weld calculation question

[Qluq]

Hi everyone,

i have to do some weld strength calculation with which i don't have any experience. i am using EN1993-1-8 to guide me, but i have 2 questions:

1. in section 4.5.3.2 item 6, can anyone tell me what gamma_M2 is, that is used in the strength criterion of a fillet weld?
2. in the same criterion beta_w is used. values are listed for steel types, but i have to calculate welds in a stainless steel structure. how can i find the beta_w values for AISI316L? or should I be using a different spec?

Thanks!
Mark

 

[desertfox]

Hi

This might help:-

http://www.bssa.org.uk/topics.php?article=147

 

[Duwe6]

It is a *lot* easier to design your fillets as a 'string'. This method is widely used, especially for structural - AISC items.

In Pound-Inch units, there is a handy combined constant of 928 lb for 70Ksi filler metal.

The strength of a fillet weld is 928 * [leg size in 1/16's of inch] * [Length in inches]
thus a 1/4" fillet weld [1/4" leg lengths, not throat, that is 11-inches long has a Design Strength of 928 * 4 * 11 = 40,700 lbs.

Note that this is not Yield or Tensile, this has the necessary derate to give a Safety Factor of 2, just like the BSSA calc uses.

 

[racookpe1978]

I have seen that approximation used, but only after the first 1/4 inch and last 1/4 inch of the fillet weld is subtracted off - as if the ends of the weld do not develope any strength.

 

[ukbridge]

1. Gamma_M2 is a partial factor applied to the resistance of the weld. The various numbers relate to various types of resistance, 0 for tension, 1 for buckling etc. They are all found in BS EN 1993-1-1, but should replaced by the decisions found in the UK National Annex. If you're using the UK National Annex for BS EN 1993-1-8, it is given as 1.25.

To use the Eurocodes successfully you (strictly) need to have a good overview of BS EN 1990, which outlines the philosophy of the Eurocodes. You can't really use one part in isolation.

2. The correlation factor, as far as I'm aware, is a fudge factor representing the fact that during testing fillet welds have been found to give sufficiently higher resistance than predicted using calculations models. These tests would only have been carried out on welds between materials that have been produced in accordance with specifications allowed by the Eurocodes. If you're not using any of the specifications in the table, you should use a Bw of unity.

 

[Qluq]

Thanks all!

Have been reading through the eurocodes and I think I'll be able to figure it all out.