Cross-sectional characteristics
Cross-section is the fundamental parameter of the member. Cross-sectional parameters may be specified with the help of pre-defined databases, using external programs or entered manually.
Cross-sectional characteristics
Following characteristics are considered in the analysis:
b |
|
h |
|
ycg |
|
zcg |
|
A |
|
P |
|
Ay |
|
Az |
|
Iy |
|
Iz |
|
Dyz |
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Ik |
|
Iω |
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Input of cross-section
The cross-section may be defined using these options:
- The cross-section can be selected from pre-defined database, the characteristics will be calculated automatically by the software according to the specified dimensions.
- The cross-section can be created with the help of programs "Section" and "Sector". The characteristics are calculated by these programs and are transferred into the software. This option provides only limited number of characteristics. Therefore, shear areas and rigidity moments in torsion are equal to zero.
- The cross-sectional characteristics can be specified manually by the user.
The cross-sectional characteristics are checked after the manual input. The cross-sectional area and moments of inertia can't be zero. Also the rigidity moment in simple torsion Ik has to be bigger than 0. As this value isn't significant in the most of cases, the estimation of the value is available. The estimation is based on the St. Venant expression, that works fine for massive cross-sections, however does not provide sufficient results for thin walled cross-sections.
The part of cross-sectional characteristics is also the rotation of the cross-section relatively to the local coordinate system of the member. The rotation is the angle between axes y,z in cross-sectional coordinate system and axes 2,3 of local coordinate system of the member. This angle is positive if the cross-section is rotated in anti-clockwise direction for the view against the axis 1 of local coordinate system of member.