2.1 Node

Node object represents the member or surface end joints or supports in finite element analysis.

Figure 2.1.1: Node object as member end joints.

In OpenBrIM, a Node object supports six degrees of freedom (DOFs): translation X, Y and Z; and rotation X, Y and Z.

Based on the way structural components are positioned in 3D space, it is possible to have nodes at the same location (ex. top of one component is at the same location as the bottom of another component sitting on top). In the case of OpenBrIM app, the nodes will automatically be merged before going into analysis phase.

Syntax

<O T="Node">

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</O>

Elements

Parent elements: Group, Repeat, FEA Line, FEA Surface

Child elements: Parameters

Parameters

All the DOFs are by default free, which means nodes are by default free to translate and rotate as long as the connected finite elements allow them to do so. Each DOF can be supported independently using Tx, Ty, Tz, Rx, Ry and Rz parameters. Value of zero for these parameters means node is free in that direction (default). Value of -1 means the DOF is fully fixed (supported/restrained). Any other value is taken as the stiffness at that node (partial fixity, K).

Note that X, Y and Z parameters can be shortened to:

<O N="N1" T="Node" X="0" Y="0" Z="0">

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.

</O>

Example

<O N="Finite Element Model " T="Project">

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.

<O N="Frame" T="Repeat">

<P N="S" V="0" />

<P N="E" V="n_col-1" />

<P N="I" V="1" />

<P N="CTRL" V="index" T="Text" />

<P N="index" V="0" />

<O N="Geometry" T="Group">

<P N="EndUserInputFields" V="1" />

<P N="n_col" V="4" D="number of columns" />

<P N="h_col" V="50" D="column height" />

<P N="b_col" V="1" D="column width" />

<P N="d_col" V="1" D="column depth" />

<P N="b_bm" V="1" D="beam width" />

<P N="d_bm" V="1" D="beam depth" />

<P N="s_col" V="15" D="column spacing" />

</O>

.

.

.

<O N="NB" T="Node" X="index * s_col">

<P N="Tx" V="-1" />

<P N="Ty" V="-1" />

<P N="Tz" V="-1" />

<P N="Rx" V="-1" />

<P N="Ry" V="-1" />

<P N="Rz" V="-1" />

</O>

<O N="NT" T="Node" X="index * s_col" Z="h_col" />

</O>

</O>

Figure 2.1.2: Node object.