I have a supplier that is proposing to change a large spot welded structure to laser welded. Structural issues aside, does anyone have any experience with volumetric inspection of laser welds (excluding x-ray)? Any suggestions on how to go about that? The sample provided to me shows a very...
todd2ny,
I presume you are using the common abbrev. for stainless.
If so the attached document may help.
Batman2http://files.engineering.com/getfile.aspx?folder=057e3cd7-b1e8-4c2e-b562-12a7da7ff33d&file=Stainless_Steel_fasteners.pdf
6060842,
Huck fasteners (pin and collar and BOM types) apply significant tension to the assembly. In fact, the tension is designed into the fasteners.
http://www.alcoa.com/fastening_systems/commercial/en/product_category.asp?cat_id=739
Yes, combined loading needs to be considered. Tension...
donsrno1,
Consider using hardness testing formulas..
http://www.calce.umd.edu/general/Facilities/Hardness_ad_.htm
Brinell Hardness Test
Brinell hardness is determined by forcing a hard steel or carbide sphere of a specified diameter under a specified load into the surface of a material and...
donsrno1,
I would conduct a simple small scale quasi-static test to start. Depending on the pressure distribution, amount, and the spacing of the "particles", gross deformation might also be of concern at 1mm of copper.
To measure the depth of the indentation after test, I would apply dental...
Screwman,
I fully agree with respect finding the actual torque. I'm basically looking a method to check for untighten nuts that have Loctite without damaging a properly installed joint. At this point, the supplier is experimenting as follows:
1) Measure torque required to break Loctite only...
6060842,
I would stick with hand calculations for the fasteners and then testing if the joints/loading in question is complicated.
There are many factors to consider that you may or may not capture in your model, it will only be as good as your assumptions. Unless you know all the details...
I have a situation that requires a supplier to "check" if a large (60mm) nut has been "tightened". Ideally, I would like to confirm installation torque (400 N-m), or at least something very close to that. The nut has Loctite 243 applied and is in a very tight space. I am concerned that damage...
SparWeb,
Good response!! If the damage is truly localized, could a flat doubler plate be used without excessive stiffness? If the double spans over the joint, it would also address the joint issue.
I would be in favor of testing a mock up repair for static and fatgiue strength, assuming...
Alexeu,
Not an aircraft type and there are details I like to know but....
1) Assuming the skin hardenable material like 5000 series AL, I would say no, it has been locally hardened by the cold working. If its a heat treatable alloy, there should be no change.
2) No matter how flat you think...
Jilwoodward,
EXACTLY right. You need to start somewhere considering the function of the joint, range of parameter, marigins etc. The torque-tension relationship is an estimate and must be treated as such when designing a joint.
If clamp load it must be known, the only way is to test the...
Yarsky,
Start with the following link:
http://mdmetric.com/fastindx/t28u.pdf
I suggest you follow Metengr's comment regarding grade selection.
Also, check the Industrial Fasteners Institute (IFI) manual Inch Fastener Standards There is a section on Corrosion medium vs. materials and plenty...
Diamondjim,
While turn of nut would seem to be a better approach, it too has issues (what doesn't..)
Take a look at the following discussion:
http://www.eng-tips.com/viewthread.cfm?qid=87855&page=1
Thread 87855
If the stiffness of the joint is relatively low, turn of nut will not provide...
Diamondjim and RJeffery,
I fully agree with your points except the twisting force, that too would be affected.
This is a typical formula used to estimate torque. Obtaining a proper value on friction alone is diffcult, The only thing that counts is bolt stretch. If you must know the clamping...
