help on simple analysis fem

[lorenzocalo]

Good morning to all, after searching on the forum I decided to write my first post. I have to do a very trivial fem analysis but I'm new to the industry that I'm experiencing difficulties. I can use both catia v5 and freecad.
I tell you the problem:
imagine a person lying on a cot (approximately with a semicilind). on the curved surface of the semicilindro (on the chest of the person) flows a belt type car seat belt. This belt is fixed on one side and is only tensioned on the opposite side. I should set something like this to understand the stresses on the person's chest at different levels of tensioning the belt itself.
Can you give me some advice?
Thank you all!

 

[meccanicamg]

What are you talking about? then we start from the fact that the human breast is not linear and is not assimilated to an isotropic material. manage an analysis according to the tensioning of the cingia, with constraint of the elastic mattress as well he does not linear, I would say that it becomes practically impossible without knowing the equivalent rigidity of the human body and the mattress. instead you could make a geometric pattern where you apply a tensioning force and break the useful force perpendicular to the chest. then you know the strength that you generate and with that you might want to make a nonlinear fem anyway doing as the first approximation that the mattress is rigid. However it is easier to get some analytical value than making a fem because there are too many unknown things. the human body is not a piece of iron.

 

[lorenzocalo]

Hello...thank you for the answer. of course the bed is to be considered indeformable; the non-linearity/isotropity of the human body does not bother me and I try to explain to you better what I need to understand from this analysis:
the goal is to understand how high to place the motor to achieve a distribution of strength that is the most centered on the chest possible, minimizing the side component that would tend to move the person to the bed sideways.

 

[meccanicamg]

Then you don't need a fem but you just need to make a geometric breakdown of forces. to vary the angle will vary the forces. If you do this with excel, use the solver and change angle so that your side force is minimal.