We are welding plates and tubes with different thickness. While calculating the stress vs. strain, how should the area be calculated? Whether it should be for thinner member or for thicker member.
In another situation, how will the area be calculated if the thinner member has a higher Young's modulus and thicker one has lower Young's modulus.
The question been formulated too generally. The exact answer is possible if we set real sizes and mechanical characteristics of plate and tube for further numerical analysis. Although the possibility of prelimenary estimates of effective thermo-stressed area, based ob relatively simple formulae, is possible.
Dear Sushanta, As mentioned by Serge question is not specific enough for a straight forward answer. You cannot use simple addition or averaging because metal, heat effected zone and the weld will have very different composition and/or microstructure and therefore properties. But as a rule of thumb you can try to use "rule of mixtures", i.e., weighed average, i.e., add up the products of area fractions with the property value that you are interested in. Off course for a mechanical simulation whether the load application is perpendicular to or parallel to the weld, i.e., keeping the strain or stress equal during load application is important. Regards.
Thank you Prof. Bor and Serge,
for your kind suggestions. To further clarify the question as suggested, I have attached an image which represents a typical case. The weld pool is typical to any laser weld(more parallel to copper edge, curved on the ss edge). After welding, the dissimlar thickness metal do not remain completely unmixed at crown and root, rather they make a smooth transition in thickness. If we apply the load from the ends, and the stress is to be calculated, then which thickness/area do we have to choose and why?
Welding is not my expertize but as far as I can see you are forming a liquid pool consisting of Cu, Fe, Ni, Cr and then solidifying it to end up with a multiphase material, in which the composition and phase ratios are variable from point to point in the weldment. Since Cu and Fe are majority components and unsoluble in each other they will be the major phases. Most probably deformation and failure will ocur along Cu - weld interface of minimum area. To calculate yield or tensile strength you should use cross sectional area of that interface. And that will give you the strength of Copper, which you can read from a handbook. So still the question is not specific and clear enough.
good luck
regards.
with frequency response of piezoelectric transducer
if you have two different materials, and a welding point you have to consider the flexibility of the junction, so if you calculate the area of both materials.. you consider the youngs modulus of the materials..... what equipment are you using miscrsocopy.... dimentions of the materials ....... and the most importan you can use sensor or transducers
the young modulus of the welding point its importan
centimeters,,,nanometers milimeters what..??
I agree with Mr. Sakir Bor to some extent, but you should clearly check how you welded the dissimilar materials with different thickness? After that clearly check the macrostructure and then using tools in image analyzer you can judge the effected area and can caluculat the required mechanical properties
Best wishes,
Barla Madhavi
Thank you Jose and Ms. Madhavi,
we welded it with a CO2 continuous laser. All the weldings are full penetration mode, and the fusion zone is like what I have shown in the attached figure. Because the width of fusion zone changes from a minimum to a maximum, as we move from one metal to another, this slight confusion has arisen.
If it is longitudinally loaded, then should the tensile stress be calculated over the narrower area or an average(summated and divided) of the pool width.
regards.
Machine the specimen including the weld to have a uniform thickness and based upon your diagram machine to the same width. This done in welded tube sections of different thicknesses (AWS B4.0:2007 figure 4.4 page 9). Also check with ASTM 8 Standard Test Methods for Tension Testing of Metallic Materials.
Dear Sushanta ,
First you should decide what you want to determine and what for???
Above, correctly as a professional, Robert advises, the standard and best solution to your problem. But that solution gives the mechanical properties of the weld metal which is not homoogeneous along the length and width (not the weld itself).
So, you should formulate your question more clearly.
Regards
I apologize for the ambiguity.
I am welding dissimilar metal tubes(Cu and SS304). The OD for both is 19mm. But the wall thickness differs. For SS it is 2.2mm and for Cu it is 1.1mm. The welding has been done with a CO2 laser in full penetration mode. The image I have provided above is the longitudinal section of the weld.
I am doing tensile test as per ASTM standard A 370-14(section A 2.2), which is not very specific for tubes/pipes of small diameters. After going through Robert's suggestion, I found that the tests I am doing are as per AWS B4 (Fig 4.5) full section tensile testing. (ASTM 8 is generic for tensile testing of hard metals I think). I have load~displacement data in hand.
For calculation of tensile stress, I am a bit confused regarding the area to be chosen. Should it be the area of copper, which is the minimum, or should it be something else?
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