Breast vibration model

[Koenvantuijl]

Hello,

I am working on my project on the dynamic modeling of a female breast. I want to model the vibration of a breast after a sudden vertical displacement, (think small jump).
The project thus far is included in the link.
Up till now I enforced the boundary conditions on the backsurface as being entirely prescribed: no displacement in the x,y direction and a parabolic trajectory (again think jump) in the z direction.
So the entire backsurface remains planar and rigid for the whole duration of the simulation. I am starting to doubt this assumption and looking for "more realistic" ways to encorporate boundary conditions in my model.
I could ofcourse only enforce the boundary conditions on just a selectful amount of notes and not on the entire surface and let the breast "carry itself" more, or I could tie the breast to some rigid with some kind of contact, and then force the trajectory on the rigid object. I am not sure what approach I should take can anyone give me some advice, what would be appropiate?

any insights are appreciated,

Thanks in advance,

Koen

[maas]

Hi Koen,

What about your current results made you decide that it's not realistic enough. My two cents on this, is that I assume that the breast is attached somehow to the rigid ribs underneath it. So, I don't think your setup is entirely unrealistic. You could perhaps consider modeling more of the pectoral muscle and attach the back of that muscle to the ribs, but not sure if that will make a big difference.

Best,

Steve

[Koenvantuijl]

Hi Koen,

What about your current results made you decide that it's not realistic enough. My two cents on this, is that I assume that the breast is attached somehow to the rigid ribs underneath it. So, I don't think your setup is entirely unrealistic. You could perhaps consider modeling more of the pectoral muscle and attach the back of that muscle to the ribs, but not sure if that will make a big difference.

Best,

Steve

Thank you for your quick reply, I was dissatisfied with the following result of comparing "nipple displacement in the z direction " again real life data. See the attachments, as you can see real breasts act as a much stiffer spring below equilibrium than above: the displacement below zero is only fraction of the displacement in the model. After I have given this some more thoughts I think it indeed has nothing to do with any boundary conditons. After doing some more research I think this may be related to the presence of Cooper ligaments, that are not yet included in my model. "Cooper ligaments are the fibrous connections between the inner side of the breast skin and the pectoral muscles. they are largely responsible for maintaining the shape and configuration of the breast. They play a major role in preventing breast sagging". I included a picture as well. Could this effect be modeled as a fiber? I am going into new territory here and would grealy appreciate any directions I can get.

regards,

Koen