Nonlinear Concrete Creep

Question:

Hi,

Hope you're doing fine. Would like to know if it is possible to model in nonlinear concrete creep coefficient to the model based on BS EN 1992-1-1 Clause 3.1.4 (4)? (see attached).

How we can export verify the final nonlinear concrete creep coefficient in the model? 

Hope to hear from you.

Thank you,
MJ

Answer:

Hello,
We cannot consider nonlinear creep coefficient variation based on EN 1992-1-1 code directly in Midas if we consider Creep variation based on codes.
However, we can create user defined Creep function using Properties > Time Dependent Material > User Define


Then, in the Properties > Creep / Shrinkage tab, add the defined coefficient:


However, there is one restraint. 
For user-defined creep to accurately calculate creep effects at least 15 functions need to be defined for different ages of loading. Only then does the software takes the value of the creep coefficient correctly and also interpolates accordingly.

First minimum 15 functions for different loading would be defined : 
Sample below:


Then these function would be linked to creep/shrinkage properties. 

We have attached a small file for your reference.
Note that it is just a sample for Creep user defined function and the values mentioned are not to be taken at face value.


Regards,
Rohan Agarwal
Structural Engineer

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Creation date: 3/22/2022 12:58 PM      Updated: 3/24/2022 6:11 AM
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DataImage46.png
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DataImage57.png
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EC2 Clause 3.1.4(4) Nonlinear Creep Coefficient.PNG
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I beam-CEB-user_2 cases - Copy.mcb
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