Module "Ribbed slab"

Input data

The input is divided into:

general information about the project and the considered structural element
definitions of the structural system
definitions of the cross section
input of the loads
informations about vibration parameters
calculation options

General

The input field "General" defines the service class. It is only allowed to use CLT elements in areas of service class 1 and 2.

Service class 1 (interior service condition) is in general consistent with a common utilisation of living spaces.
Service class 2 (protected exterior service condition) is generally used for open but roofed structures.

General · 2017/11/14 17:11

Structural system

In this release, only single span girder can be calculated. The supporting width and span (via x-value in the table) can be defined within this input field.

Cross section

The input of the CLT cross section (plate cross section) is the same as for the other Module. However, you can still select whether the plate is at the top or bottom.

Show description

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.

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 .

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 t_n;orientation of the layers o₁ to o_n (0 or 90);name of material

Example:
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.

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: ";"

Example:
Name;f_m,k;f_t,0,k;f_t,90,k;f_c,k;f_c,90,k;f_v,k;f_r,k;E_0;E_0,05;E_90;G;G_r;rho_k;rho_mean;f_v,k,IP;f_T,k;f_m,k,IP
;N/mm2;N/mm2;N/mm2;N/mm2;N/mm2;N/mm2;N/mm2;N/mm2;N/mm2;N/mm2;N/mm2;N/mm2;kg/m3;kg/m3;N/mm2;N/mm2;N/mm2
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.

Optimization of layup

Use the button to display the window for 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.

Cross section · 2017/11/14 17:11

The rib cross-section (rectangular cross-section made of glulam or solid wood) is defined by entering the height and width of the rib and selecting the material. If "Standard dimensions only" is selected, the dimensions for the nearest standard cross-section are set.

Loads

The input is the same as for the Module "CLT-Plate 1D - Continuous beam", but limited to distributed loads.

Show description

Fire

In this module, currently no structural fire design is possible.

Vibrations

The tab "Vibrations" allows for vibration verification.

For the vibration verification the following specifications are of importance:

high or normal requirements? This choice will have an influence on the limit values.
modal damping factor
consideration of the screed (concrete topping) stiffness
- thickness of the screed (concrete topping)
- modulus of elasticity of the screed (concrete topping)
support (2-sided or 4-sided)
room width b perpendicular to the load carrying direction

The effective width b_w of the chosen cross section used by the stiffness criteria will be specified.

Vibrations · 2017/11/14 17:11

Results and Output

Cross section values

On the tab "cross-section values", the effective width, the center of gravity as well as the bending and shear stiffness of the T-beam at the supports and in between are shown.

The button can be used to display the stiffness values of the CLT panel, the glulam beam and the shear spring, which are the input parameters for determining the effective width.

Summary of the results

The summary of the results is analogous to the Module "CLT-Plate 1D - Continuous beam".

Show description

However, there are differences for ULS - shear, since for the CLT-flange also the in-plane shear has to be considered.