Errors in loads and boundary conditions represent one of the more subtle errors that can take place in an analysis model, as well as one of the more potentially serious ones. For example, a set of load symbols on a model may look the same with ten times the intended value, but will cause a dramatic difference in the analysis result. Similarly, a boundary condition applied to a sparse number of finite elements may appear to be the same as one applied to an entire edge of a geometric model. This makes it critical to verify your loads and boundary conditions prior to analysis.

There are two primary ways to verify the load and boundary conditions that you have applied to
your model:

As discussed earlier, the Loads/BCs menu provides two primary ways of displaying LBC data graphically on your model: Plot Markers and Plot Contours. The first of these techniques, Plot Markers, comes automatically with most cases of modeling loads and boundary conditions.

Whenever you create or modify LBCs data, visual markers display on your model by default. These symbols are coded by color and shape to correspond to your specific Loads/BCs, with some examples shown here.

These displays become a permanent part of your display until they are explicitly cleared. The Display -->Loads/BCs/El.Props menu can be used to manage turn on, turn off, change the colors or manage the display of these symbols.

In addition, you can enable the Show on FEM Only toggle to display LBCs data on the finite elements themselves, even if they had been originally applied to geometric entities. This can represent an important additional form of display verification, because symbols displayed on geometry are only shown along the visualization lines defined in the Display /Geometry menu.

The Show on FEM Only toggle causes these symbols to be displayed at each node or element of the finite element model, which more accurately displays how the analysis program will see these loads and boundary conditions.

For scalar values, an alternative form of display is to use the Plot Contours action to display a color fringe display of the load data on the surface of the model. These scalar values can either be direct scalar quantities, such as temperature, or a scalar component of a vector quantity, such as the X-component of an applied force.

To plot contours:

The spectrum values and color coding for these contour displays will span the range of values by default, but can be modified using the Display --> Spectrums menu. When you no longer wish to display this contour plot, select the Reset Graphics button on the Plot Contours menu form.

To verify your load and BC values numerically, you can use the Show Tabular action of the Loads/BCs application form to create a spreadsheet-like display of data for the current load case.

These display and verification capabilities all pertain to the current load case. To look at results from other load cases, make these load cases current using the Loads/BCs or Load Cases applications forms.

An even more important form of verification has nothing to do with software at all; that is to critically evaluate your analysis results with an eye towards what you would expect in the physical world.

When an analysis result seems dramatically more or less than you would expect in an actual model, the first place where you should look for a discrepancy is in the values of your loads and boundary conditions. Together with checking other values such as material and element properties, proper verification of load and boundary condition values helps create an extra margin of confidence in the accuracy of your analysis simulation.