Part 2

Long 10 N  = Long10 fx –Long10 f max
                   Long10 f?- long10 fk

where f, and f, are the allowable stresses for 10’
and lox cycles respectively, as given in Tables
1 to

 d) Designating the expected number of cycles for
each stress level n1,, n2, etc. the element shall

be designed so that :

 n1  +   n2   +................n n  > I
N1       N2                    Nn

 5.3.3 Under no circumstances shall the basic
permissible stresses given in the relevant Indian
Standard Specifications for the particular type of
structure or lower stresses required by other clauses

in such standards be exceeded.

 5.4 Classes of Construction Details
In Tables I to 7 the values of allowable working
stresses are given separately for the classes of details

stated below:
Class A
Members fabricated with continuous full
penetration longitudinal or transverse butt
welds with the reinforcement dressed flush
with the plate surface and the weld proved
free from defects by non-destructive
examination, provided also that the members

do not have exposed gas cut edges.
Welds shall be dressed flush by machining
or grinding, or both, which shall be finished
in. the direction parallel to the direction of the

applied stress.

 b) Class B
(I)  Members fabricated with continuous
longitudinal butt welds with full
penetration made with either submerged
or gas shielded metal arc automatic process
but with no intermediate start-stop

positions within the weld length.

 (2) Members fabricated with continuous
longitudinal fillet weld made with either
submerged or gas shielded metal arc
automatic process but with no intermediate

start-stop positions within the weld length.

 NOTE - If a ‘stop’ should Accidentally occur m a weld which
is supposed to be free of start-stop positions, the weld crater
shall be chipped or machined back in the form of a taper
over a length of at least eight times the weld size, and the
weld shall then be restarted at the top of the tapered slope.
On completion, the surface of the weld at the start-stop position
shall be ground smooth. The object of this procedure is lo
eliminate the possibility of lack of fusion or trapped slag at
the weld root and a change of shape of longitudinal surface

profile of the weld.

 c)


Class c

 Members fabricated with continuous
longitudinal butt welds including fabricated
beams with full web penetration of the web
to flange welds, with start-stop position within

the length of the weld.

 d)

 Class D
I) . Members fabricated with full penetration
transverse butt welds made in the shop

by manual welding with electrodes other
than deep penetration electrodes, provided
that all runs are made in the down hand
position and that there is no undercutting.
This does not include welds made on a
backing strip if the backing strip is left

in position.

 2)

 IS 1024 : 1999
than deep penetration electrodes, provided
that all runs are made in the down hand
position and that there is no undercutting.
This does not include welds made on a
backing strip if the backing strip is left
in position.
Members fabricated with full penetration
transverse butt welds, other than those in
(l), and having the weld reinforcement

dressed flush and with no undercutting.

 3)

 Members with continuous longitudinal
fillet welds with start-stop position within

the length of the weld.

 e) Class E

 1)

Members fabricated with transverse butt
welds, other than those mentioned in
5.4(d), or with transverse butt welds made

on a backing strip.

 2)

 Members fabricated with full penetration

cruciform butt welds .







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Testing method

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