The design of composite columns is seamlessly integrated within the
program. Initiation of the design process, along with control of various design
parameters, is accomplished using the Design menu. Automated design at the
object level is available for any one of a number of user-selected design codes,
as long as the structures have first been modeled and analyzed by the program.
Model and analysis data, such as material properties and member forces, are
recovered directly from the model database and are used in the design process
in accordance with the user defined or default design settings. As with all
design applications, the user should carefully review all of the user options and
default settings to ensure that the design process is consistent with the user’s
expectations. Composite column design options include the
use of the Direct Analysis Method. The software is well suited to make use of
the Direct Analysis Method because it can capture the second-order P-Δ and P-
δ effects, provided the user specifies that a nonlinear P-Δ analysis is performed.

For each design combination, composite column members are checked at a
number of locations (stations) along the length of the object. The stations are
located at equally spaced segments along the clear length of the object. By
default, at least three stations will be located in a column or brace member. The
user can overwrite the number of stations in an object before the analysis is run
and refine the design along the length of a member by requesting more
stations. Refer to the program Help for more information about specifying the

number of stations in an object.

The code requires that stability shall be provided for the structure as a whole
and for each of the elements. Any method of analysis that considers the influence
of second order effects of P-Δ and P-δ , geometric imperfections, out-ofplumbness,

and member stiffness reduction due to residual stresses are permitted by the code. The effects of geometric imperfection and out-of-plumbness
generally are captured by the use of notional loads. The effect of axial, shear
and flexural deformations and the effects of residual stresses on the member
stiffness reduction has been considered in a specialized method called “Direct
Analysis Method.” This method can come in different incarnations (formats)
according to the choice of the engineer as allowed in the code.


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