The simple solution is to not plot the stress close to the fixed constraint. St. Venant's principle is that the stress far from a disturbance will be the same as the stress if there was no disturbance. There are two ways to only plot stress far from the distubance of the Fixed Support.

1. In Geometry

Use SpaceClaim to create a plane at the fixed end, then use the Move tool to offset it from the fixed end about 1-2 diameters of the line. Use Split Body to cut all the strands. On the Workbench tab, use the Share button to create Shared Topology so when the geometry is meshed, the elements share nodes at the cut boundary and no bonded contact is needed. Plot the stress on the bodies to the left and don't include bodies near the Fixed Support.

2. In Mechanical using Named Selections of Nodes

Create a Named Selection in the Worksheet of Nodes that have a Z coordinate > whatever value is needed, which will exclude all the nodes that have the artificially high stress. Plot the Stress using that Nodal Named Selection.