Stress recovery

a code is written to extract stress in 2D plane stress analysis

In engineering analysis one is interested in stress values for the structure. This code shows how stress values are obtained from displacement's. Stress values are accurate at the Gauss points and these stresses are used to obtain the stresses at nodal points. Methods like Extrapolation or Patch Recovery can be used. Stresses obtained are averaged to get average stresses. Code shows how to extract stresses and find element nodal stresses, how to average them and how to find vonmises stresses.