Contrainte de roulements

21:04 Nov 5, 2017 

Thanks for the additional info.

It confirms that "charge de roulement" is a force pulling the buoy down, in order to oppose the force tending to bring the buoy up to the surface when the buoy gets plunged into rising water - the reason for the level of sea water rising being waves.

for a free floating object (density smaller than the density of the liquid) "la poussée d’Archimède" (basically the weight of the displaced water) gravitates around the weight of the floating object. But as a buoy is chained to the bottom of the sea, rising water level [caused by "le roulement" des vagues - there is nothing else around that would make the water rise] will plunge the buoy deeper into the water and increase "la poussée d’Archimède" pushing the buoy up and pulling on the anchoring chain with equal force (until the chain breaks).

I could elaborate a far more detailed explanations as an "exercice de style", by that's about the gist of it.

07:12 Nov 3, 2017 

Hi Nikki, and Daryo,

Thank you very much for your help and proposals.
Indeed I made a mistake writing contrainte instead of charge, sorry I was confused.

Here are some other extracts of the document.
Le flotteur est soumis à deux forces antagonistes : la gravité et la poussée d’Archimède. Cette dernière de par sa prédominance, pousse le flotteur vers le haut exerçant une pression sur la bride supérieure en équilibre avec la tension dans la ralingue.
La différence entre la flottabilité brute et la masse du coffre est représentée par la flottabilité nette, nous retiendrons cette valeur comme force interne appliquée sur la bride supérieure.
Dans cette note nous vérifierons :
Calcul de la flottabilité.
Les contraintes et déformations dans la bride supérieure.
Les contraintes et déformations dans les biellettes.
Le dimensionnement du câble interne et la ralingue.

And there is another picture of the same part.
https://imgur.com/a/qL0wR

15:51 Nov 2, 2017 

the only "roulement" in this ST that is relevant is "le roulement des vagues" which ends up cyclically pushing the buoy up and yanking the anchoring chain - THAT is a relevant factor: finding how strong the anchoring chain must be to avoid the buoy being swept away by the first storm!

there is nothing of the "roulement a billes" kind in this text so http://www.enr.fr/userfiles/files/Annuaires/Windustry-France... is completely irrelevant

the efforts generated on the buoy simply by "roulis / cavalement / tangage / embardée / lacet / pilonnement" (1) are not generated by a movement called "roulement" (2) are negligible - not a danger to the buoy.

Final clue in the coffin for any "alternative theory":

if you take a closer look at https://i.imgur.com/gxS3PJb.png

you will see that the ONLY "charge de roulement" mentioned is a force along the vertical axis pulling [the buoy] downward with 25 200 Newton of force

if you find any plausible alternative explanation as to what could be possibly pulling down the buoy with such force (enough to lift anything lighter than 2 1/2 tonne!) I'll buy a hat especially for the purpose of eating it!

10:27 Nov 2, 2017 

Could you provide a few juicy details on what is on the calculation note here. What appears before/after this term, for example?
Just seen the third JPG. Okay, so you have a load in newtons and three axes of movement. On your second image, you can see what part is being referred to.

Question: why do you use "contrainte de roulement" when the images uses "charge de roulements". Which is the term you require?
Might these even be about load of the "bearings" if that's what the part in piccie 3 is actually called.

See "main bearing" here, p136 of 400 and odd: http://www.enr.fr/userfiles/files/Annuaires/Windustry-France...

10:20 Nov 2, 2017 

"Rolling" can be used to describe one of the three possible rotational movements of a vessel (in the largest sense of the term) in water. In French, that term translates as "roulis". If "roulements" is describing the rolling movement of the buoy, I would be quite surprised. But I can sometimes be quite surprised!

FYI : http://www.thinkdefence.co.uk/ship-to-shore-logistics/increm...
https://lamisaine.jimdo.com/2016/04/03/mouvements-du-bateau/

Same termino for aircraft and also cars too, I believe.

That said, given the indication of movements around an axis on that third pic, it could well be describing the effect of load of the rolling movement of the buoy in the water - not the movemnt of the water itself, I'm almost certain. But why was "roulis" not used? Hmm.