Learning Forum

[to2020]

Hi,

I am doing a bond test with the rebar and concrete. When I apply 5mm of displacement on the rebar (over 200-300 substeps), I get the following result for the maximum principal stress:

[Rahul Kumbhar]

nJust to check have you turned ON large deflection in Analysis setting? What nonlinear material properties are you using for rebar?n

[to2020]

nThank you for the response. No, I haven't turned on the large deflection. nI just used the default material property given in ANSYS library for the structural steel (I then changed the tensile yield strength and ultimate tensile strength values to 500MPa and 560MPa respectively). I then did inputted bilinear law with yield strength of 500MPa and Tangent Modulus of 560MPa. I realised there was a typo in the value I inputted previously. But with the following updated settings: nStructural steel properties:nnConcrete Properties:nI then applied 5mm displacement on top of the rebar and the maximum principal stress I get is what is shown below:n

[Rahul Kumbhar]

nGreat! Please Turn ON the large deflection and try again.n

[to2020]

nSorry for the delay in getting back to you. nI was getting the following error, so I was increasing the substeps and still get this error:nnHere are my settings:nI am using 3mm mesh size. If you could please suggest what to do, it would be great.Thanks again! n

[to2020]

Array Could you please help or anyone who has an idea of what is causing the above error please reply n

[Ashish Khemka]

nnThe error above is element distotion error and the error message gives instructions on what to do:nExcessive distortion of elements is usually a symptom indicating the need for corrective action elsewhere.nTry incrementing the load more slowly (increase the number of substeps or decrease the time step size).nIn the Mesh task, change the setting for the Aggressive mechanical control that will create better aspect ratios. This approach is applicable only if you are using manual meshing.nConsider the behavior of materials and review the contact pairs.nPlease see if you can try implementing these changes.nnRegards,nAshish Khemkan

[to2020]

I have initially incremented the load between 200-300 steps. I have tried to increase this as per the recommendation but was getting the same error. nI haven't done manual meshing - just let the program create a mesh for me after specifying the contact sizing between rebar and concrete as well as the rib size (Both are set to 2mm because if I go any smaller, the program won't run as it exceeds the academic limit). nI have modelled the contact as friction (Between rebar and concrete). nIs there anything else I can do instead?Thanks!

[Ashish Khemka]

nnDid you check the element 78254 for which part is showing this error. Also, are you seeing this ina bilinear model with zero tangent modulus? If yes then you can expect this behavior as the material will behave as perfect plastic. Please let me know.nnRegards,nAshish Khemkan

[to2020]

nYes, it is a bilinear model. How can I check the individual elements? nThanks!n

[Ashish Khemka]

Hi Array ,nnInstead of bilinear model try using a multilinear model. For checking individual elements try using worksheet tab in the NAmed Selection:nnArraynFor motr details on plasticity model please refer to the link below:nnnFor motr details on plasticity model please refer to the link below:nnnRegards,nAshish Khemkan