Define Superposition Method

 1. Remove enough redundant supports to reduce the structure to a statically determinate condition

2. Calculate the deflections at the previous locations.  Use consistent sign conventions

3. Apply each redundant support as a load and find the deflections at the redundant support as a function of these forces

4. Use superposition to combine the deflections due to the actual and redundant loads.  The total deflection must be known (at a support is typically zero).