{"id":358943,"date":"2024-03-26T06:07:09","date_gmt":"2024-03-26T06:07:09","guid":{"rendered":"\/forum\/forums\/topic\/inaccurate-stress-values-menetrey-willam-concrete\/"},"modified":"2024-03-26T06:21:08","modified_gmt":"2024-03-26T06:21:08","slug":"inaccurate-stress-values-menetrey-willam-concrete","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/inaccurate-stress-values-menetrey-willam-concrete\/","title":{"rendered":"Inaccurate Stress values – Menetrey Willam Concrete"},"content":{"rendered":"

Hi! I am currently modelling an RC Beam subjected to 4 point bending test for my thesis. Here are the following details:<\/p>\n

<\/a><\/p>\n

Symmetry Region – (quarter beam)<\/p>\n

Boundary Conditions<\/p>\n

<\/a><\/a><\/a><\/p>\n

Input parameters for Menetrey Willam concrete<\/p>\n

<\/a><\/p>\n

Input parameters for Steel<\/p>\n

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The parameters are all from related literature. <\/p>\n

Command snippet at Concrete body<\/strong><\/p>\n

TB,CONCR,matid,,,MSOL
TBDATA,1,2,1,1e-3,100,10,1e-20<\/p>\n

My reference study shows that the beam should fail at 35 mm. However, my model still does not fail at 70+ mm. My criteria for failure is (1) <\/strong>Steel yielding or von mises stress of steel reaching 400 MPa and (2)<\/strong> Von mises stress of compressive face of concrete reaches 40 MPa. My problem is that even though my model converges, the von mises stress of concrete is only ~30 MPa at 60 mm which causes overestimation of midspan deflection. <\/p>\n

(1) Steel yields at 400 MPa <\/p>\n

<\/p>\n

(2) Concrete Compressive edge (critical location since midspan) still does not reach 40 MPa at 60 mm <\/p>\n

<\/p>\n

 <\/p>\n

1) What can I do to fix this? Is there something wrong with my boundary conditions, input parameters, etc.? <\/p>\n

2) Would you recommend for me to use a different material model? I was wondering if I should just use Multilinear isotropic model for concrete with a solid65 element type but I am not sure if that can successfully model the softening behavior of concrete. I am also thinking if I should use Drucker Prager instead. <\/p>\n

3) Does anyone know what the command snippet above does? When I remove it, the model does not converge. However, I do not know what the values indicate. <\/p>\n

4.) Should I add another model for concrete that takes into account damage? To my understanding, Menetrey Willam is only a plasticity model so it does not sufficiently model post peak behavior (am I right?). Will doing this correct my problem on concrete compressive stress?<\/p>\n

5.)  I will be modelling Fiber sheets afterwards. How can I set an ultimate strain for fiber sheets such that it fractures at that strain value? <\/p>\n

I would really appreciate any help. Thank you very much!<\/p>\n

 <\/p>\n","protected":false},"template":"","class_list":["post-358943","topic","type-topic","status-closed","hentry","topic-tag-menetrey-william","topic-tag-rc-beam","topic-tag-reinforced-concrete","topic-tag-thesis-help-1","topic-tag-three-point-bending-test"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t