# Nodes
Nodes are used to locate points in space. Elements are located in space by referring to nodes in their topology lists. Loads may be applied to nodes. The Node Definition dialog may be used to define node all attributes of nodes.
# Basic Definition
Node Coordinates
Coordinates are defined with respect to the current grid plane, which defaults to the global grid (i.e. global axis directions). Coordinates are stored in global axes, regardless of the current grid plane. For structures specified as “Plane”, only X and Z are required; for “Grid” only X and Y.
The ‘Sculpt | Node Operations | Convert Nodes to Standard’ and ‘... | Convert Nodes to Grid’ commands may be used to convert the node status, maintaining their position in global space.
Constraint Axis
Constraint axes are used for specifying restraints, joints, constraint equations and applied displacements and results at nodes, in non-global directions.
The constraint axes default is global, but user-defined axes can be specified by typing the axis record number as specified in the Axes Table.
Restraint Direction
Any combination of translational and rotational restraint can be specified for each node. Restraints will be in global or user-specified axis directions, depending on the constraint axis.
Nodal Stiffness
Nodes can be assigned a stiffness. The stiffness is specified as a property. These properties act in the constraint axis system of the node.
Nodal Damping
Nodes can be assigned a damping. The damping is specified as a property. These properties act in the constraint axis system of the node.
Nodal Mass
Nodes can be assigned a mass and inertia. This is specified as a property. These properties act in the constraint axis system of the node.
The node definition dialog is used to define or modify a node. This dialog can be activated from Nodes table view using the wizard button or from a Graphic View by selecting a node and then “Edit Node” from the right-click menu.
The units are displayed in the top right corner of the dialog.
Name
The name is used only as a label for the node. (default: blank)
Coordinates
The location of the node in the global axis system in the current units. Plane structures have only x and z coordinates; grid structures have only x and y coordinates. In these cases the coordinate that is not relevant is greyed.
# Constraints
The constraints define if the node is fixed in particular directions. This is done by selecting an axis, normally global and selecting the directions to restrain. Directions that do not apply for that structure type are disabled. The restraint types Free, Pin and Encastre options provide a shortcut to setting the flags for the individual degrees of freedom. The symmetry options in the xy plane, yz plane and zx plane provide shortcuts for applying the boundary conditions corresponding to symmetry in these planes. The symmetry options do not unset other restraint conditions.