Material

In the Time-Dependent Properties tab of the Material dialog box, you can define the material properties relevant for the time-dependent analysis. In addition to the user-defined input for materials of the "Concrete" type, this can also be done according to the standard (EN 1992-1-1).

Settings

In this section, you have to specify which time-dependent effects are to be applied and which definition type is to be used. The input and the visualization change depending on the selection. For better clarity, the following distinction is made according to the selection of the definition type.

Definition type: User-defined

By selecting the 'User-defined' definition type, the function types Creep coefficient φ and Shrinkage strains ε_cs are available to you, corresponding to the selection of the applied time-dependent effects Creep and Shrinkage. These can be entered, inserted at the bottom left, or also imported from Excel using the button and exported using the button.

Define Time-Dependent Material Properties - User-Defined Definition Type

Graphic of time-dependent functions

In this section, you can specify parameters that are used for the visualization of the time-dependent functions. The function type selected in the Settings determines the time-dependent parameters displayed in the table and the Diagram. The following selection settings are available for the visualization:

• Number of Steps: The value n_s influences the division of the graph.
• Concrete Age at Considered Time: The value t represents the end point of the abscissa.

Definition type: According to Standard

For the 'According to Standard' definition type, the parameters of the time-dependent effects are calculated automatically according to the selected standard. Currently, determination according to "EN 1992-1-1" is available for concrete. For more information, see the manual of the Concrete Design add-on.

Specifying Time‑Dependent Material Properties According to Standard (EN 1992-1-1)

Creep

Select the 'Creep' check box if the time-dependent deformation of the material is to be considered in the determination of internal forces. You can then specify the parameters with which the program determines the creep coefficient φ:

• Relative ambient humidity RH
• Concrete age at loading / initiation in the system t₀

Shrinkage

Select the 'Shrinkage' check box if the time-dependent shrinkage strain is to be considered as a load. You can then specify the parameters with which the program determines the basic shrinkage coefficient ε_cd,0 and, from it, the shrinkage strains ε_cs, ε_ca, and ε_cd:

• Relative ambient humidity RH
• Concrete age at the end of curing t_s
• Concrete age at loading / initiation in the system t₀

Modification of Concrete Maturation

The following options are available for selection in the list (see image Defining time-dependent material properties according to standard):

• None: The concrete ages according to the standard curve.
• Temperature Treatment: The temperature treatment affects the curing of the concrete and thus the effective concrete age at loading. Click the button to specify the parameters of the temperature treatment in a separate dialog box.
• Measuring the Modulus of Elasticity: Enter the measured modulus of elasticity E_cm(t) and the time of measurement to consider an equivalent concrete age.
• Measuring the Concrete Strength: Enter the measured strength f_cm(t) and the time of measurement to consider an equivalent concrete age.

Graphic of time-dependent functions

In this section, you can specify parameters that are used for the visualization of the time-dependent functions:

• Function type: The function type determines the calculated time-dependent parameters displayed in the table and the Diagram. The following are available for selection:
  • Creep: Creep coefficient φ at the equivalent time
  • Shrinkage: Shrinkage strains ε_cs, ε_ca, and ε_cd
• Object Type: The object type for which the visualization is performed. The following are available for selection:
  • Thickness
  • Cross-section
• Number of Steps: The value n_s influences the division of the graph.
• Concrete Age at Considered Time: The value t represents the end point of the abscissa.

The button below the diagram opens the 'Calculated Time-Dependent Parameters' dialog box. There, you can read the creep and shrinkage parameters.

Calculated Time-Dependent Parameters

Diagram

In the lower right section, you see the 'Function Value - Time Diagram'. When you move the mouse along the graph, the respective abscissae and ordinates appear. You can zoom with the mouse wheel, move the diagram with the left mouse button, and restore the full view of the diagram by double-clicking the mouse wheel.

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

Representation: linear or logarithmic

For an optimal representation, a linear (lin) and logarithmic (log) division of the axes is possible. The following options are available for selection via the list button:

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

Print function

The diagram can also be printed. You have the following options via the list button:

• Print now
• To the printout report
• Print to PDF
• Copy to clipboard
• Print as file

Printing graphics is described in the Graphics chapter of the RFEM manual.

Export

You can use the button to export the time diagram to Excel.