Calculation of normal and tangential overlap

If i understand overlap means contact then
1)use the command, not working properly till now.
compute pair/gran/local command
keyword = pos or id or force or torque or history or contactArea
2) calculate by defining a variable.
you know the position of two spheres.
it is straight forward to find the contact area
Samantaray

Hi TM,

Have a look e.g. at pair_gran_hooke_history.cpp

There is lots of literature on different DEM contact models, just search sciencedirect. One book I would recommend is Pöschel and Schwager: Computational Granular Dynamics, Springer

Cheers, Christoph

Hey
Can any one please tell me how to find delta_t (tangential overlap) required to calculate the "tangential spring force" ? Is it just enough to get the difference between the position vectors of the two particles in contact ? (or) how to calculate the normal and tangential relative velocities , from the existing dumped vx, vy & vz ?? I am doing all this to calculate the total energy dissipated during each contact. Please help.

Thanks & Regards
Anand

Hi,

have a look into tangential_model_history.h. The tangential overlap is calculated via a summation of the relative tangential motion during the whole contact.

Bests
Andreas

HI everyone
I have a problem during the torque measure through a screw conveyor, I want to calculate the torque around screw and when I use the tangential history,I get odd results and very noisy plot for torque. when I use tangential no_history and ignore the tangential overlap, I get cleaner more reasonable results, I want to determine the maximum torque for designing a suitable servo motor. which model is more reasonable for this ? can I ignore the tangential overlap or not ?