A section is the cross-section geometry of the member. Different sections have different bending, cesoia, e proprietà torsionali. Sections require a material assignment so that the geometry of the section can have material properties required for analytical and design calculations.
Sections can be created in two ways.
- In the form by directly specifying the values:
- Nome (Opzionale)
- ID materiale – The material of the section specified by ID.
- La zona (without a direct shape assigned through the Section Builder, it will assume a rectangular cross-section)
- Iy – Moment of Inertia about the Y-axis
- A partire dal – Moment of Inertia about the Z-axis
- J – Costante di torsione
- Shear Area Y (Opzionale)
- Shear Area Z (Opzionale)
- Using the Section Builder
The datasheet can only be used to view sections. It cannot be used to add or edit sections.
Nota: Shear Deformations (Euler-Bernoulli vs Timoshenko Beams)
If the shear areas are specified then shear deformation is taken into account (vale a dire. the member using the section is considered a Timoshenko Beam). In most applications, the shear deformation is negligible compared to flexural deformations.
When the shear areas are not specified in the section’s form then the shear area is taken as infinite, meaning that no shear deformations are accounted for (vale a dire. the member using the section is considered an Euler-Bernoulli Beam). It is recommended to keep the shear areas empty as shear deformation is usually negligible.
Generatore di sezioni
SkyCiv’s Section Builder is integrated into Structural 3D and allows users to quickly and easily model various types of sections.
General shape templates are included for the following shapes:
- Rettangolare vuoto
- Circolare cava
- Angolo (L-Beam)
- Doppio angolo
- Doppio canale
- Triangolare cavo
- Trave a scatola
For shapes not available in the templates, custom shapes can be defined in 3 diversi modi:
- Points Shapes – Define points to create a polygon. Specificare i raccordi in qualsiasi punto.
- Line Shapes – Definisci un percorso di linea e crea un poligono con uno spessore e un raggio.
- Importazione di DXF – 2D shapes drawn in external CAD programs can be saved in DXF format and imported into SkyCiv’s Section Builder.
Built-up sections can be modeled by adding multiple shapes and performing operations (translating, rotating, mirroring) on them.
Composite sections can be modeled by assigning different materials to different shapes.
Nota: SkyCiv does not currently support composite I-shaped beam design
Holes and cutouts can be specified by checking the “Cutout” Tutti i membri dovrebbero ora essere evidenziati in blu.
Clicking ‘Calculate’ will display a summary of the geometric, curvatura, cesoia, e proprietà torsionali. però, it will NOT submit the section to the section ID.
Clicking ‘Submit’ will assign the section to the section ID. Members assigned with this section ID will have this cross-section.
Nota: Cross-section assignment to member
It is important to note that when a member gets assigned to a cross-section, il line of the member always acts through the centroid of the section. This is to clarify that the (0,0) coordinata (origine) of the section builder is not by default the centroid. You can sketch and translate your section anywhere on the z-y cartesian plane, and the member will be assigned to the true centroid.
Translations and rotations of shapes allow for relative positioning of shapes when creating a section that is made up of more than 1 shape. If you don’t want the line of the member to pass through the centroid, then you can use the “Offset A” and Offset B” of the member.
Esempio: How to name your sections
Per impostazione predefinita, when you add your sections, they will be named by their (rounded) height x width dimensions. To the left of the name will be an icon representing the section (per esempio. in the example below the “io” icon represents an I-beam). If you are using a database section, the name will automatically default to the database section name and nomenclature but can be modified.
This may not be meaningful to you so you can optionally change the name. Per fare questo, è sufficiente fare clic sulla sezione per visualizzare le opzioni del menu a sinistra. Nel “Nome (Opzionale)” campo, enter in a name you prefer.
Per esempio, Ho apportato questa modifica e il risultato è ora il seguente.