Net force on mesh

raguelmoon's picture
Submitted by raguelmoon on Tue, 11/16/2010 - 09:52

Hi Christoph,
I want to modify source code which can calculate net force on whole mesh moving in granular particles. That mesh is spherical type. Currently, we can measure force on triangles of the sphere. Can you give me some hints for doing this?
Thanks,
Ram

ckloss's picture

ckloss | Tue, 11/16/2010 - 09:57

you don't need to modify anything, its already there - have a look at doc for fix mesh/gran/stressanalysis

Christoph

raguelmoon's picture

raguelmoon | Tue, 11/16/2010 - 10:48

Hi,
In the doc pages, it is written as :
....the pressure and shear force on each triangle of the mesh is evaluated...
but I want to calculate total force on whole sphere (mesh) due to granular particles, not on each triangle of the sphere(mesh). I want to show that net force (on sphere) as function of time or height (of container in which the sphere is moving). Do you understand?
Thanks,
Ram

Ram

raguelmoon's picture

raguelmoon | Sun, 11/21/2010 - 13:07

Hi,
There are three force components on the mesh by output of fix mesh/gran/stressanalysis. Should I reduce these three vectors to one net force(scalar) or not? If I need net force along z-axis or total force on the mesh then what should I do?
Thanks,
Ram

Ram

ckloss's picture

ckloss | Sun, 11/21/2010 - 16:02

If you have the three components of the force and want the magnitude or the z-component, where is the problem?

Christoph

raguelmoon's picture

raguelmoon | Mon, 11/22/2010 - 06:08

Hi,
want magnitude...
Thanks,
Ram

Ram

schteppe | Tue, 07/05/2011 - 09:08

Hi, I am using mesh/gran/stressanalysis successfully - works great. I just need a clarification.. The total force on the mesh is output as a 3-vector, is this the total vector sum of forces? If I got a box with equal sized forces exerted on the center of each side toward the sphere CM, the output from stressanalysis will be zero, right?

ckloss's picture

ckloss | Tue, 07/05/2011 - 09:14

yes it is the sum

>>If I got a box with equal sized forces exerted on the center of each side toward the sphere CM,
>>the output from stressanalysis will be zero, right?
the time-average will be zero, yes

Cheers,
Christoph