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7.8 WEB-BASED INTERACTIVE DESIGN OF BEAM-COLUMNS
The applet presented in this section is for
interactive design of beam-columns with various end conditions according to
the ASD and LRFD codes. This applet consists of four panels: Beam-Column Type (Fig. 7.7), Input
(Fig. 7.8), Results (Fig.
7.9), and Section (Fig. 7.10).
The user can select one of six different cases of beam-column types
presented in Table 7.1 plus one more case where the user can choose the end
moments (Fig. 7.11).
For type 7
beam-column, the user needs to enter the design K-value and to specify
whether the beam-column is a member of a braced frame or an unbraced frame;
i.e. frame braced against sidesway or subjected to sidesway (Fig 7.12).
Those two items are not active unless the user selects type 7. Likewise,
The user cannot change the design K-value for other types of beam-columns.
Depending on
whether the sidesway is inhibited through bracing or not, the applet checks
the design K-value given by the user and presents a warning message when
the user enters a value out of range (Fig. 7.13 and Fig 7.14). A similar
warning message will be presented when the user tries to run the applet
without specifying the design K-value for type 7 beam-column.
The applet displays
different input menus according to the beam-column type selected by the user.
For types 1 to 3, the design load consists of an axial load and a
distributed transverse load (Figs. 7.8 and 7.15). If the user selects the LRFD method as a design method,
the applet asks the user to enter the factored design load (Fig. 7.15). An
axial load and a concentrated transverse load at the mid-span comprise the
design load for types 4 to 6, and an axial load and moments at left and
right ends for type 7 as shown in Figs. 7.16, and 7.17, respectively. The
user can specify clockwise (CW) or counter clockwise (CCW) moment by
clicking on the choice list (Fig. 7.17).
The
user can select one of six different types of cross sections (see Fig.
6.14) and may or may not specify the nominal depth of cross section,
similar to the applet for design of axially loaded compression members
described in section 6.7. At this time, the applet has the following
limitations:
1. The member can be
subjected to bending about major or minor axis only.
2. The member can either
have full lateral support or no lateral support at all. Intermediate
supports are not allowed.
3. The effective length
factor is the same for bending in both principal planes.
4. The end conditions and loads acting on the member
are limited to those cases shown in the beam-column type panel shown in
Fig. 7.7.
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