Module "Stiffness matrix"

Module Stiffness matrix

The cross section can be defined by the user or by choosing a typical cross section of a proprietary CLT product. There is also the possibility to save own CLT cross sections in a library. The elements are subdivided by the number of layers.

If a user-defined cross section is entered, the thickness and orientation of each layer can be changed. Furthermore, the material can be changed for all layers. The thickness of each layer has to be within the range of 6.0 mm to 45 mm. In the case of proprietary CLT products, the strength class of lumber and the orientation can be changed. If the orientation is changed, the whole cross section is rotated.

Input - Cross section

The width of the CLT plate strips can be also defined in this field. The default value is set to 1 m. The thickness of the CLT plate is calculated automatically based on the thickness of the single layers.

The ratio of board thickness to board width can also be changed here. The default setting is 1:4.

My CLT cross sections

By clicking the button the current cross section can be stored in the library and be retrieved by selecting "My CLT cross sections" later on.

The library can be displayed with the button .

Library "My CLT cross sections"

  • The edit mode can be entered by clicking on . Currently, only the name of the stored cross section can be changed.
  • With the changes are saved.
  • With the chosen cross section in the sidebar can be removed from the library.
  • With cross sections from a csv file can be imported.
  • With the cross sections from the library can be exported to a csv file.

Syntax of the csv file

name;number of layers n;layer thickness in [m] t1 to tn;orientation of the layers o1 to on (0 or 90);name of material

Test layup;5;0.03;0.02;0.02;0.02;0.03;90;0;90;0;90;GL24h*

My materials

With the button the material library can be displayed.

Library "My materials"

  • With the edit mode can be entered.
  • With the changes are saved.
  • With the chosen material in the sidebar can be removed from the library.
  • With materials from a csv file can be imported.
  • With the materials from the library can be exported to a csv file.

Syntax of the csv file

1. row: description of the parameters
2. row: units of the parameters
3. row: value
delimiter: ";"

Mat 1;24;16.5;0.5;24;2.7;3;1.25;11600;9667;0;720;72;380;500;5.5;2.5;21

The user-defined materials are then displayed in the material selection list.

material selection list

Optimization of layup

Use the button to display the window for layup optimization.

Layup optimization

With the help of this tool, the possible layups can be determined for the given system and load situation. The optimization can be restricted with regard to producers, number of layers or by means of limits for the panel thickness. Furthermore, outer cross layers or double layers can be included or excluded. With the option "Vibration verification according to EN" the base document is included in the vibration check or not.

With the buttons "Start" and "Stop" the calculation is controlled. Please be patient, depending on the selected parameter the calculation may take a little longer.

The possible setups are then displayed in the table and the selected setup can be transferred to the main window by clicking the "Choose the selected cross section" button.

· 2017/11/14 17:11

Bending and torsion

Stiffness matrix - Parts for bending and torsion

Shear for CLT-plate loaded out-of-plane

Stiffness matrix - Parts for shear out-of-plane

In-plane Stiffness values

Stiffness matrix - Parts for loading in-plane (membrane)

Eccentric effects

Stiffness matrix - Consideration of eccentricity

By clicking on the button a csv file will be created, which contains the input data for RFEM 5.

Contents of the csv file

The csv file can be imported into RFEM 5 via "Edit Surface" and the tab "Stiffness Matrix".

RFEM 5 - Edit Surface

RFEM 5 - orthotropic stiffness matrix

  • en/clt/hotspot/software/cltdesigner/manual/modul_stiffness_matrix.txt
  • Last modified: 2020/03/26 11:46
  • by Alexandra Thiel