Cross sections toolbar

Create a steel cross section from library

 

 

CivilFEM hot rolled shapes are most commonly utilized in commercial building fabrication and construction and heavy industrial manufacturing. The steel shapes library includes a broad range of sizes & grades such to match any worldwide project's exact specifications.

 

"Steel from library" option allows the user to choose among different shapes from the catalog.

 

Type of shapes available:

 

Two options exist when considering the checking/design mechanical properties. The first option, “Mechanical properties from library/ by user” (1) automatically selects the code properties for that particular section. The user can modify the parameters to adapt the section to suits the user’s needs.

 

With the other option, “Mechanical properties autocalculated by plates” (2), CivilFEM calculates the mechanical properties as if the section was designed using plates. The plate section                approximation can be seen clicking Show.

 

Solving a model taking into account the mechanical properties of a section instead of the tessellation, is equivalent to solving the model with a generic section.

 

Create a steel cross section defining each plate

 

In order to design a steel cross section in this way, a material needs to be created to assign it in the property bar.

 

The plate structure describes the section as a group of independent plates (webs or flanges) in order to check elements with Eurocode No.3. Section is defined by the user by plates. For each plate, the following data is defined:

 

 

Point coordinates according to YZ section coordinate system.

 

Once previous step is done, the following property bar is shown.

 

 

Solving a model taking into account the mechanical properties of a section instead of the tessellation, is equivalent to solving the model with a generic section.

 

An example will be illustrated below in order to see how to use "Add" option.

 

 

Add button must be clicked if a new plate is required.

 

If the user wants to delete any plate, the Remove option is available for this action.

 

 

Plates must be defined by connecting the end point 2 of previous plate to the end point 1 of next plate. The starting plate can be selected anytime.

 

"Steel by plates" tool is really useful if the user needs to design a complex profile.

 

Create a steel cross section by dimensions

 

 

Once the properties required for the steel section are applied, the section is entirely defined. The property bar gives the following information:

 

Solving a model taking into account the mechanical properties of a section instead of the tessellation, is equivalent to solving the model with a generic section.

 

The dimensions for different steel shapes are shown below:

 

 

 

a: height.

b: width.

c: web thickness.

d: thickness of horizontal flange.

e: thickness of vertical web.

f: flange thickness.

g: outer diameter.

h: wall thickness.

 

 

 

Create a concrete cross section

 

The dimensions for different concrete shapes are shown below:

 

 

a: height.

b: width.

c: outer diameter.

d: web thickness.

e: top flange length.

f: top flange thickness.

g: bottom flange length.

h: bottom flange thickness.

i: thickness of vertical web.

j: thickness of vertical web.

k: wall thickness.

 

This is the whole group of concrete sections available to perform a beam structural element. For further information about the captured concrete section and the concrete section defined by points, click on Generic concrete sections.

 

Once the properties required for the concrete section are applied, the section is entirely defined. The property bar gives the following information:

 

 

Solving a model taking into account the mechanical properties of a section instead of the tessellation, is equivalent to solving the model with a generic section.

 

In regards to the mechanical properties type, four types are available: gross, net, homogenized and defined by user.

 

 

REINFORCEMENTS

 

CivilFEM allows the definition of reinforcement for a concrete beam section, once required section has been defined.

 

This information will be complemented in the corresponding Reinforcements annex.

 

Both a concrete material and a reinforcement material are  necessary to define a reinforced concrete section. This reinforcement material will be used to reinforce the whole section, both longitudinally and transversally.

 

In the picture below all available reinforcement types are shown.

 

 

Reinforcement for beams can be defined for: bending + axial, shear and torsion loads. The mechanical cover (mc) is defined by the user, and will affect the rebar location.

 

Bending + Axial reinforcement

 

 

The reinforcement class defines if reinforcement is fixed or scalable. The user may design a beam with an insufficient reinforcement amount. CivilFEM will provide the needed reinforcement for those reinforcements in which the "Scalable" option is activated after performing a design by code. On the other hand, if "Fixed" option is activated, will not be modified. This tool will be very useful for "Design beam" tool.

 

Point 1 and Point 2 make reference to both ends of the same reinforcement line.

 

Geometry properties bar option defines if reinforcement must be set as a straight segment or as a circumference.

 

The bottom part of this chart will be detailed below:

 

The reinforcement definition may be done by amount, number of bars or by separation.

 

 

By amount                                                                 By number of bars                                                       By separation

 

                                                     

 

Distribution defines the reinforcement location inside the section (formulation and pictures in "Reinforcement" chapter.

 

 

CivilFEM provides the proper number of reinforcement amount depending on the section type the user wants to create. However, if another reinforcement group needs to be added, it can be easily done within the "Add" option inside the contextual menu.

 

 

The user can make use of the "Show" option to visualize the reinforcement status.

 

Shear reinforcement

 

Only one group of shear reinforcements may be defined for each cross section.

 

                                 

 

 

Angle with respect the longitudinal axis (90º by default):

 

 

Torsion reinforcement

 

Only one group of torsion reinforcements may be defined for each section. Torsion reinforcement has two components:

 

 

                                           

 

Create a cross section for a cable

 

 

A cable section is available not only for steel material but also for reinforced and prestressed steel.

 

"Outer diameter" is refers to the cable thickness.

 

Create a generic cross section

 

"Generic section" tool is useful in case of needing a section not included among the ones that CivilFEM offers.

 

Parameters:

 

 

The torsional stiffness K is calculated as:

 

If J is not 0.

 

 

In the case J=0, the torsional stiffness K is calculated using

 

 

 

 

Merge two sections (steel and concrete) into one section. Mesh elements are duplicated when the beam is meshed in order to take into account the activation time of each part. Also an offset is set to each concrete and steel element to apply forces into the center of gravity of composite section

Define the activated cross section.