Material

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

01 Defining Time-Dependent Material Properties

Settings

In this section it is to be determined which time-dependent effects are to be applied.

Creep

Check the 'Creep' check box if the time-dependent deformation of the material is to be taken into account when determining internal forces. You can then specify the parameters with which the program determines the creep coefficient φ:

• Relative humidity of the environment RH
• Concrete age at loading/introduction in system t₀

Shrinkage

This feature is still in preparation.

Modification of Concrete Curing

The following options are available in the list (see image image036724 Defining time-dependent material properties ):

• None: The concrete ages 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 on the button to define the parameters of the temperature treatment in a separate dialog.
• Measuring the 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 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 division of the graph.
• Concrete age at the point in time: The value t represents the end point of the abscissa.

Graph

In the lower right section you can see the ' Creep Index - 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 dialog ' Calculated time-dependent parameters '. There you can read off the creep parameters.

04 Calculated Time-Dependent Parameters

With the other buttons it is possible to adjust the representation of the diagram and to print the graphic.

Representation: linear or logarithmic

A linear (lin) and logarithmic (log) division of the axes is possible for an optimal display. The following options are available via 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 printing of graphics is described in chapter Graphics of the RFEM manual.

Import and export

The button enables the table values of a diagram to be imported from Excel. With the button you can export the creep coefficient - time diagram to Excel.