Percent elongation of a tensile test sample may not be best source. One needs a "True" stress-strain curve.
i.e. when a material reaches the Ultimate tensile stress, localized "necking" begins and invalidates the
true stress- true strain values after the ultimate is reached. Elongation...
It also depends on the geometry. If there is an notch in a component, hole or radius,
the stress and strain at the root of the notch can go plastic, say on first loading in
compression. Then when your overall nominal load returns to Smax the local stress at
that notch will be in tension...
Probably your "ultimate" stress is the same as "Yield" stress.
These plastics often neck down a lot and the neck propagates along
the length of the gauge section and has a completely different
cross sectional area after yield/ultimate. Was the cross-section area
measured after yield? or is...
A reversal refers to the change in direction of loading.
Thus there is a reversal at Smax and another at Smin,
so that in any given "cycle" there are two reversals.
If your estimated life is Nf= 5000 cycles, then that is equal to
2Nf = 10000 reversals.
A 0 to Smax loading may need...
Cycles to failure used to be the standard for plots and equations
before the 1950s. During the days of Coffin and Manson, there was a lot of
argument about how to incorporate the tensile test into the plot. Is it 1 cycle?
or a half cycle(reversal)? Makes a difference to curve fitting I guess...
Your part has a severe radius, much like a diametral test specimen.
I.e.: it is already "necked" from first load application.
One needs to apply Bridgeman's correction for necking.
See figure 1.10 in
http://libres.uncg.edu/ir/uncc/f/RomeroFonseca_uncc_0694D_10584.pdf
or search web for...
A few here:
http://fde.uwaterloo.ca/Fde/Materials/Alumcast/alumcast.html
Probably some more here:
http://www.werkstoffmechanik.tu-darmstadt.de/materials_database/index.de.jsp
The ultimate stress (Su) occurs at the point where localized necking
begins. If one places a diametral extensometer at the neck one
could follow the stress and strain beyond Su. It is not often done.
If you are not modeling localized component necking then the Su is
probably the best place to...
Assumptions: large structure, elastic analysis
1. Determine the no. of load input points or channels.
2. Collect the load histories for these channels.
3. Perform unit load analysis in FEA for each channel.
4. Software then determines simultaneous max and mins
across all channels. This...
If your spring element is elastic only it will not be possible
to observe a Bauschinger effect. For that you need plasticity.
If you model with a spring element in parallel with a frictional slider
you will get something like Bauschinger's stress-strain loops.
For the A572 try:
http://fde.uwaterloo.ca/Fde/Materials/Steel/Other/other.html
For the A283C its got higher Mn but
it appears that, according to
https://www.scribd.com/doc/103000868/Comparison-A36-A283-Gr-C
it is equivalent to an A36, which would lead one to web page...
Yes ncode, or any of the other two(?) use a similar scheme.
But its expensive per seat for the commercial codes,
and the process isn't really that difficult for a few elements.
I'm tempted to write an open source version.
In elements that are severely multiaxial, as observed in a
max/min principal vs angle plot, one cannot use von Mises or just a principal.
Best method is to divide the possible angles into 10 or 20 representative
cuts and then resolve the element stress history to stresses
perpendicular (plus...
Generally if one has a bunch of possible max principal stresses it
is best to create a plot of their values versus
their angle. As Corus recommends one must do this for both tensile and compression
principal stresses. The 2D plot of stress vs angle will usually show two
large critical...
Should be ok. A couple of limitations:
1. Not for fatigue. Single loading only.
2. Check the principal stresses too. -that they don't change
direction much during loading, if loading is multiple vectors
that are possible out of phase.
3. If the strains are huge in...
Try the explanations offered in N.Dowing's book
"Mechanical Behavior of Materials" 3rd edition
pg 469. Section 10.2.2: "Process Zone Size and
Weakest Link Effects" ISBN 0-13-186312-6.
Its a topic that is difficult to explain in a few
sentences here.
In my own view, unless you have some...
Probably ignore the zero,zero point in the stress vs plastic strain diagram.
The line goes upwards to the first point, but it is confusing. Probably due
to Ramberg-Osgood equation flaw. There is always a transition point where
one must "jump" from the elastic line to the stress vs total...
Not sure what you mean by adding the stresses together, but
total strain = elastic strain + plastic strain
For a given stress one can compute the
elastic strain = stress/E
and then subtract it from the total strain
to get the plastic strain.
It may be possible to work the formula No. 4 for Kc backwards and compute
the Fb or breaking forces of different test done in that reference. You
could then apply that force in your model to their geometry and compute the
stresses in the beam/tube. Q you can get from literature like...
