Module „CLT-Plate 1D - Continuous beam“

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 fire and vibration parameters

A graphical representation of the input data is shown on the right side. This offers the possibility for a fast check of the input data.

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.

In the current version a continuous beam with a maximum of 7 spans including a cantilever on the left and right side can be analysed. The supporting width and span of field (via x-value in the table) can be defined within this input field.

The cross section can be defined by the user or by choosing a typical cross section of a proprietary CLT product. Des Weiteren besteht auch die Möglichkeit eigene BSP-Aufbauten abzuspeichern. 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.

Über den Button kann der aktuelle Querschnitt in der Bibliothek gespeichert werden und später über die Auswahl "Meine BSP-Aufbauten" wieder aufgerufen werden.

Mit dem Button kann die Bibliothek angezeigt werden.

• Mit kommt man in den Bearbeitungsmodus. Derzeit kann nur der Name des abgespeicherten Aufbaus geändert werden.
• Mit werden die Änderungen gespeichert.
• Mit kann der in der Seitenleiste ausgewählte Aufbau aus der Bibliothek entfernt werden.
• Mit können Aufbauten aus einer csv-Datei importiert werden.
• Mit können die Aufbauten der Bibliothek in eine csv-Datei exportiert werden.

The loads are divided into the dead load (weight of the plate) (g_0,k), permanent loads (g_1,k), imposed load (q_k), snow load (s_k) and wind load (w_k). This classification is necessary to automatically carry out calculations for different load case combinations.

The plate weight is calculated automatically. The calculation method can be selected in the settings/preferences window. The default calculation method is in accordance with ON B 1991-1-1. A unit weight of 5.5 kN/m³ is assumed in the calculation. However, the unit weight may also be calculated using:

• calculation based on the arithmetic average of density of the chosen material
• calculation based on a user-defined density

When entering the imposed loads, one of the following categories has to be chosen:

• A: Areas for domestic and residential activities
• B: Office areas
• C: Areas where people may congregate (with the exception of areas defined under category A, B and D)
• D: Shopping areas
• E: Areas for storage and industrial activities
• F: Traffic and parking areas for light-duty vehicles
• G: Traffic and parking areas for medium-duty vehicles
• H: Roofs

When entering the snow load, the country code or an altitude above sea level where the structure will be located has to be specified:

• < 1000 m
• > 1000 m
• FIN, IS, N, S

The span of each field can also be modified in this table.

Einzellasten

By choosing "Fire above" and/or "Fire below" in the tab "Fire" a structural fire design has to be carried out. The "Fire duration" is specified in minutes and can be increased (or decreased) by increments of 30 minutes by pressing the up (or down) arrows, or defined by entering a specific duration between 0 minutes and 240 minutes in the allotted box. By ticking the box next to "Fire protection" a layer of fire protection is added to the plate, but the effective protection time of the protection layer needs to be defined.

For a user-defined cross section, options are given for specifying heat resistant adhesives, presence of grooves, and whether the layers are edge-glued. For proprietary CLT products both values are set automatically and they cannot be changed.

The values k_fire (conversion factor 20%-quantiles) and d₀ (layer thickness to take into consideration the influence of temperature exposure) are pre-set and cannot be changed. The charring rate is dependent on the option edge glued or without groove. For a user-defined cross section this value can be changed.

The tab "Vibrations" allows for vibration verification.

For the vibration verification the following specifications are of importance:

• high oder 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)
• plate 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.

Load combinations are compiled based on the input loads entered in the "Loads" field. The respective k_mod- and k_def-values can be determined automatically based on the classification of loads (plate weight, wind load, etc.).

Output values generated in the tab "Cross section values" field include the effective stiffness (depending on the chosen calculation method), the position of the centre of mass for the full cross section and also for the charred cross section in case of structural fire design.

A summary of the verifications can be retrieved via the tab "Verifications". The utilisation ratios for various limit states are colour-coded indicating if the verification is fulfilled (green), not fulfilled (red) or a more accurate verification is needed (yellow). The locations of the maximum utilisation ratio and the governing combinations are compiled in the same way.

The tab "Utilisation" shows the distribution of the governing utilisation ratios along the beam. Areas in which the results may differ from the exact solution are marked here.

The tab "Stresses" shows the governing stresses resulting from the ULS verification. If a structural fire design was carried out, the governing stresses in case of fire are shown in the tab "Stresses in case of fire"

The tab "Deformations" shows the deformed system or the envelope given by the minimum and maximum deformation resulting from the governing SLS verification.

In der Karteikarte „Details“ können detaillierte Ergebnisse abgerufen werden. Im Baum auf der linken Seite kann der jeweilige Lastfall oder die jeweilige Kombination ausgewählt werden.

Die Ergebnisse (Schnittgrößen, Verformungen) dieser Auswahl werden dann in der Tabelle rechts oben für die Berechnungspunkte (Anzahl je nach Angabe in den Einstellungen) angegeben.

Nach Auswahl einer gewünschten Stelle können rechts unten - je nach Auswahl der Karteikarte - die Lasten und Auflagerkräfte, der Schnittkraft- und Verformungsverlauf sowie die berechneten Spannungen betrachtet werden.