Cálculo Solda Filete
Cálculo Solda Filete
Cálculo Solda Filete
CBE-11.1
ISSUE DATE 05/83
REVISION DATE 9/1/99
PRAXAIR, INC. WRITTEN BY F.J. Szinger
PRAXAIR TECHNOLOGY CENTER REVISED BY E. P. Golebiewski
TONAWANDA, NY 14150-7891 APPROVED BY E. P. Golebiewski
1.0 SCOPE
This design guide covers the shear strength of fillet welds of materials frequently used in cold
box design.
2.0 DISCUSSION
This standard is intended to be a time saver in sizing fillet welds which are in shear loading.
Although weld filler metals may be stronger than the items welded, it is assumed here that fillet welds
are only as strong as the weaker of the metals or alloys welded. The welded joint could fail right next
to the deposited fillet. Therefore, when two alloys of different strength are joined by a fillet weld, the
weld strength is based on the weaker of the parts joined. Also, the weld strength is based on the
temper of the alloy at the weld condition.
According to the American Welding Society, the allowable load on fillet weld is defined as
follows:
F = 0.707 L x T
Where:
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Guideline CBE-11.1 (Revised 09/01/99)
The ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 defines the allowable
load on fillet welds in Section UW-18 as follows: "The allowable load on fillet welds shall equal the
product of the weld area (based on minimum leg dimension), the allowable stress value in tension of
the material being welded, and a joint efficiency of 55 percent.
These two methods are compared to see what difference there is. Let ft equal the allowable
stress value in tension. The ASME Code defines the allowable shear stress of alloys as 0.80 ft. For
given fillet size, the allowable shear load per linear inch of weld would be
Thus it is seen that using the ASME method of calculating the allowable load on fillet welds is
slightly more conservative than the AWS's method. Also, since many of the fillet welds designed by
cold box engineers are for pressure vessels, and many of the alloys welded are listed in the ASME
Code, it is more convenient to size fillet welds by the ASME Code method. Some of the fillet welds
on vessels and packages are subjected to some fatigue loading during shipping. For these reasons, size
fillet welds by the ASME Code method.
The following table lists allowable loads for fillet sizes for the most commonly used alloys.
These allowable loads are based on the ASME method.
Carbon and
Min. Fillet 3003 Al 5083 Al Welded 6061 Al Stainless Steel
Leg Size, In. ft = 3300 psi ft = 10,000 psi ft = 6000 psi ft = 13,800 psi
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Guideline CBE-11.1 (Revised 09/01/99)
REFERENCES
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