The results of a modal analysis are accessed via the Modal property of the Results object. This property returns a reference to a ModalResults object that contains the results for all the mode shapes computed by the analysis. The properties of the ModalResults object are outlined in the table below.
|
Property |
Type |
Description |
|
Application |
Application |
Read Only. Returns a reference to the parent application. |
|
Cases |
ResultCases |
Read Only. Returns a reference to the object that contains results at the nodes, elements and members in the frame. |
|
Frame |
Frame |
Read Only. Returns a reference to the parent frame object. |
|
Frequencies |
Variant |
Read Only. Returns an array containing the natural frequencies computed by the modal analysis. |
|
Frequency |
Double |
Read Only. Returns the natural frequency of the specified mode shape. |
|
ModalMass |
Double |
Read Only. Returns the modal mass of the specified mode shape. |
|
NoOfModes |
Long |
Read Only. Returns the number of modes computed by the modal analysis. |
|
ParticipationFactor |
Double |
Read Only. Returns the participation factor of the specified mode shape for the specified degree of freedom. |
|
ParticipationRatio |
Double |
Read Only. Returns the participating mass ratio of the specified mode shape for the specified degree of freedom. |
The modal displacements are stored in a ResultCases collection object; each item in the collection corresponds to a single mode shape computed by the analysis. These results are referenced as follows.
Dim myResults As Multiframe.ResultCase
'Get modal results for mode shape 2
Set myResults = myFrame.Results.Case(2, mfAnalysisModal)
'And using the object hierarchy to get the same results
Set myResults = myFrame.Results.Modal.Cases(2)
The ModalResults object also encapsulates some extra information derived from the analysis such as the number of mode shapes computed by the analysis and the frequency of each mode shape. The number of modes actually computed by the modal analysis of the frame is obtained from the NoOfModes property. For each of the computed mode shapes, the natural frequency is available from the Frequency or Frequencies properties of the ModalResults object. The Frequency property returns the natural frequency of particular mode and requires a single parameter identifying the mode. However, the frequencies of all mode shapes can be obtained directly by calling the Frequencies property. This property returns a variant containing an array of frequencies for each of the mode shapes.
Dim myResults As Multiframe.ResultCase
Dim freq as Double
Dim myVar as Variant
'Get modal results for mode shape 2
Set myResults = myFrame.Results.Case(2, mfAnalysisModal)
'And the frequency for this mode
freq = myResults.Modal.Frequency(2)
’And the same frequency from an array of all frequencies
myVar = myResults.Modal.Frequencies
freq = myVar(2)