flag crane design with articulated arm

[Marcus990]

for calculation of the compound bending moment, obtained from bending and twisting the poncelet formula is used.
♪[ Mf_{id}=\frac{3}{8}Mf+\frac{5}{8}\sqrt{Mf²+Mt²}≈\sqrt{Mf²+0,75•Mt²} \]mf = flender moment
mt = torque moment

it is applied to beam elements with high flexional and torque loads. if there are pulsing stresses torsion fatigue and it has constant bending then 0.75 becomes 0.25.

being known the urge will use the reverse formula to determine what is missing:
♪[ \sigma_f=\frac{Mf_{id}}{Wf} \]with wf the form of the section.

I know, I'm very theoretical here.

First I would like to make you known that the ex cnr uni 10011 has been suppressed and therefore cannot be used for several years now. has been replaced by eurocode 3 uni en iso 1993-1-8, so what you are doing can only have academic value....but then let's not complain that students are not up to date. Alternatively you can use the technical standards ntc 2018 that are in auge in Italy and recalculate Eurocodes.
with regard to your beam, subject to bending/tortion that is a beam to catalog or that it is a welded compound does not change anything and in the post #10 there is the pattern taken from my dispensers that explains the use of the geometry of the areas, which is the basis of analysis a section composed with the use of the inertia section.

the problem may be of a different nature if you are studying the attack of the base of the pins because you start from the fact that you have a beam and calculations the macro reactions and macro internal actions but you are now working localized and therefore in a portion of material so small loses by definition the concept of beams and of all its accounts (trave: slender element with known section and almost constant).View attachment 61561as you can see, the structure was built with a boxed beam for all the slender and on that they did the bending accounts, twisting, cutting. then added a lower structural appendix to realize the bond and then to download the bending that turns into two horizontal forces for the attack of the pins.
View attachment 61562you may have as an alternative that to consider the h portion as a vertical beam even if it is actually a section far from something calculable by hand. definitely a fem analysis is ideal for studying that area that is too tough to follow laws of type beams.

certainly your tutor side university should support you and help you in these things, which is why it is called tutor.

Unfortunately, the fact that we are not up to date is true. consider that at perugia they are very theoretical and many things I have learned independently. only recently introduced a 3d design course. However, still far from the levels of polytechnics and the world of work.

 

[biz]

actually thinking about us well the formula of poncelet is valid only in case the solid has a circular section, quarry or full that it is, and it is easily demonstrable starting from the formula of von mises

 

[biz]

 

[Marcus990]

I understand, so what do you recommend to me for the cassone section where they work cutting, stinging and torque?

 

[biz]

the cut in primis I do not consider it,as trasurable, then at the most you will make for exercise a check to the cut, after the sizing.
I consider instead bending and twisting.there are several ways to proceed.
_estrapoli wfx from ix proportional iy to ix, for example impose the following condition:iy=0,7ix,
do it with criterion, however, that is to say that your section can be assimilated to two ipe or ipn beams (now desuete these last ones) approached and joined together you get first the moment of inertia on the two main axes of the aforementioned beams tabled through the huygens steiner theorem then impose the proportion and from there you have only one unknown that you will return.
_or hypothesize square moments always looking at the table profiles, choosing the most appropriate ones and checking the section, then you can always adjust the shot

 

[biz]

depends on whether you have to walk the analytical road or the pragmatic one

 

[biz]

maybe prepare a nice spreadsheet with excel or similar

 

[gerod]

not within the merits of formulas but what has been told is true: the cnr 10011 is dead but there are lifting equipment builders who still use it (we must not follow them!). to the face of industry 4.0!
the rules to use are 13001-x, if we really want to keep up with the times. if then your crane is light (under 10t of flow), use the en 16851 which is precisely for bridge and flag cranes.
Hi.

 

[biz]

I set the job.
see if you compare the values with yours, and if you ever have to use the attached file verify that the mounds have been written correctly and if you don't get something, let me know what control.

 

[biz]

the cut in primis I do not consider it,as trasurable, then at the most you will make for exercise a check to the cut, after the sizing.
I consider instead bending and twisting.View attachment 61564there are several ways to proceed.
_estrapoli wfx from ix proportional iy to ix, for example impose the following condition:iy=0,7ix,
do it with criterion, however, that is to say that your section can be assimilated to two ipe or ipn beams (now desuete these last ones) approached and joined together you get first the moment of inertia on the two main axes of the aforementioned beams tabled through the huygens steiner theorem then impose the proportion and from there you have only one unknown that you will return.
_or hypothesize square moments always looking at the table profiles, choosing the most appropriate ones and checking the section, then you can always adjust the shot

attention, I wrote in the formula an inaccuracy, as the torsion tau for a section of that kind is not calculated just so

 

[biz]

we say that if the section of your box is assimilar, with good approximation to a square or rectangular tubular even with variable thickness you can use the formula of bredt

 

[biz]

or if the shape is more similar to a beam type ipe I remember the following approximate formula:l the right for length of each rectangle

 

[biz]

But in the end your cuff will be closed so do the calculation test both with the formula of bredt and with the latter I posted.

 

[Marcus990]

hi biz, I heard my tutor and told me that I can use a rectangular tubular(which I can find from catalog) with over the flanges of welded pins. So the problem is easy to resolve, excuse me and excuse me all if I made you waste time. you were very kind and I saw that you are very prepared. I will not disappear, I want to be an active part of this forum and contribute with what I can to future discussions.

 

[PIETRO2002]

hi biz, I heard my tutor and told me that I can use a rectangular tubular(which I can find from catalog) with over the flanges of welded pins. So the problem is easy to resolve, excuse me and excuse me all if I made you waste time. you were very kind and I saw that you are very prepared. I will not disappear, I want to be an active part of this forum and contribute with what I can to future discussions.

no time loss indeed! however on such a structure a beautiful fem analysis would fit!

 

[danielllll]

good evening to all, my name is rotten and I am a mechanical engineering student at the last year of the master of perugia (address constructions). I am currently preparing an examination(advanced mechanical design) which includes as a practical part that to make the project of a lifting plant (in my case a flag crane with articulated arm cbb series). I began to set the isostatic scheme of the crane and to find the various diagrams (pending motion, cutting, normal and torque effort with arm "upside" placed at 90 degrees compared to that "tick side").
with regard to the embossed side arm (the one that holds the load) is a double t beam that I can find from the ipe catalogs (always referring to the most stressed point of the same), however for the bond side (the one attached to the column made in boxed cassone) I do not know how to dimensional it. the cnr-uni10011 legislation provided to us by the person who makes us mentor, however it is not clear as from the diagrams I have to dimensional a cassone beam boxed. I hope you can help me.
Thank you very much and I wish you a good evening and good Easter.

hi marcus I can have your project to understand things that I have to do thank you very much in advance

 

[meccanicamg]

hi marcus I can have your project to understand things that I have to do thank you very much in advance

And then we share the vote.

 

[re_solidworks]

hi marcus I can have your project to understand things that I have to do thank you very much in advance

a forum is made to share information, not to recover jobs already ready to use for your own purposes. so if you need a hand to perform this project and are willing to share it with this community, well come, otherwise avoid making such requests that have nothing to do with the purpose of this group.

 

[MassiVonWeizen]

a forum is made to share information, not to recover jobs already ready to use for your own purposes. so if you need a hand to perform this project and are willing to share it with this community, well come, otherwise avoid making such requests that have nothing to do with the purpose of this group.

@danielll opened a specific discussion on "his" project flag crane design with articulated arm but, like so many students who feel smart, having not received decisive answers, in the literal sense of the term, he thought of approaching a different method.

 

[danielllll]

@danielll opened a specific discussion on "his" project flag crane design with articulated arm but, like so many students who feel smart, having not received decisive answers, in the literal sense of the term, he thought of approaching a different method.

If I can't figure out how to do it, what can I show you?
I can't show you anything if I have nothing to do with it.