verified grid

[AngeloB]

did you use the fem?. What kind of approach?

taking a little hand I would say that with inventor + algor in 2-3 you perform the verification.
Of course, if you could find an analytical formulation to be used in excel, it would be only a few minutes to pre-verify.

I also have very high values on the 7 mm bridge, but perhaps it is a mesh problem.

If the results are quite comparable, we could switch to the next step.
the crane mainly downloads a moment, I can not exploit any symmetries, I must model the virola and the teams that discharge on the currents.

I don't think you can solve the case analytically simply. in this case the fem becomes necessary? Do you have any calculations already made?

 

[gtemp]

I apologize to angelib having given an incorrect information about the part of the regulation rina rules for classification of yacht for commercial use to be consulted, it is the partb hull and stability and not the partd.
may also consult the partb of the rules for ship.
As for the calculation with excel there is a text, excel for scientific calculations and for engineers on which I have had a problem that can do to your case.
If you have patience I try to post it today to the maximum tomorrow.
Hi.

 

[Exatem]

I attach a sheet of excel still to the primordial state.
tomorrow, time allowing, I pledge to complete it and to improve it I also add drawings.
It's referred to a little raft for gums on a wooden boat.
take a look if according to you the calculation scheme is correct.

 

[AngeloB]

The excel sheet seems correct.

 

[Exatem]

The excel sheet seems correct.

I did it again.
Supposing the length of the beam is 1200mm and the order range is 1000.

Now it seems correct.
as soon as I can also attach the drawing

 

[Exatem]

next step.
I started putting on the sheet the sizing of the bridge. for today I only did the sheet (we hope without mistakes), tomorrow I do the rest.
p.s. the file name is temporary. more than verification you should call sizing.

 

[AngeloB]

Hello exa, as soon as I can control your new excel sheet.

I remodeled, simplifying and using only surfaces, a steel main deck.
I modeled the crane base and placed some stiffening team.
the bridge, near the base, is lowered by about 5 mm
I have no sense of tension peaks, probably mesh hurt, but the areas where the voltage of v.m. is above 100 mpa are small, and concetrated in easily structured areas.
summarizing: nothing is deformed in reality, but who is near the crane hears the bridge move while the crane is in manoeuvre, I must stiffen.

Can I show you the bridge model? Can I attach the dwf files? download the viewer from the autodesk site, it works well and you can insert notes.

 

[Exatem]

Hello exa, as soon as I can control your new excel sheet.

I remodeled, simplifying and using only surfaces, a steel main deck.
I modeled the crane base and placed some stiffening team.
the bridge, near the base, is lowered by about 5 mm
I have no sense of tension peaks, probably mesh hurt, but the areas where the voltage of v.m. is above 100 mpa are small, and concetrated in easily structured areas.
summarizing: nothing is deformed in reality, but who is near the crane hears the bridge move while the crane is in manoeuvre, I must stiffen.

Can I show you the bridge model? Can I attach the dwf files? download the viewer from the autodesk site, it works well and you can insert notes.

wait, today afternoon place the final version of the sheet.
In fact, if the moderator wanted to remove the precedents to avoid confusion. . .
Dwf files, I don't think I'll let you cheer them if you don't buy them.

You make me think of an episode.
the command of a ship of new construction called us because when they opened the salpancore the bridge seemed to rise.
It was certainly not an optical illusion, the shift was very evident.
taken the original drawings of the yard, we saw that missing any type of iron below and the winch was connected exclusively to the plate of the bridge.
we solved logically by adding the missing struttra.

 

[AngeloB]

can you view this file?
should be visible also directly in explorer, if you cannot try to download autodesk design reviev 2012

 

[Exatem]

this is the last version of the spreadsheet.
I also added another sheet to calculate the characteristics of composite beams.
If gerod or focus want, they can remove all previous files.
Bye.

 

[Exatem]

can you view this file?
should be visible also directly in explorer, if you cannot try to download autodesk design reviev 2012

Nothing to do angel.
during installation of autodesk design reviev 2012, a warning message that you can't download a routine and installation stops.
can you post it as an image or as a pdf?

 

[AngeloB]

you can do a pdf, but you lose the ability to see notes, view configuration and measure the model in 3d.
Can't even open it in explorer?
can I post a step directly.? !

 

[Exatem]

you can do a pdf, but you lose the ability to see notes, view configuration and measure the model in 3d.
Can't even open it in explorer?
can I post a step directly.? !

ok for the step. however a pdf I would do the same (for those who follow the discussion).
Bye.

 

[gtemp]

I would like to say something, but because the riforzo vertical instead of having a constant height does not stand taller in the central area, in practice as for the road bridge, on the supports has a height that as you go towards the center, where the bending is greater, you increase the height.
If I were the reinforcements of the bridge, I would do them like that.
I say stupid?

 

[pecos]

hi exa, first of all compliments for the work reported on the excel sheet!
I have tried to use it on my own application, very similar to the one mentioned in this discussion. I don't know if I'm wrong or there's a mistake in the spreadsheet, growing the degree of safety, reducing the thickness of the sheet.... .

 

[AngeloB]

I uploaded the files.

for gtemp, did you get to see the dwfx file? with explorer or design view?
I think that's how I'll strengthen it. They doubled the height of the currents that touch the virola and closed the virola with a ring.
the loads that the crane transmits to the base are:
vertical force=30 kn; = 80 knmt

 

[gtemp]

I uploaded the files.

for gtemp, did you get to see the dwfx file? with explorer or design view?
I think that's how I'll strengthen it. They doubled the height of the currents that touch the virola and closed the virola with a ring.
the loads that the crane transmits to the base are:
vertical force=30 kn; = 80 knmt

Yes, I downloaded the design view, gave it a quick look but I have to study it (not to judge but to understand).

 

[Exatem]

I would like to say something, but because the riforzo vertical instead of having a constant height does not stand taller in the central area, in practice as for the road bridge, on the supports has a height that as you go towards the center, where the bending is greater, you increase the height.
If I were the reinforcements of the bridge, I would do them like that.
I say stupid?

in the attached sheet, I have evidenced that in the case of first sizing of a bridge, the structure is represented by a beam on a x number of supports subject to a uniformly distributed load. In this case, since there is symmetry in both loads and constraints, you can “isolate” a part of beam between two consecutive supports. the segment of beams thus obtained can be considered as a beam stuck to the extremes under a distributed load. in this case the maximum bending moment is given to the incastries [(q*L^2)/12] while in the central section, the flender moment is half the maximum [(q * L^2)/24]. therefore in the total calculation our beam is a succession of maximum and minimal moments. logically for the dimensionalization I assume as reference the maximum bending moment.
there is also another less technical reason. building a beam that is an alternation of higher and lower heights, would be much more expensive than to adopt a commercial profile, of constant section (although in cases of local reinforcements you do).
for example the bases of the motor apparatuses, are made with a height greater than the rest of the paramezzale.
then why do you say that the bridges in the center have a greater section? to me does not seem (see photo)

hi exa, first of all compliments for the work reported on the excel sheet!
I have tried to use it on my own application, very similar to the one mentioned in this discussion. I don't know if I'm wrong or there's a mistake in the spreadsheet, growing the degree of safety, reducing the thickness of the sheet.... .

It can certainly be that there is one or more errors. Thank you if you report them to me to correct the sheet.
I'll check it out.
thanks to the signaling and compliments.
Hello, everyone.

 

[Exatem]

now should be correct, can you check?
It is not yet definitive. I'm adding some improvements.

 

[carry]

Hi.
Excuse me if I ask myself, with a question that does not center anything with the post in question, but it concerns the boat, I wanted to know your opinion given the experience in the field.
I have made mobile piers (which have been working for years) for the load of trajections, furniture because they have an altimetrica excursion of about 4 meters.
What I've never been able to clarify is this.
the trajectory arrives, leans on the poles, which keep the ferry from the pier, drops the pier and passes the means.
at this point the pier (with a camiom above) is almost supportive to the trajectory
for friction (it would be necessary to calculate the surface of the friction).
If there's a wave to the pier, how much does the trajectory drive against the bridge?
or what reaction should the pontile have?
Thank you.