Stress Concentration problem in Ansys Workbench 15.0
Stress Concentration problem in Ansys Workbench 15.0
(OP)
Hey,
I got a problem with stress concentration after I applied a point force.
The tool has a fixed support at the half of the shank approximately.
Attached is a pic about the problem.
How to approach to fix that problem.
I got a problem with stress concentration after I applied a point force.
The tool has a fixed support at the half of the shank approximately.
Attached is a pic about the problem.
How to approach to fix that problem.





RE: Stress Concentration problem in Ansys Workbench 15.0
RE: Stress Concentration problem in Ansys Workbench 15.0
another day in paradise, or is paradise one day closer ?
RE: Stress Concentration problem in Ansys Workbench 15.0
By the way, I am using Tungsten carbide cobalt (10%) as a material.
RE: Stress Concentration problem in Ansys Workbench 15.0
how'd we solve this before we had models ? we'd make drill bits, and see how they worked, and learnt which designs worked and which didn't.
imo the best way forward is to model an existing drill bit in the material you're using to see what stress has been shown to be acceptable, then judge your stresses against this standard.
another day in paradise, or is paradise one day closer ?
RE: Stress Concentration problem in Ansys Workbench 15.0
Can I use a Moment instead of a force ?
Would it solve the problem and give good results ?
RE: Stress Concentration problem in Ansys Workbench 15.0
but it does raise another question about your analysis ... where is the load coming from ? how calculated ??
another day in paradise, or is paradise one day closer ?
RE: Stress Concentration problem in Ansys Workbench 15.0
Applying a radial force near the tip of the tool while fixing the clamp.
My question now, can I use a Moment instead of the force ?
RE: Stress Concentration problem in Ansys Workbench 15.0
RE: Stress Concentration problem in Ansys Workbench 15.0
Or was the load given in the problem description?
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Even if this is an exercise I'd be wondering what the material being cut thinks of being asked to provide this "point load". Like, how can I (the workpiece) generate a point load capable of inducing a principal stress over 80,000 psi.
Big loads suggest we may be talking about a heavy roughing pass, and that generally means "increased tool engagement angle" with the likelihood of significant length of tool edge engagement and even multiple tool edges.
http://www.conicalendmills.com/wp-content/uploads/...
Cutting tools generally show wear beyond a point. More like the left hand picture here.
http://lcamtuf.coredump.cx/gcnc/07-damage.jpg
RE: Stress Concentration problem in Ansys Workbench 15.0
why would you think to apply a moment (if you're intention is to apply a linear force) ? if this is a type of cutter, the cutting force is off-axis and so there is a moment induced in the part, but i don't see a moment being applied, not even a couple.
if you're analyzing a part, how do you know that 80ksi is no good ? even if it is above yield (or ultimate) it is not a real stress (if you're using a linear FEM). if it is higher than similar parts in service then maybe you've got a reason to question it.
another day in paradise, or is paradise one day closer ?
RE: Stress Concentration problem in Ansys Workbench 15.0
I tried to apply a force on a bigger area (many nodes together) as attached below.
Are the results logical ?
RE: Stress Concentration problem in Ansys Workbench 15.0
if you're looking for part failure, then the stress peak at the load application "should" be irrelevant, unless you're looking for the tip of the bit to clip off.
for a solid, I'd use von mises rather than max principal.
is the scale showing that the peak stress is somewhere else ?
another day in paradise, or is paradise one day closer ?
RE: Stress Concentration problem in Ansys Workbench 15.0
RE: Stress Concentration problem in Ansys Workbench 15.0
Only analysis through the contour colors.
Besides, I have the Transverse Rapture Strength (TRS) value (3700MPa), Poisons ration, elastic modulus and K1C only.
Can I compare TRS with von mieses to find the critical areas ??
RE: Stress Concentration problem in Ansys Workbench 15.0
i still think you're chasing phantoms if you're using linear FEA.
another day in paradise, or is paradise one day closer ?
RE: Stress Concentration problem in Ansys Workbench 15.0
I have a Brittle material (WC-10% Co), and I would like to see when it fractures. I have Transverse Rupture Strength value (3700 MPa).
Can I compare the Max Priciple Stress with TRS with ignoring Von Mises ??