Results Interpretation: Expanded Envelope Results
Description
The basic function of the envelopes is to find the maximum or minimum values of a particular quantity across a range of result cases.
For example, the Peek window below shows the maximum node displacements occurring at node 591 for the selected cases. The grid shows that the maximum D(X) of 1.662 occurs at result case 4 (C.4). Similarly, the maximum D(Y) of 4.665 occurs at result case 5 (C.5). In other words, each of these quantities has been independently enveloped.
Where the enveloped quantities are vector or tensor quantities (e.g., node displacement, node rotation, node reaction, beam forces/moments, plate stress, etc.) we may also need to also know the equilibrated set of components that occur when one of those components is a maximum or minimum. For the case of displacement illustrated above, we may wish to know what the corresponding other displacements and rotations are when DX is at a minimum. Similarly, we may need to know that the axial force in a beam is when the a bending moments is at a maximum.
As the enveloping function provides the information about the case that produces the envelope value, one way to obtain the equilibrated set is to go to each result case in turn and extract the required results. A more efficient way is to show the Expanded envelope results as shown below. The highlighted cells (the diagonal cells of the grid) contain the envelope values from the envelope summary above.
Each row of the expanded envelope results is an equilibrated set of results from respective result cases. For example, the maximum DY of 4.665 mm comes from result case 5 which also produces DX of 0.0468 mm, DZ or -1.312 mm , RX of 0.0184 degree, RY of -0.0195 degree and RZ of 0.0064 degree.
The expanded envelope results are also known as concurrent results in some literature.
The expanded envelope results are also available in The LISTINGS Tab; a dropdown list containing the options ENVELOPE: Summary and ENVELOPE: Expanded becomes visible when expanded envelope results are available.
See Also