Material Properties - Non Linear Stress-Strain Relationship

Question:

Hello,

I have created a midas civil model for a Sydney Metro station,
For the analysis of a hydrocarbon fire, I need to Define the non-linear Stress Strain response for the elements subject to thermal loading,
This is to ensure that a plastic hinge forms, limiting the moment that each member is subject to,

In the attached excel spreadsheet I have plotted the Stress-Strain relationship,
Could you advise me, how do I include this stress-strain relationship within the Material properties?

Kind Regards,


Answer:
In order to consider the nonlinear stress-strain curve of material for the temperature loads, we should go for solid element model to which plastic material is assigned. Beam element cannot be used for this analysis. Once the solid element model is prepared, follow the steps below to perform the plastic analysis as follows:
1. Go to the Analysis>Analysis Control menu.
2. Select the 'Material Nonlinear' option.
3. Go to the Properties>Plastic>Plastic Material menu.
4. Define a material model using Tresca, von Mises, Mohr-Coulomb or Drucker-Prager.
5. Assign the plastic material to the corresponding solid elements.

Please note that there are some limitations in midas Civil
- Stress hardening of material can be considered but stress softening cannot be considered.
- Modulus of elasticity and thermal coefficient of concrete are changing along the temperature. This cannot be considered.

I don't know whether or not you have midas FEA. The above limitations are not there in midas FEA.
http://en.midasuser.com/product/fea_overview.asp

Regards,
DK Lee
Creation date: 6/7/2018 1:29 AM (dklee@midasit.com)      Updated: 6/7/2018 11:00 AM (dklee@midasit.com)
Files   
Material Properties - Non Linear Stress-Strain Relationship.xlsx
Thermal + %Gradient +Alpha.mcb