Building Loading - Deflection Conditions

(Revised:  11/15/2016)

 

The Deflection Conditions tab is used to establish deflection limits for designing frames and secondary members.  Deflection limits are dependent on the material or equipment being supported by BlueScope framing members.  Limits are specified by the Building Code, or if not, by BlueScope, AISC or MBMA serviceability limits.

  Note:  The software has a 1.05 allowance for deflection.

 

Deflection Information:

Frames are Vertically Supporting

This drop down list is used to define the material that frames will be vertically supporting.  Deflection limits will be generated based on the selected material.

Frames are Vertically Supporting - List

This list displays the vertical deflection limit specified per Building Code Requirements or the BlueScope standard for the specified material, the load case for each deflection limit, the Application factor to be applied to the load type, and the source of the deflection limit.

(Frame) Deflection Limit Override - V/

This edit box allows the system generated Deflection Limits to be revised. Note the deflection override will be applied to ALL system generated deflection load combinations whether more or less stringent.

 

Frames are Laterally Supporting

This drop down list is used to define the material the frames are laterally supporting, including cranes.  Deflection limits will be generated based on the selected material or the crane condition.

 

Load Sharing

Selecting a crane condition in the “Frames are Laterally Supporting” drop-down box will activate the “Load Sharing” option.  Select this check box when frame Load Sharing can be utilized and the building has cranes.  Load Sharing requires a minimum of one (1) bracing tier in the roof in every bay along the eaves of the building.  

 

  Note:  Load sharing applies to only concentrated lateral loads, not wind or seismic loads. 

Since the software cannot apply the counter-acting loads to account for load sharing, the software applies full lateral crane loads and then increases the allowable bare frame drift when the “Load Sharing” box is checked. Special review is required for cab-operated cranes with load sharing.

If counteracting loads are manually applied to account for load-sharing, do not check the Load Sharing box.

 

Frames are Laterally Supporting - List

This list displays the lateral/horizontal deflection limit specified per Building Code Requirements or the BlueScope standard for the specified material or crane condition, the load case for each deflection limit, the Application factor to be applied to the load type, and the source of the deflection limit.

(Frame) Deflection Limit Override - H/

This edit box allows the system generated Deflection Limits to be revised.  Note the deflection override will be applied to ALL system generated deflection load combinations whether more or less stringent.

 

Purlins are Supporting

This drop down list is used to define the material the Purlins are vertically supporting.

Purlins are Supporting - List

This list displays the vertical deflection limit specified per Building Code Requirements or the BlueScope standard for the specified material, the load case for each deflection limit, the Application factor to be applied to the load type, and the source of the deflection limit.

Purlin Deflection Limit Override - V/

This edit box allows the system generated Deflection Limits to be revised. Note the deflection override will be applied to ALL system generated deflection load combinations whether more or less stringent.

 

 

Girts are Supporting

This drop down list is used to define the material the Girts are vertically supporting.

Girts are Supporting - List

This list displays the horizontal deflection limit specified per Building Code Requirements or the BlueScope standard for the specified material, the load case for each deflection limit, the Application factor to be applied to the load type, and the source of the deflection limit.

Girt Deflection Limit Override - H/

This edit box allows the system generated Deflection Limits to be revised.  Note the deflection override will be applied to ALL system generated deflection load combinations whether more or less stringent.

 

Standard Controls:

§ OK, Cancel, Apply, Help

 

See also:

§ Building Loading - Building Codes

§ Building Loading - Live Load

§ Building Loading - Wind Load

§ Building Loading - Snow Load

§ Building Loading - Seismic