May 16, 2013
11:04 a.m.
Hi Artem,
Instead of the second order equation:
Mx (d2u/dt2) + Cx (du / dt) + Kxu = Q.
I would use the standard trick to transform it to two first order equations:
du/dt = v Mx dv/dt = Q - Cx v - Kx u
Would that work for you? Otherwise some more advanced time-stepping scheme than the current backward Euler method would have to be introduced.
r.
On 05/16/2013 12:49 PM, Artem Sobolev wrote:
Hello.
Can you suggest how to SfePy set the second time derivative (with existing term or with new). The essence of the problem simple Mx (d2u/dt2) + Cx (du / dt) + Kxu = Q. This is a classical significance equation of motion mechanical system with damping. All my attempts to hurriedly add the desired derivative unaesthetic or ineffectual.
Artem Sobolev.