move/mesh viblin command for a linear vibrator

Submitted by Misterblobby on Tue, 09/29/2015 - 01:13

Hi,

Can anyone help me to format the move/mesh viblin command to approximate a linear vibratory actuator?

These actuators can be approximated with a simple 1 DOF model Md2x/dt2 + cdx/dt + kx = Fsin(wt), where m is mass, c is damping and k is spring stiffness. >> Basically simple harmonic motion in one direction.

The axis, amplitude and period parameters are self-explanatory, but I'm not sure how to relate the phase parameters in the function back to the motion of the thing. I assume I need to use second order.

Thanks for your help.

Forums:

richti83's picture

richti83 | Wed, 09/30/2015 - 10:33

As the move-mesh command can not take the load of the mesh and particles which are in contact with it into account you would need a coupled DEM-MBD Simulation to achieve this where the vibratory actuator is modeled in an external tool (Modelica, SimulationX, Dymola, ...) and than coupled to LIGGGHTS(R).

I'm not an associate of DCS GmbH and not a core developer of LIGGGHTS®
ResearchGate | Contact

NTT1508 | Fri, 10/02/2015 - 05:38

Dear Christian,

My simple question is while we can assign properties to mesh/wall (particulate wall), it is currently impossible to consider interaction between mesh/wall and particles? Your DEM-MBD simulation on bucket motion looks really cool.

Thanks,

Regards,

richti83's picture

richti83 | Sat, 10/03/2015 - 13:40

it is currently impossible to consider interaction between mesh/wall and particles?
You can consider this interaction, BUT the wall-movement is only velocity controlled not force controlled. This means when you aplay a vibratory movement it will stay at constant frequence no matter how much load there is from the particles. What you need to simulate the influence of bulk solid onto an moving body is a force controlled movement and this implies to solve the differential equation under the boundary condition of a changing system-mass for every DEM-timestep. This is -of course- not implemented in LIGGGHTS mesh_mover.

I'm not an associate of DCS GmbH and not a core developer of LIGGGHTS®
ResearchGate | Contact

Misterblobby | Fri, 10/16/2015 - 00:29

Hi Christan,

Are you able to provide an example of how you would set up the move/mesh viblin command to vibrate at a certain amplitude and frequency?

A velocity controlled movement is fine, the frequency doesn't change much with load in this case.

Thanks.

xpt | Thu, 06/02/2016 - 21:20

Hi!
Did you work in this?
I'm interested to know because I'm working on something like that

Regards,