Midside Node Results for ANSYS Output Files

HyperView supports midside node results, and calculates midside node results for stress and strain tensors even though result output files do not have midside nodes.

ANSYS output files [RST, RTH, RMG] do not have results at midside nodes for tensors.

Results at midside nodes provide much more accurate prediction of results. Contour plots with midside node results predict correct simulation of a system. Refer to the examples below:

Figure 1. Fig 1: Model with loads and boundary conditions

Figure 2. Fig 2: Stress plot with results at midside (HyperView 9.0 and later)

Figure 3. Fig 3: Stress plot without results at midside nodes (HyperView 8.0 and previous versions)

You can see that the load pattern shown in figure 1 – Stress plot with results at mid side node - shows the correct pattern of results.

Calculation of Results at Midside Nodes

Figure 4.
  • Results at midside nodes are the average of corner results.
Example at m11 =[c11+c14]/2; m21 =[ c21+c24]/2
  • Values at midside nodes are averaged at tensor components level. Secondary results are then calculated from these component tensors at the midnodes. Secondary stresses/strains at midside nodes are not average of secondary stress/strains at corner nodes.
  • With “average options”, values at midside nodes are averaged before averaging corner results.
  • In case of “average options”, if midside nodes are shared by 2 or more elements, then the average value will be reported at a shared node. In the image shown above, at shared node it is = [m12+m22]/2

Important Points

  • All post processors available commercially do not support midside nodes.
  • With midside node result support in HyperView, contour plots from other post processors that do not show results at midside node may not match.
  • Legends for contours, maximum and minimum values may not match as results at mid side nodes are considered for legends and maximum and minimum values.

    What should match?

  • If you are comparing with post processor that does not support mid side node results, individual corner result should match, for average and non average options.