Rules Used for Generation of Mass Models
The following rules are applied by the program when the Mass Model Generator tool is used to create equivelant
- Only vertical load components are considered out of the selected loads.
Typically, these are loads parallel to the global Y direction. In the case of Z Up, these are loads parallel to the global Z direction.
- Only the user selected loads are considered, regardless of load item types and directions included in all load cases.
- Only load items in global or projected directions are considered. Any load item in the local direction (typically those labeled X, Y, or Z; e.g., uniform member loads in local coordinate directions) are ignored.
- Moment component of loads are ignored for generating equivalent gravity loads.
- Repeat and reference loads are expanded into a set of internal loads and the rules are then recursively applied to these.
- Additionally, some load types are ignored as they are not applicable to mass models. Please see the following table for additional details by load item category and load item type.
Category | Type of Load Item | Consider |
---|---|---|
Self-weight | Yes | |
Nodal Load | Node | Yes |
Support Displacement | No | |
Member Load | Uniform Force | Yes |
Uniform Moment | No | |
Concentrated Force | Yes | |
Concentrated Moment | No | |
Linear Varying Load | No | |
Trapezoidal Load | Yes | |
Hydrostatic Load | Yes | |
Pre/Post Stress Load | No | |
Fixed End Load | No | |
Physical Member Load | Uniform Force | Yes |
Uniform Moment | No | |
Concentrated Force | Yes | |
Concentrated Moment | No | |
Trapezoidal Load | Yes | |
Area Load | Area | No |
Floor Load | Floor | Yes |
Plate Load | Pressure on Full Plate | Yes |
Concentrated Load | Yes | |
Partial Plate Pressure | Yes | |
Trapezoidal | Yes | |
Hydrostatic | Yes | |
Element Joint Load | Yes | |
Solid Load | Solid Pressure Load | Yes |
Temperature Load | Temperature | No |
Strain | No | |
Strain Rate | No | |
Seismic Load | Seismic | No |
Time History | Time History | No |
Wind Load | Wind Load | No |
Wind Load Dynamic | No | |
Snow Load | Snow | No |
Response Spectra | Response Spectrum | No |
Repeat Load | Repeat Load | Yes |
Reference Load | Yes | |
Notional Load | No | |
Frequency | Rayleigh Frequency | No |
Modal Calculation | No |