# Member : Design Properties
These options are available for 1D members when the section material is steel. They define the properties relating to design from the interaction of the member with the rest of the structure.
# End restraints
End restraints define how the end connections of the member affect the effective length calculations. These are applicable only to 1D members.
The description specifies the degrees of freedom that are restrained by the connection. Individual rotational and translational terms can be restrained but the most common connections can be selected directly. These are:
- Pinned – top flange laterally restrained. Nominal torsional restraint. No restraint against rotation
- Fixed – encastre
- Free– no restraint
- Full rotational – top flange laterally restrained. Nominal torsional restraint. Both flanges fully restrained against rotation on plan
- Partial rotational – top flange laterally restrained. Nominal torsional restraint. Both flanges partially restrained against rotation on plan
- Top flange lateral
Custom – determine the detail of the particular connection. Note that inconsistent combinations of restraints will be automatically updated
# Effective Length
The options to determine effective lengths of 1D members are
- Automatic – uses only the member end conditions and the geometry of the structure to define the effective lengths in accordance with the design specification.
- Define the internal restraint on the member – both point restraints (where another member is connected) and span restraints (such as a slab on the top flange of a beam)
- Specify the effective lengths directly
The 'All Spans' drop down provides a shortcut to set the restraint condition for all spans along the member. The Advanced option allows restraints along individual spans to be specified.
The 'All Points' drop down provides a shortcut to set the restraint condition for all points along the member. The Advanced option allows restraints along at points to be specified.
Destabilizing Load
This is the height at which the load is assumed to act which can have a destabilizing effect on the member. By default this is relative to the shear centre, but can be relative to the top or bottom flanges.
Design Variable Overrides
These options allow selected variables in the design calculations to be overridden with fixed values. These options will be disabled if the chosen design code does not support the override.
# Note
GSA automatically detects and registers points and spans based on the nodes and elements along the member. When a Design Task is executed, GSA automatically generates the member internal restraints to assign point and span restraints. If the 'All Spans' member restraint is set to advanced the spans restraint conditions can be specified for individual spans. Likewise if the 'All Points' member restraint is set to advanced the spans restraint conditions can be specified for individual positions along the member.