Learning Forum

[valerym.m5]

Dear colleagues,

 

I am solving a dynamics problem (implicit solver).

I set the acceleration on the base of the part, changing according to the harmonic law.

The part should perform harmonic movements, but the part only moves upward.

Below are the graphs of vertical displacement for two points of the part (upper and lower).

I will be glad to receive your advice.

 

You can get the model from the specified link:
https://drive.google.com/file/d/1NlNCRUKt_v8xJjCql4Q8zPmE_34DxscK/view?usp=sharing

Regards Valery

[Reno Genest]

Hello Valery,

How do you apply the accelerationa and in which direction? Could you post the relevant LS-DYNA keyword? For example, the *BOUNDARY_PRESCRIBED_MOTION keyword?

Also, note that Ansys employees are not allowed to upload and download files on the Ansys Forum. Hopefully, other users will be able to look at your model and help you.

 

Reno.

[valerym.m5]

Dear Reno

Yes, you are right - I use two keyword

*BOUNDARY_PRESCRIBED_MOTION

 

See pictures below

 

[Reno Genest]

Hello Valery,

Do you have negative values in curve 3? So that the part moves up and down? Do you have other constraints that would prevent the part from moving down?

 

Reno.