Modelling nonlinear concrete for SHELL181 elements

[Audy Maulizar]

Dear all,

I am wondering if there is a way for me to simulate nonlinear concrete behavior on SHELL181 elements. I am fully aware that SOLID65 is a better element to fully capture the nonlinear concrete behavior, but I would prefer for it to be SHELL181 to reduce computation resources and save analysis time. I have come across an investigation report by NIST on the WTC7 building that used MISO for the compression and mentioned that "slab elements that reached tensile or compression failure strains were softened". The report mentioned that this was done by replacing material properties of concrete with the one with a reduced elastic modulus. Is there a way to do this in Mechanical or maybe by using an APDL script?

[Giorgos Papa]

Hello Audy,

 

Thank you for your question.

 

Based on the ANSYS documentation, SHELL181 (and shell elements in general) does not support the Drucker–Prager (DP) or Menetrey–Willam (MW) concrete material models. These models are only available for 3D solid elements (e.g., SOLID185/186/187) or certain 2D planar elements, but not for shell elements.

 

You can find the full list of material models and the elements that support each one at the following link:

https://ansyshelp.ansys.com/public/account/secured?returnurl=/Views/Secured/corp/v252/en/ans_mat/Mp8sasdgh.html

 

You can also verify this by checking the element–material compatibility list here:

https://ansyshelp.ansys.com/public/account/secured?returnurl=//Views/Secured/corp/v252/en/ans_elem/elem_matsupp.html

 

Some alternative approaches for shell elements are the following:

1. If you want to use shell elements in AMAPDL You are limited to more generic nonlinear material models such as multilinear isotropic hardening plasticity (MISO), viscoplasticity, creep, and nonlinear elasticity. These can be defined using the TB family of commands, but they do not capture the complex failure and damage mechanisms typical of concrete.

 

2.If your workflow allows, LS-DYNA provides several concrete material models that are compatible with shell and beam elements, such as MAT_172, MAT_174, MAT_194, MAT_195, and MAT_209. These models can simulate damage, cracking, and nonlinear behavior in shell formulations.

 

Kind Regards,

Giorgos