Z displacement (in my model Z direction is switched with Y) of the top point of the model. Unfortunately the vertical displacement of the top point of the ONH is different from the value presented in the paper. In addition the deformed shape in FEBio simulation is different from the paper. Please see this figure:
P3.png
I have been struggling with this issue for a while. I also increased the mesh density but the results did not change. The geometry dimensions, material parameters, fiber orientation, load and boundary condition are exactly the same as the paper. I think I may miss something in applying the boundary condition or there may be a trick that I am missing.
I would appreciate your help to resolve this issue. The feb file is attached.