97
TABELA A3 – Categorias de tensões para o tipo e localização do detalhe de seções circulares
Adaptada de: AWS D1.1, 2008, p. 27
a
T = tension, C = compression, B = bending, R = reversal – i.e., total range of nominal
axial and bending stress.
b
Empirical curves ( based on “typical” connection geometries; if actual stress
concentration factors or hot spot strains are known, use of curve X
1
or X
2
is preferred.
c
Empirical curves (Figure 2.13, AWS D1.1) based on tests with gamma (R/t
c
) of 18 to
24; curves on safe side for very heavy chord members (low R/t
c
); for chord members
(R/t
c
greater than 24) reduce allowable stress in proportion to
Stress Category Situation Kind of Stress
A Plain unwelded pipe TCBR
B Pipe with longitudinal seam TCBR
B
Butt splices, CJP groove welds, ground flush and inspected
by RT or UT (Class R)
TCBR
B Members with continuouly welded longitudinal stiffeners TCBR
C
Butt splices, CJP groove welds, as welded TCBR
C
Members with transverse (ring) stiffeners TCBR
D
Members with miscellaneous attachments such as clips,
brackets, etc.
TCBR
D
Cruciform and T-joint with CJP welds (except at tubular
connections)
TCBR
DT
Connections designed as a simple T-, Y-, or K-connections
with CJP groove welds conforming to Figures 3.8-3.10
(including overlapping connections in which the main
member at each intersection meets punching shear
requirements) (see Note b)
TCBR in branch member (Note: Main
member must be checked separately per
category K1 or K2)
E
Balanced cruciform and T- joints with PJP groove welds or
fillet welds (except at tubular connections)
TCBR in member; weld must also be
checked per category F
E
Members where doubler wrap, cover plates, longitudinal
stiffeners, gusset plates, etc., terminate (except at tubular
connections)
TCBR in member; weld must also be
checked per category F
ET
Simple T-, Y-, and K-connections with PJP groove welds or
fillet welds; also, complex tubular connections in which the
punching shear capacity of the main member cannot carry
the entire load and load transfer is accomplished by overlap
(negative eccentricity), gusset, plates, ring stiffeners, etc.
(see Note b)
TCBR in branch member (Main member
in simple T-, Y-, or K-connections must
be checked separately per category K
1
or
K
2
; weld must also be checked per
category FT and 2.24.1)
F
End weld of cover plate or doubler wrap; welds on gusset
plates, stiffeners, etc.
Shear in weld
F
Cruciform and T-joints, loaded in tension or bending, having
fillet or PJP groove welds (except tubular connections)
Shear in weld (regardless of direction of
loading) (see 2.23)
FT
Simple T-, Y-, or K- connections loaded in tension or
bending, having fillet or PJP groove welds
Shear in weld (regardless of direction of
loading)
X
2
Intersecting members at simple T-, Y-, and K- connections;
any connection whose adequacy is determined by testing na
accurately scaled model or by theoretical analysis (e.g.,
finite element)
Greatest total range of hot spot stress or
strain on the outside surface of
intersecting members at the toe of the
weld joining them-measured after
shakedown in model or prototype
connection or calculated with best
available theory
X
As for X
, profile improved per 2.20.6.6 and 2.20.6.7 As for X
X
1
Unreinforced cone-cylinder intersection Hot-spot stress at angle change; calculate
per Note d
K
2
Simple T-, Y-, and K-connections in which the gamma ratio
R/t
of main member does not exceed 24 (see Note c).
Punching shear for main members;
calculate per Note e
K
As for K
, profile improved per 2.20.6.6 and 2.20.6.7