calculation circle reinforcement tank filled with liquid

[TECNOMODEL]

also because that "technical values" is all to prove.

 

[ilmor]

if the problem was to determine the thickness of the wall (variable, obvious..) for which the material has a constant stress? Maybe between limiting deformations and limiting tensions you have to see the problem with two different approaches. .for simplicity considering "small shifts". .

 

[exxon]

That's a good question.

There is an analytical solution that passes through the solution of the differential equation mentioned in #10 and whose (partial) treatment is located at the link posted in #12.

in the case of a rectum cylindrical tank, all radial sections are identical and, unless a (important) discontinuity at the passage between wall and bottom, the equation provides a certainly usable answer.

different is the case of a reservoir of different form (as in the case of the parallelepipedo mentioned above). in this case, each section is different, and the differential equation would become partial derivatives, and its extremely complex solution, if not impossible.

you could trace thick profiles for a number of sections, solving the equation as if it were a cylindrical tank with that specific section, and then join the various sections with a kind of "loft". to the eye, the result should be good.

the numerical solution (finished elements) is probably the best one, but optimization could hide, even in this case, more than a bad surprise.

 

[TECNOMODEL]

beautiful philosophy, sin then that the reservoir must realize it.

 

[Fulvio Romano]

but at op (I saw that I learned?) still interested in the discussion?

 

[Fulvio Romano]

but is it not that the approach used until now is not the right one?
all this celolunghismo to partial derivatives is the least engineering approach that can exist. the engineer is the one who applies the engineer by solving a problem with the least commitment of resources possible.

set a partial derivative system costs salary hours. set a fem costs hours of salary and amortization of expensive programs and computers. at the end here is a plate (a side of the reservoir) bound on three sides that should not spread:
- the pressure distribution is known, the resulting therefore also
- considering what costs the iron, I make a supported-supported beam that resists a concentrated load in halfway equal to the resulting
- I find the profile on the market immediately higher
- I'm a caxxo containment cage with that profile.

Did I spend a little? Yes
Did I do it soon? Yes
Does it work? Yes

Rough and fast. Isn't that the engineer's work? or avoid getting into details when these are not necessary?

(*)
"Caxxo" in engineering terms of course. You know what I mean...

 

[stevie]

No, no, no, no, and no. polemic or not polemic, antipatic or non-pathetic... It's still not.

If you have a set of forces acting on a flexible system, you can't replace it with the resulting and think that the system behaves the same way.

These are so trivial things that if I try to explain it, it seems as if I took you for the melts.

I don't want to take you for the melts, but I don't even want them to pass as acceptable things that aren't.

I try: replacing a set of forces (two forces, but also a continuous distribution, as in the case in question) can be replaced by the resulting only if it acts on a rigid body!

You're an engineer, you did physics 1, this concept should be clear to you. If I invite you to go see him again, I'll call back to the direction, and then you know what? but yes, come on, we also apply the rigid body rules to flexible systems and we cheerfully cut off everything they teach in engineering.

Well, we put the band at 1/3 of the height. You're right.

be careful not to make confusion. . .
hydrostatic pressure follows a triangular pattern, but the pressure peak is obviously on the bottom! ! !
the famous "1/3" is linked to the fact that, in terms of balance of forces and pairs, the result of the distribution of hydrostatic pressures is equivalent to a force placed at 1/3 from the bottom.
not by chance if we look at a dam we realize that the maximum thickness of the construction is reached on the bottom.. .
said this to logic rigor, in consideration both of reasoning linked to the stresses, and for an aesthetic factor, I would opt for a double circle, one to the upper limit (it is however not advisable to leave the upper edge excessively fine and thin), and one in the half-carry, which, together with the intrinsic circle realized from the lower closing, should guarantee a good result.

 

[stevie]

but is it not that the approach used until now is not the right one?
all this celolunghismo to partial derivatives is the least engineering approach that can exist. the engineer is the one who applies the engineer by solving a problem with the least commitment of resources possible.

set a partial derivative system costs salary hours. set a fem costs hours of salary and amortization of expensive programs and computers. at the end here is a plate (a side of the reservoir) bound on three sides that should not spread:
- the pressure distribution is known, the resulting therefore also
- considering what costs the iron, I make a supported-supported beam that resists a concentrated load in halfway equal to the resulting
- I find the profile on the market immediately higher
- I'm a caxxo containment cage with that profile.

Did I spend a little? Yes
Did I do it soon? Yes
Does it work? Yes

Rough and fast. Isn't that the engineer's work? or avoid getting into details when these are not necessary?

(*)
"Caxxo" in engineering terms of course. You know what I mean...

good reasoning, moreover also a broken clock marks the right time twice a day.. .

 

[ilmor]

Yes, undoubtedly then practice is another thing, in the sense of realizing the tank.
The important thing, in my opinion, is to know how far from the actual conditions we go, making the object in a simple way. I believe that 90% of the common industrial machines are made so, and it is fine (relation: result / cost excellent.. )but in any case the concept must be clear, even if it "slows". ; )

 

[exxon]

I looked for the approach to the little movements you mentioned, but I found nothing about it. I found more documents dealing with the problem precisely with the approach of differential equation for elastic deformations cited in #10 and #23.

the most interesting are two papers, one of three researchers of the university of kraljevo (serbia) and the other of two researchers of the university of iași (romania). both treat the matter very similarly, then comparing the results with the fem simulation. not to say that they obviously treat only the case of the cylindrical tank.

here are the links:
https://www.researchgate.net/public...ndrical_tank_with_walls_of_variable_thickness
https://www.researchgate.net/public...lindrical_shells_with_variable_wall_thickness note: unfortunately the imagination makes reading some equations a real nightmare, but with some interpretation you can come to the end.

 

[Fulvio Romano]

good reasoning, moreover also a broken clock marks the right time twice a day.. .

what you write is wrong, both in substance and in attitude.
the purpose of the clock is to know the current time. so a broken clock is useless, even if twice a day marks the right time.

My reasoning, however, allows me to spend little time and few materials and achieve a result whose overall efficiency is very close to that achieved by developing a research project lasting a year.

forget this for pleasure instead of throwing there sentences without adherence to facts. I am not saying that in general this is the best attitude for the development of new technologies. I'm saying that wasting energy for a water tank goes against engineering practice.

 

[stevie]

I attach you a very explanatory picture of what I technically explained above.

this is a large tank with metal walls and reinforcements arranged symmetrically at constant pace (made by this company of Neighbourhoods). was filled with a liquid with constant density and in particular water.View attachment 53748the legend indicates that the effort of von mises and therefore the internal pressure generated by the fluid assumes values The Mass near the red areas and values minim in blue areas.
If you do not have discromy problems, you can see that the first third from the bottom of the wall is subject to maximum pressure due to the reaction on the horizontal bottom and reaction on the walls.

mecca but it is obvious the thing, the peak of hydrostatic pressure is on the bottom.. .
But to make fleas to the project if you look at the circles are arranged equispaced, wanting to use an analytical approach you should have concentrated in the area of the bottom and away more spaced to climb.

 

[Fulvio Romano]

mecca but it is obvious the thing, the peak of hydrostatic pressure is on the bottom.. .
But to make fleas to the project if you look at the circles are arranged equispaced, wanting to use an analytical approach you should have concentrated in the area of the bottom and away more spaced to climb.

the pressure peak is on the bottom, but the maximum sigma in the material is more up.
using the pattern of thin plates inflecting and binding it on three sides does not come out a trivial thing to solve.
using the beam model, however, the result is misleading because all problems related to transverse bending are not modeled.
the maximum voltage point (not pressure) is intuitively in the lower part, but understand where it is not banal. the fact that the resulting is applied to 1/3 does not play any role in what we are thinking about.

 

[ilmor]

I looked for the approach to the little movements you mentioned, but I found nothing about it. I found more documents dealing with the problem precisely with the approach of differential equation for elastic deformations cited in #10 and #23.

the most interesting are two papers, one of three researchers of the university of kraljevo (serbia) and the other of two researchers of the university of iași (romania). both treat the matter very similarly, then comparing the results with the fem simulation. not to say that they obviously treat only the case of the cylindrical tank.

here are the links:
https://www.researchgate.net/public...ndrical_tank_with_walls_of_variable_thickness
https://www.researchgate.net/public...lindrical_shells_with_variable_wall_thicknessnote: unfortunately the imagination makes reading some equations a real nightmare, but with some interpretation you can come to the end.

very interesting.
Thank you.

 

[stevie]

the pressure peak is on the bottom, but the maximum sigma in the material is more up.
using the pattern of thin plates inflecting and binding it on three sides does not come out a trivial thing to solve.

That's what I wanted to try to make you understand. . .
the analysis is traceable, as it has rightly mentioned exxon (I am a very objective person, and I recognize merits and demerits, beyond any pre-existing screes) to the resolution of a differential equation that in substance could be with good approximation lead to a simil equation of the elastic line.
alternatively analysis fem.

My consideration on the clock was that from your previous intervention, instead of showing an analytical and rigorous approach, you could perhaps show a somewhat "simplifying" attitude.
which from an economic point of view could bring problems. ..we want to make 1000 tanks a year, do you think that a fem optimization is not justified if it allows us to save material on each tank realized?
maybe those 1000-2000 euro needed for optimization analysis pay off after a few hundred tanks produced.

I'm sorry if you felt offended and wish you a good day.

 

[Fulvio Romano]

[cut] Maybe you showed a slightly "simplifying" attitude.
which from an economic point of view could bring problems. ..we want to make 1000 tanks a year, do you think that a fem optimization is not justified if it allows us to save material on each tank realized?
maybe those 1000-2000 euro needed for optimization analysis pay off after a few hundred tanks produced.

1. I'm solving the problem. optimize a tank.
2. if op (which in the meantime is forest uccel) wants to produce 1000 tanks per year and asks these questions better than let lose
3. if I have to make 1000 tanks a year and the analytical solution of a system of integrodifferentential equations with parametric coefficients tells me to use a sheet with variable thickness what do I do? Do I buy a business center? with 1000 pieces a year I have to use commercial profiles. the size of the commercial profiles usually follow a set of renards. split the hair and then double the size because the market that offers is one of the most frustrating things I know.

 

[TECNOMODEL]

but at op (I saw that I learned?) still interested in the discussion?

I don't think so, since it required a practical answer as a solution to a problem and the discussion, as often happens, has slipped into the philosophical.

 

[Fulvio Romano]

I don't think so, since it required a practical answer as a solution to a problem and the discussion, as often happens, has slipped into the philosophical.

dai...non tutti. . .

 

[TECNOMODEL]

dai...non tutti. . .

per fortuna.....

 

[PIETRO2002]

it is always worth the common sense, to use the sheet of the least possible thickness, weldable easily to hold and build around a frames using commercial profiles and maybe to predict on the bottom of the tubes to raise the basin with the bed and just if we want to add four higher ears for raising the tub with the chariot do not hurt.
I believe that without disturbing the grave, dear einstein, we can handle it in a short time. .