To fix warped surfaces

To realign warped surfaces with a plane defined by a set of selected nodes or the surface axis, use the following procedure.

If the surface is selected without any nodes, then the coordinates of each surface vertex are converted to the local axis system. Any vertex with a non-zero local z coordinate is replaced with a new vertex node with the same local x and y coordinates and a 0 z coordinate.

Similarly, if three nodes are selected, the vertex nodes of the surface are moved to the plane defined by the selected nodes.

Note: If three nodes are selected, then they should not be colinear in order to define a valid plane.

Select either:

three nodes and a one or more surfaces – the selected surfaces are aligned to the plane defined by the nodes

or
only surfaces – the selected surfaces are aligned to the plane defined by the local 1 & 2 axes
On the Surfaces ribbon tab, select the Fix Warped Surfaces tool in the Edit group.

Note: If you selected all the nodes of the surface, an error is displayed in the messages drawer.
If this is the first time you have used this tool during this work session, then a warning message is displayed prompting you to review the changes any objects connected to nodes moved as a result of this action.
Click OK.