New question #271301 on Yade: https://answers.launchpad.net/yade/+question/271301
Hello everybody. Can anyone help me to understand the computation of relative shear displacement u_s in the interaction of 2 spheres via relative shear velocity u'_s as it's described in [Bourrier2013] (http://i11.pixs.ru/storage/1/6/6/picJPG_1860466_18763166.jpg): u'_s = O'_1 − O'_ 2 +(O_1 −C)xω_1 −(O_2 −C)xω_2, where O'_i - derivatives of spheres' center radius vector. ω_i and C - angular velocities and contact point in the timestep t + d_t. so as i understand the displacement u_s computes incrementally using small time step d_t, u_s = int_(0)^(d_t) u'_s dt = = (O_1 - O-_1) − (O_ 2 - O-_2) + ((O_1 −C)xω_1 −(O_2 −C)xω_2) * d_t, where O_i - is the coordinates of centers in step t + d_t, and O-_i is the previous position of spheres centers. the displacement u_s is a vector in the plane per-pendicular to the unit normal n of the interaction. So the vector ((O_1 −C)xω_1 −(O_2 −C)xω_2) * dt is per-pendicular to n because of (O_i −C)xω_i is a vector product and (O_i −C) is parallel to n. the trouble is that the vector (O_1 - O-_1) − (O_ 2 - O-_2) is not per-pendicular to normal n? So where i'm wrong in my consideration. with regard, Alexander -- You received this question notification because your team yade-users is an answer contact for Yade. _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
