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Module "Compression perpendicular to grain"

Module Compression perpendicular to grain

The input is divided into:

  • definitions of the cross section
  • definitions of the plate dimensions
  • input of the loads
  • type of load configuration
  • calculation options


An option for a quick control of the input data is offered by a graphical representation shown on the right side.

Cross section, plate dimensions and load configuration


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

Plate dimensions and gap execution


The plate is specified with its dimensions in x and y direction. The plate length is defined with dimension in x direction and the plate width with dimension in y direction.

Die Platte wird durch ihre Dimensionen in x- und y-Richtung beschrieben. Die Länge der Platte ist die Abmessung in x-Richtung und die Breite die in y-Richtung.

Input - Plate dimensions and gap execution


In addition to plate dimensions, the analysis also considers the way the lamellas are joined into individual layers. In this regard, when it comes to outer layers, one should differ:

  • side gluing of lamellas,
  • assembly without adhesive where lamellas are placed side by side without the sheduled gaps or the expected occurence of cracks and
  • possible occurence of gaps or cracks wider than 1 mm.

Neben der Plattenabmessungen geht auch die Fugenausführung in die Berechnung ein. Bezüglich der Fugenausführung ist zu unterscheiden ob die Decklagen

  • seitenverklebt sind,
  • nicht seitenverklebt, aber Mann an Mann (ohne planmäßige Fugen) bzw. ob Risse zu erwarten sind und
  • ob Fugen oder Risse mit größer 1 mm auftreten können.

Load data and design factors


The applied force Fc,90 (design value) in [N], as well as the design factors can be specified here.

Hier können die einzuleitende Kraft Fc,90 (Bemessungswert) in [N] sowie die Bemessungsfaktoren angegeben werden.

Input - load data and design factors

Load configuration


The load situation is described by specifying the load introduction above and below. Thereby, one can define if the load is even applied, and if so, if it is applied locally or continuously (over entire surface).

If the load is applied locally, it needs to be defined by entering the dimensions of the load surface (length l1,2 in direction x and width w1,2 in direction y) and the position. The position is defined as the distance between the center of a load surface and the origin of the coordinate system (lower left corner of the plate). Currently, centers of the top and the bottom load surface are coupled and cannot be moved relative to each other.

Die Lastsituation wird durch die Lasteinleitung oben und unten beschrieben. Dabei kann die Lasteinleitung lokal oder kontinuierlich (über gesamte Plattenfläche) erfolgen oder auch keine Lasteinleitung vorhanden sein.

Bei lokaler Lasteinleitung sind die Abmessungen der Beanspruchungsfläche (Länge in x-Richtung l1,2 und Breite in y-Richtung w1,2) sowie die Lage einzugeben. Die Lage wird durch den Abstand des Mittelpunktes der Beanspruchungsfläche zum Koordinatenursprung (Eckpunkt der Platte links unten) beschrieben. Derzeit sind die Mittelpunkte der Beanspruchungsflächen oben und unten gekoppelt und können nicht gegeneinander verschoben werden.

Input - load configuration

Calculation options

In den Berechnungsoptionen können die Lastausbreitungswinkel für Längslagen α0 und für Querlagen α90 verändert werden sowie bei einseitiger Lasteinleitung kann angegeben werden, in welcher Höhe (= kls ⋅ tCLT) die effektive Fläche bestimmt werden soll.

Input - calculation options

Die minimale Lasteinleitungsfläche beschreibt die Bezugsfläche, um mit dem Querdruckbeiwert kc,90 auf die effektive Fläche Aef,max zu kommen. Bei unterschiedlichen Beanspruchungsflächen oben und unten ist es die Überschneidungsfläche der beiden Beanspruchungsflächen. Die effektive Fläche Aef,max wird durch lef und wef in der Höhe z beschrieben.

Die Ausnutzung auf Querdruck wird durch den Ausnutzungsgrad ηc,90 in [%] angegeben.

Results compression perpendicular to grain

In der folgenden Skizze wird der Verlauf der effektiven Fläche Aef,max über die Querschnittshöhe (rote Linie) sowie der Verlauf der angenommenen Lastausbreitung (blaue Linie) angezeigt.

Distribution of the effective Area

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