from axisymmetric to 3D/symmetric model: correct loads?

[adlh]

I am trying to simulate a prototype on ANSYS in 3D. It has symmetries in the XY and ZY plane so I am only going to simulate 1/4th of the prototype. The prototype is an artificial lens. It has small 'legs' in the edges where it can be 'pulled', which is where the load will go. So the load is perpendicular to the axis.

The load is obtained from literature studies on the human lens. In these studies the load is usually reported as the total load required to stretch the lens by a certain amount in the x-axis, and values are from 0.08 N to 0.1 N. Usually these models are axisymmetric; I cannot do an axisymmetric model for my application because the 'legs' in the edges remove the axial symmetry.

In the 3D model, I wish to apply this load as a pressure on the surface of the 'legs', not a point force. My questions are 1) Should be pressure be calculated using the surface area for the application point in the entire model (the prototype's 4 legs), or just the 1/4th part that I'm modeling?

 

[ehp]

Hi,

Pressure is independent of surface area, so the numbers that you would calculate for the entire model and for the 1/4 section should be the same.

I suggest using a distributed force in the radial direction instead of a pressure. In this case, take the force from literature, multiply it by 1/4 of the circumference of your lens, and apply it to the 'legs.'

If there's a reason you must use a pressure instead of a force, you'll need to sum the surface area of the faces to which you intend to apply the pressure, and divide the force calculated above by this number.

Good luck,

ehp