Closed jerbaroo closed 4 years ago
If you add strains (or stresses) to the displacements than it is sufficient.
Displacement very close under pier settlement with Axis and OpenSees. Please ignore plotting alignment with Axis, will fix quickly with final plots.
Displacements are very close for pier settlement, strains not so much...
Oh me oh my, those are stresses in Axis.. but converting the OpenSees strains to stresses, by multiplying my E, would make them even larger
I will regenerate these plots, converting to microstrain first then converting to stress
In a plate loaded with a concentrated loads (inside a plate), if elastic plate theory is used (Kirchhoff-Love plate theory, Reissner-Mindlin plate theory) the stresses (strains, moments) under the concentrated load are infinitely large. So you should not try to compare them. You can also have singularities in other situations so if you observe non-convergence and highly concentrated stresses/strains then you can suspect a singularity in the solution.
You can cite this book as a support to this claim. https://www.cap-recifal.com/ccs_files/articles/cuveaqua1_denisio/Timoshenko_-_Theory_of_plates_and_shells.pdf
I do not follow. The shown ranges of the colorbars of the related pairs (Axis, OS) are not the same.
0.3 - 0.4 is the same yellow in the first two images (Axis, OS), 0.4 - 0.5 is the same orange etc..
The range for each segment in the colorbar is taken from Axis, and the colour
0.3 - 0.4 is the same yellow in the first two images (Axis, OS), 0.4 - 0.5 is the same orange etc..
Ok, I was mislead by the different ranges. Still, looking at the displacement plots from 1mm pier settlement, it is not entirely true.
The range for each segment in the colorbar is taken from Axis, and the colour
You could change the range in Axis manually, double click on the colorbar.
You could change the range in Axis manually, double click on the colour bar.
Yep, I used the "Round calculated values" option in there and then the contour plots seemed to line up a lot better. I noticed how it changes the values on the colour bar but exactly exactly what the option does is not documented.
Still, looking at the displacement plots from 1mm pier settlement, it is not entirely true.
Yes I didn't take the colour bar values for Displacement plots from Axis, because the OpenSees plots would then have out of range values, but now I think I will just stretch the range of the last colour segment to include those values.
On comparing Axis and OS: stop comparing the strains based on locations where you have strain concentrations (relatively small area with large strain and rapidly changing strain). The actual values are mesh dependent and very likely all singularities. Your model is good, show the convergence outside of the range of singularities and do not put sensors there (in most cases it would be also physically impossible), and you are done with the pier settlement. (same for stress)
convergencestrain-pier-settlement-4.pdf
The pier being settled is close to the edge on the south side of the bridge. Consider the bottom two plots in that PDF. The colour of each line increases from blue to red, as the distance form the center point of the pier is increased. Thus in the bottom two plots the strains seems not to converge as the point is passed where the piers connect to the deck. This is at 1.55m.
Plan for things to run overnight:
Once I have the data for the pier settlement convergence plot (tomorrow) I will send the convergence plots (I rewrote the whole pier convergence/plotting code last night so it should allow me to iterate on the plots relatively fast once I have the data). Combining that with the convergence information from the point load tests this should allow me to set where sensors are allowed to be placed, will look something like:
Plan for the weekend is:
Best bet is against Axis, Displace a pier by -0.1m and showing the values of the deck displacement. Do you think this is sufficient @rozsasarpi (do not reply on holiday)