Time Dependent Material (Creep/Shrinkage) Function
The user directly defines the time dependent material properties (creep & shrinkage) of concrete. The properties are applied to Construction stage analysis and Heat of hydration analysis.
Select User Defined as the Code in the Add/Modify Time Dependent Material (Creep/Shrinkage) dialog box and select the Creep Function and Shrinkage Strain Function defined here.
From the Main Menu select Model > Properties > Time Dependent Material (Creep/Shrinkage) Function.
Select Geometry > Properties > Time Dependent Material (Creep/Shrinkage) in the Menu tab of the Tree Menu.
Time Dependent Material Function dialog box
Click 
under the tab being considered for data entry.
Click 
to check or change or click 
to delete the entered data. Click
to copy previously entered data.
Creep tab
dialog box for Add/Modify/Show Time Dependent Material Function
Define the time dependent creep property of concrete material.
Function Name: Enter the name of Creep Function, which is referred to in the Add/Modify Time Dependent Material (Creep/ Shrinkage) dialog box if User Defined is selected in the Code field.
Creep Function Data Type
Select one of the Creep Function Data Types.
Specific Creep: Strain per unit stress excluding immediate deformation
Creep Function: Strain per unit stress including immediate deformation
Creep Coefficient: Ratio of creep strain to elastic strain ( 
)
Elasticity
Enter the modulus of elasticity of concrete.
midas uses Specific Creep for creep analysis. For more details, refer to Time Dependent Analysis Features > Time Dependent Material Properties in the "Analysis Manual"
A frequently used Creep Function may be saved in and recalled from a file. The data file, fn.TDM retains the following form:
|
* Unit, kip, in |
Assign the units (optional items) |
|
20, 0.9934 |
Enter the data in the form of 'day' and 'value' (mandatory items) |
|
40,1.2182 |
- |
|
60, 1.3705 |
- |
|
80,1.4883 |
- |
|
100, 1.5854 |
- |
|
120, 1.6683 |
- |
|
140, 1.7408 |
- |
|
160, 1.8054 |
- |
|
180, 1.8636 |
- |
|
200, 1.9166 |
- |
|
220, 1.9653 |
- |
|
240, 2.0103 |
- |
|
260, 2.0252 |
- |
Scale Factor: Multiplier for values
Graph Options: Check on for Log Scale graph
Description: Descriptive text for the Function
Shrinkage Strain tab
Define the shrinkage strain, which is a function of time.
Function Name: Enter the name of the function defining the change of creep strains, which is referred to in Shrinkage Strain Function of Add/Modify Time Dependent Material (Creep/ Shrinkage) dialog box when the Code is User Defined.
A frequently used Shrinkage Strain Function may be saved in and recalled from a file, whose type is fn.TDM as for the Creep tab.
Scale Factor: Multiplier for values
Graph Options: Check on for Log Scale graph
Description: Descriptive text for the Function