Convert the values of the vertical components
of the entered loads (loads acting in GCS (-)Z-direction) to masses and
enter them as lumped mass data.
Note
This function does not convert self-weight
into masses. In order to convert self-weight into masses, “Converting
Type of Model Weight to Masses” in Model>Structure Type can be used.
Call
From the Main Menu select Model > Masses > Loads to Masses.
Select Geometry > Masses > Loads to Masses
in the Menu tab
of
the
Tree Menu.
Entry
Mass Direction
Assign applicable directions for the converted
masses.
Note
When considering the seismic effect (response spectrum analysis and time
history analysis using seismic data), the vertical mass component is usually
neglected because the lateral behavior is typically dominant. Thus, it
is common to select the X- and Y- mass directions. However, when considering the floor vibration
analysis, it is common to select the Z- mass direction because the vibration
mode in the vertical direction is the major mode.
Load Type for Converting
Select the vertical load types to be converted.
Gravity:
Acceleration of gravity
Load Case/ Factor
Load Case:
Select the Load Cases to be converted.
Scale
Factor: Enter a scale factor to be applied to convert the loads
to masses.
Note 1
The general methods of converting the structure
and the loads into masses are as follows:
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Mass Direction