Finite Element Analysis (FEA) utilises a number of different element types to mathematically represent different structural elements. Neara uses a subset of FEA elements which are frame, truss, cable and rigid.
Given a pole with a cross arm, single brace, two cables, and a stay.
The FEA model will split this into the various FEA elements with each assigned a color:
Green for braces
Red for rigid elements
Brown for frames
Blue for cables
Orange for external point loads
Black for nodes, though these appear as labels only
Red cross for fixed node
For instructions on how to view the FEA model as per below, see Viewing FEA model.
Frame
Frame elements can transfer bending moments and forces.
Poles and crossarms are modelled as frame elements.
Truss
Truss elements can only transfer forces in tension or compression but do not transfer bending moments. They can be thought of as a ball joint at each end and hence can freely rotate in all directions.
Braces are modelled as truss elements and will handle forces in both compression and tension.
Cable
Cable elements transfer axial tension, along the cable so the direction and magnitude of the force vector at the connection point, such as crossarm will depend on how the cable is sagging. The more the cable sags the higher the vertical component to the force.
Wires, stays, aerial stays, cable and suspension insulators are modelled as cable elements.
Rigid Element
Rigid elements are intended to transfer moments and forces without deforming.
Connection between the cross arm and the pole, pin insulators, and rigid post insulators are modelled as rigid elements. Note post insulators can also be modelled as a beam that have flexibility.
Choice of element
The type of element does not depend solely on modelled object type, instead this can be altered by manipulating FEA solve configurations.
For example,
Strain or suspension insulators can be modelled as very short rigid elements, instead of cables elements, such that they don't affect the stability of the simulated FEA model
Note Neara does not have composite elements, for example a frame on one side and a truss on the other.