Cross section records

These records specify a cross section model descriptions. The general format is following:

*CrossSectType

(num#)(in)

The order of particular cross section records is optional, cross section model number is determined by (num#)() parameter. The numbering should start from one and should end at n, where n is the number of records.

The crossSectType keyword can be one from following possibilities

• SimpleCS

  [thick(rn) #] [width(rn) #]

  
  Represents integral type of cross section model. In current implementation, such cross section is described using cross section thick (thickVal) and width (widthVal). For some problems (for example 3d), the corresponding volume and cross section dimensions are determined using element geometry, and then you can omit thickVal and widthVal parameters.

• LayeredCS	nLayers(in) #
  	LayerMaterials(ia) #
  	Thicks(ra) # Widths(ra) #
  	midSurf(rn) #

  
  Represents the layered cross section model, based on geometrical hypothesis, that cross sections remain planar after deformation. Number of layers is determined by nLayers parameter. Materials for each layer are specified by LayerMaterials array. For each layer is necessary to input geometrical characteristic, thick - using Thicks array, and width - using Widths array. Position of mid surface is determined by its distance from bottom of cross section using midSurf parameter (normal and momentum forces are then computed with regard to it's position). Elements using this cross section model must implement layered cross section extension. For information see element library manual.

• FiberedCS	nfibers(in) # fibermaterials(ia) #
  	thicks(ra) # widths(ra) # thick(rn) # width(rn) #
  	fiberycentrecoords(ra) # fiberzcentrecoords(ra) #

  
  Cross section represented as a set of rectangular fibers. It is based on geometrical hypothesis, that cross sections remain planar after deformation (3d generalization of layered approach for beams). Paramater nfibers determines the number of fibers that together form the overall cross section. The model requires to specify a material model corresponding to particular fiber using fibermaterials array. This array should contain for each fibre corresponding material model number (the material model specified on element level has no meaning in this particular case). The geometry of cross section is determined from fiber dimensions and fiber positions, all input in local coordinate system of the beam (yz plane). The thick and width of each fiber are determined using thicks and widths arrays. The overall thick and width are specified using parameters thick and width. Positions of particular fibers are specified by providing coordinates of center of each fiber using fiberycentrecoords array for y-coordinates and fiberzcentrecoords array for z-coordinates.