When the bevel dimension and plate thickness are equal, as illus-trated in Figure 4-13b, the minimum fillet-weld size to de-velop the required effective throat in the web doubler plate i
Trang 1Revision and Errata List, March 1, 2003
AISC Design Guide 13: Stiffening of Wide-Flange Columns
At Moment Connections: Wind and Seismic Applications
The following editorial corrections have been made in the First Printing, 1999 To facilitate the incorporation of these corrections, this booklet has been constructed using copies
of the revised pages, with corrections noted The user may find it convenient in some cases to hand-write a correction;
in others, a cut-and-paste approach may be more efficient
Trang 24.4.2) and fillet-weld size There is both a strength and
geometric relationship that must be satisfied When the
bevel dimension and plate thickness are equal, as
illus-trated in Figure 4-13b, the minimum fillet-weld size to
de-velop the required effective throat in the web doubler plate
is:
When the bevel dimension is less than the plate
thick-ness, as illustrated in Figure 4-13c, the minimum
fillet-weld size to develop the required effective throat in the
web doubler plate is:
If a complete-joint-penetration groove weld is used, this
joint is generally not an AWS prequalified weld joint, but
can be successfully made with slight modification to the
following AWS prequalified weld joint designations:
(a) C-L1a or C-L1a-GF for web doubler plates that
meet the thickness limitation ( ) and
plate edges cut square
(b) TC-U4a (series) for plate thicknesses exceeding the
qualifications of (a) with beveled plate edges
The two primary deviations from the prequalified joints
are: (1) the root opening will exceed the maximum
toler-ance, assuming the plate width is selected to match the
T-dimension of the column; and, (2) the weld throat will
be slightly reduced, due to the flange-to-web fillet radius
As with a fillet weld, however, allowing a slight
encroach-ment into the flange-to-web fillet radius reduces the shop
labor required to make the weld by reducing the volume to
be filled The above practices are therefore recommended
4.4.4 Connecting Web Doubler Plates Along the Top
and Bottom Edges
When transverse stiffeners are not used and the web doubler
plate is extended past the beam flange or flange plate as
recommended in Section 4.4.1, there is no force to transfer
32
between the top and bottom edges of the web doubler plate and the column web This is also the case when transverse stiffeners are used and the web doubler plate
is extended past the transverse stiffeners as illustrated in Figures 4-4 and 4-5 In these cases, a minimum-size fillet weld per LRFD Specification Table J2.4 is used, except that the minimum size need not exceed the web doubler plate thickness minus
When transverse stiffeners are used and the web dou-bler plate extends to (but not past) the transverse stiffener, the joint between the transverse stiffener, column web and web doubler plate must be detailed consistently with the load path for the unbalanced force in the transverse stiff-eners Several common details are illustrated in Figures 4-11 and 4-12 The strength checks required for each of these details are illustrated in Examples 6-13 and 6-14
In Figures 4-11a and 4-12a, a CJP groove welded joint detail is used at the top and bottom edges of the web dou-bler plate(s) In Figures 4-11b and 4-12b, the joint details are essentially the same, except a fillet weld is first made connecting the transverse stiffener to the column web and the remaining gap to the web doubler plate is subsequently filled with weld metal In each of these cases, the result-ing joint can be used successfully on the thinner range of web doubler plates, say up to thick Beyond this thickness it is advisable to bevel the edge of the plate Although this adds to the fabrication costs, it will benefit the welder and increase the probability of making a sound weld In each of the details illustrated in Figures 4-11a, 4-11b, 4-12a, and 4-12b, one-quarter of the unbalanced force in the transverse stiffeners is transferred at each weld
In Figure 4-11c, a CJP groove weld is used to connect one transverse stiffener to the column web The web dou-bler plate extends to contact the transverse stiffener and
is fillet welded to it In Figure 4-12c, a similar detail is used with web doubler plates on both sides of the column web If the column web thickness is sufficient to trans-mit the full unbalanced force from the transverse stiffen-ers (Equations 4.4-2 and 4.4-3 can be used for this check), the fillet weld between the transverse stiffener and the web doubler plate is selected as a minimum-size fillet weld per LRFD Specification Table J2.4 Otherwise, the joint de-tail must be configured to transmit the portion of the un-balanced force in excess of the column web strength to the web doubler plate
In Figure 4-11d, the fillet welds on the right side connect one side of the transverse stiffener to the column web and the other side to the web doubler plate In Figure 4-12d, a similar detail is used with web doubler plates on both sides
of the column web In each of these details, one-quarter of the unbalanced force in the transverse stiffeners is trans-ferred at each weld
(4.4-7)
(4.4-8)
where
web doubler plate specified minimum yield strength, ksi
minimum web doubler plate thickness re-quired for strength per Equation 4.4-1, in
welding electrode specified minimum strength, ksi
Rev.