Pressure and force directions

[Minh Chien Nguyen]

Hello,

I would like to know the pressure and force directions and magnitude in mofem config.

(?) apply a force = 2 on a point towards the x-axis

force_magnitude=1

force_fx=2

=> magnitude of force = force_magnitude * force_fx = 2?

=> force direction is well towards the x-axis?

(?) apply a pressure = 0.7

pressure_flag2=0

pressure_magnitude=0.7

=> pressure direction is towards the inside of body?

Is there a method (or software) to visualize these directions?

Thank you.

Best regards,

MCN

[ignat...@gmail.com]

Hello Minh,

MoFEM does not have a method to visualise forces yet.

This could be added in the future.

Pressure is applied in direction normal to body's surface. 

Positive defined pressure results to compression (inwards to body direction of force per unit area) and negative defined pressure results to tension (outward force per unit area).

Furthermore, forces are applied (within MoFEM) in opposite direction of the one defined in your input file.

For instance, when a force in your input file points towards the positive direction of x-axis, MoFEM "translates it" as a force pointing to the negative direction of x-axis.

All best,

Ignatios

[Lukasz Kaczmraczyk]

Hello,

If the fact that marker can be done easily, iterate over entities in BC meshsets and attach the tag to each of them. That will be visible in ParaView.

It can be done as a tool, that you take any mesh and VTK file is created with boundary conditions, that one can inspect what is going on. Would be an excellent tool for finding quickly why the model is not working. 

Regards,

Lukasz