STAAD.Pro Physical Modeler Help

Create Load Case dialog

This dialog is used to add a load case. Load cases can contain load items, include self weight, and reference previously defined load groups.

Opens when the Load Case tool is selected in the Loads group on the Model ribbon tab.

Control Description
Name Type a unique name for the load case.
Description Type an optional description to further explain the load case's purpose.
Category Select the nature of the load from the drop-down list.
Note: Load types with the term "definition" reference a load definition in the Catalog ribbon tab.
Analysis Set Select the analysis set with which you want to associate this load case.
Parameter Set (For "definition" load types only) Select the load definition to use. Only those relevant to the type selected will be listed here.

General Load Casess

SettingDescription
Self-Weight Data This factor is a multiplier for the calculated weight of the structural elements. A factor of 1.0 is used for the full weight.
Note: Time History, seismic definition, and response spectrum load types do not have any additional self-weight settings in this dialog.
SettingDescription
Multiplier in X Value for self weight acting along the global X direction.
Multiplier in Y Value for self weight acting along the global Y direction.
Tip: The self weight is applied in the positive global direction, so a negative value should be used for a typical gravity load.
Multiplier in Z Value for self weight acting along the global Z direction.
Load Group Filter Select one or more existing load groups from the drop-down list
Factors Enter a Factor for each load group selected using the Load Group Filter.

Wind Definition Static

SettingDescription
Factor

The factor to be used to multiply the wind loads. The factor is always positive and the direction is selected separately.

Direction Select the global direction in which the wind load acts.

Wind load sign conventions for Custom wind loads

Notes:
  • To see how these signs correspond to analytical wind load data, compare to the STAAD.Pro Wind Load help. Not Internal command is used in STAAD.Pro. Rather, it is interpreted as shown above.
  • For SP 16.13330 (Russian) wind loads, the factor sign controls the direction instead.
Internal (For custom wind definitions only) Set this option to indicate an internal, or suction, wind force on the surfaces (i.e., the load direction is reversed). If selected for a Russian wind load case, the Internal option is ignored but a warning message will appear when sent to the analytical model.
Open Structure (For custom wind definitions only) Option to be used if loading is to be generated on "open" type of structures. If not checked, then the load will be generated assuming the panels are "closed."
Russian Wind Options (For SP 20.13330 load definitions only)
SettingDescription
Oblique Select this option for wind loads to be applied at 45°.
Note: This option is only applicable for rectangular buildings.
Wind Pressure Coeff (Nu) Specify the wind pressure correlation coefficient. If parameter is omitted or is exactly 1, a computed value is used instead. For rectangular buildings, the correlation coefficient is always calculated automatically, thus any specified value will be ignored.
Assignment Select the Method to use for assigning the wind load to the building projection.
  • Automatic – No additional action required as the program will apply the wind load to the entire projection of the structure perpendicular to the selected Direction.
  • Specify Range – Type Maximum X/Y/Z and Minimum X/Y/Z global coordinates to limit the application of the wind load.
  • Groups – Click in the Group drop-down to select a previously defined group names.

Wind Definition Dynamic

SettingDescription
Factor Correction factor along specified direction.
Direction Choose an SP 20.13330.2016 wind load definition from the drop down list.
Oblique
Building Dimensions
SettingDescription
Perpindicular Length Effective projection of the structure facing the wind direction.
Parallel Length Effective length of the structure parallel to wind direction.
Options
SettingDescription
Allow All Mode Shapes Check this option to compute dynamic wind load vector for all mode shapes extracted from Modal Analysis provided it is within code stipulated frequency limit. When this check box is clear, the calculation takes only the first mode shape.
Orthogonal Loading
Ground Level Vertical coordinate of ground level. It should be defined in current input units. If not provided ground level is automatically calculated.
Static Wind Case Select a previously defined static wind load case from the drop-down list.

Seismic Definition

SettingDescription
Direction (For Seismic Definition only) Specify the direction for the load.
SettingDescription
Option Select the global direction in which the static seismic load is applied.
Factor Type a scale factor for the static seismic load case.

Snow Definition

SettingDescription
Group Select a predefined Group to which the snow load will be applied.
Condition Specify whether the load is Balanced or Unbalanced. These terms are described in section 7.6, and figures 7.3 and 7.5 of ASCE 7-02.
Roof Type
Specify the roof type from the available choices:
  • Default (if the roof type is not Mono, Hipped or Gable, it is referred to as Default)
  • Mono (see mono-sloped roof shown in figure 6-6 of the code)
  • Hipped (see figures 6-3 and 6-6 of the code)
  • Gable (see figures 6-3 and 6-6 of the code)
Roof Obstruction Specify whether the roof is Obstructed or Unobstructed. This also is a term described in section Table 7-2 of ASCE 7-02.
Roof Slope Factor Check this option for sloped roofs and then type the Value to use for the roof slope factor as described in section 7.4 of the SEI/ASCE-7-02.

Response Spectrum

SettingDescription
Direction (For Response Spectrum only) Specify the factors in each of the global direction for the response spectrum. Response spectrum loads can be applied in multiple directions (e.g., X = 0.7 and Z = 0.7).
SettingDescription
X Global X direction scale factor.
Y Global Y direction scale factor.
Z Global Z direction scale factor.

Time History

(there are no additional parameters used for a Time History load case)

Parent topic: Loading Ribbon Tab
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