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How to decide proper mesh size and avoid strain localization in elements?

Hello, i am basically modelling a notched tensile specimen in 1/4 symmetry. In this part of my project i have two main problems.
 
1) When i apply force to model, it only deforms first row of the elements. Which is causing inconsistent results. As you can see in the figures, equivalent plastic strain values of finer meshed model is almost twice the value of coarser meshed model. Hence, i am looking for a way to create a model which would yield a homogeneous strain field rather than a strain field localized in only a single element row.
 
2) Again, as u can see from the figures strain behavior of the material under same circumstances are completely different from each other. In this case, how can i verify my results, which mesh size should i select to get more trustworthy results, would converting my elements into a tri (3) element type help? How can i avoid high shape distortion in the elements?
 
Any answer, advice or source is appreciated. Thank you in advance!

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  • Hi Kiranraj.Shetty,
    Strain gradient is high because of the localization, and it becomes higher when i refine the mesh. Unfortunately i can not use local remeshing because i need the nodal values after the simulation which i can not reach if i use local refinement. When i use finer mesh, elemental distortion increases hence results become inconsistent. As an example, finer mesh figure above, elements are clearly more distorted in the fine mesh. Hence, i need a solution for stress and strain concentration in only single row of elements. Instead, i want a way to distrubute to strain in a field no matter how much the mesh is fine.
     
    Thank you for your answer.
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  • Hi Kiranraj.Shetty,
    Strain gradient is high because of the localization, and it becomes higher when i refine the mesh. Unfortunately i can not use local remeshing because i need the nodal values after the simulation which i can not reach if i use local refinement. When i use finer mesh, elemental distortion increases hence results become inconsistent. As an example, finer mesh figure above, elements are clearly more distorted in the fine mesh. Hence, i need a solution for stress and strain concentration in only single row of elements. Instead, i want a way to distrubute to strain in a field no matter how much the mesh is fine.
     
    Thank you for your answer.
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