You can select one or more nodes and then create a coordinate system directly in the Geometry window. The new coordinate system is created at the location of the selected node or the centroid of multiple nodes using the (X, Y, Z) locations, rather than the nodes themselves, to ensure that the location does not change upon re-meshing.
To create a coordinate system from nodes in the Geometry window:
Using the Node selection filter on the Graphics Toolbar, select a node.
Right-click the selected nodes and select Create Coordinate System.
A new coordinate system is created at the location of the selected node or the centroid of multiple nodes.
If you re-mesh the body at this point, you will see that the coordinate system remains in the same location, as it is based on node location rather than node number.
Creating an Aligned Coordinate System
You can also select an individual node and create an aligned coordinate system on a solved vector principal stress or strain result.
Note: While you cannot create an aligned coordinate system based on multiple nodes, you can create a local coordinate system at the centroid with an axis oriented in the direction of the global coordinate system.
To create an aligned coordinate system:
From the Tree Outline, select a Vector Principal Stress or Vector Principal Strain result.
Using the Node selection filter on the Graphics Toolbar, select one or more nodes.
Right-click in the Geometry window and select Create Aligned Coordinate System.
A coordinate system is created. The Y-axis of the local coordinate system is oriented in the direction of
S1(direction of max.principal stress).
Note: Vector Principal Stress and Vector Principal Strain results cannot be applied to line bodies or a node located on a line body. As a result, any automatically generated (aligned) coordinate system would be incorrect.