Material

In the Time-Dependent Parameters tab of the Material dialog box, you can define the material properties that are relevant for the time-dependent analysis. This is currently only possible for concrete.

Defining Time-Dependent Material Properties

Settings

In this section, you can determine which time-dependent effects are to be applied.

Creep

Select the "Creep" check box to take into account the time-dependent deformation of the material when determining internal forces. You can then specify the parameters used to determine the creep coefficient φ:

• Relative humidity RH
• Age of concrete at loading / initiation in the structure t₀

Shrinkage

This feature is still in preparation.

Modification of Concrete Maturation

The following options are available in the list (see the image Defining Time-Dependent Material Properties):

• None: The concrete matures according to the standard curve.
• Temperature treatment: The temperature treatment has an effect on the hardening of the concrete and thus on the effective concrete age under load. Click the button to define the parameters of the temperature treatment in a separate dialog box.
• Measuring of Modulus of Elasticity: Enter the measured modulus of elasticity E_cm(t) and the time of measurement in order to take into account an equivalent concrete age.
• Measuring of Concrete Strength: Enter the measured strength f_cm(t) and the time of measurement to take into account an equivalent concrete age.

Function Data (Only for Visualization)

In this section, you can define parameters that are used for the visualization of the creep coefficient – time diagram:

• Number of Steps: The value n_s influences the graph division.
• Age of concrete at the considered time: The value t represents the end point of the abscissa.

Diagram

In the lower right section, you can see the "Creep Coefficient – Time Diagram". If you move the mouse along the graph, the respective abscissas and ordinates appear. Use the mouse wheel to zoom, use the left mouse button to move the diagram, and double-click the mouse wheel to restore the overall view of the diagram.

The button below the diagram opens the "Calculated Time-Dependent Parameters" dialog box. You can read off the creep parameters there.

Calculated Time-Dependent Parameters

The other buttons allow you to adjust the display of the diagram and to print the graphic.

Display: Linear or Logarithmic

A linear (lin) and logarithmic (log) division of the axes is possible for an optimal display. The following options are available using the list button :

• lin X / lin Y
• log X / lin Y
• lin X / log Y
• log X / log Y

Print Function

It is also possible to print the diagram. Using the list button , you have the following options:

• Print Graphics to Printer
• Print Graphics to Printout Report
• Print Graphics to PDF
• Print Graphics to Clipboard
• Print Graphics to File

The graphics printout is described in the chapter Graphics of the RFEM manual.

Import and Export

The button allows you to import the table values of a diagram from Excel. Use the button to export the Creep Coefficient – Time Diagram to Excel.