I am working on a hyperelastic simulation in ANSYS workbench, refer attached pictures for details. The problem is confined to 2D. The right geometry is an elastomer (defined by Yeoh's model). The left one is fixed and is Aluminium. The elastomer should be supplied high pressure (~7 or 8 bars). upon its expansion, it will make contact with the Aluminium surface and i need to look at the contact pressure.
I am getting error message as shown, I refined the mesh, see mesh quality attached. Also I increased pressure very slow. The sub-steps are large enough. Can anyone troubleshoot the problem?
Hi Yang,
The pressure that I want to apply is 7 bars (0.7 MPa). As I can't apply that in one single step. I splitted that in 5 steps. Look at the error, it suggest increment load slowly that is why I am incrementing it slowly, but it is of not much help unfortunately.
Hi Yang,
Thank you for the response. Alright I will try that. But why elements become so distorted even when the mesh is not so bad? and how to fix that distortion actually?
Hi Tarif,
I am using triangular elements. I am using ANSYS workbench, not APDL. From where I can see this number?
Looking at the result I would say that the element type is not capturing the type of behaviour you are looking for. Here you have link roughly explaining how you can set up the ET in workbench,
http://www.eng-tips.com/viewthread.cfm?qid=319460
Hi Pablo,
Thank you for the link. The elements are getting distorted in the lower curvature region. In general, how to solve distortion other than sizing the mesh?
Well, when the simulation retrieves data like these you usually look at the size of the elements of your mesh. You might also be getting that answer because of the material behaviour. It can be warping because the part you are looking at is not stiff enough (check dimensions, Young's modulus..). Also it is worth looking at the constraints. When you say that the part is fixed, does it mean that the vertical and horizontal edges are fully constrained or only the vertical one? The type of element you use is key. According to the scale it seems that it is a very thin part so I would recommend you to use a Shell281 or similar. Check in the ANSYS help file for its characteristics. Ultimately, some elements distort a lot when they are splitting up sharp edges. In that case, you should go for a detailed mesh control. Maybe by having larger elements that you can split up later on again until you get the desire value in the independence study
hi dear
you should use suitable mesh, size and shape is important, triangle shape mey be better for you, could you send me an invitation to denmark??
I am also working on a hyperelastic simulation in ANSYS workbench. Use linear tetrahedrons mesh (with drop option for element midside nodes) for hyperelastic structure, it is the best in term of convergence and element distortion.
Hi Ammar,
Thanks for the answer, in element method, I only see Triangles or Quadrilateral. From where I can select tetrahedron mesh? Refer file attached.
Prateex,
I am sorry, I forgot that your simulation is in 2D, while tetrahedron is for 3D model. Just use triangles, with drop option for element midside nodes.
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