topic Re: Moving load in a circular pattern in Robot Structural Analysis Forum

Moving load in a circular pattern

Anonymous — Thu, 18 Jun 2015 13:16:32 GMT

Hello,

Today my question is how do I get the concentrated forces, I define in the moving loads, to point in the same place for example a center of circle?

In the picture I attached the FX force is pointing to the wrong direction.

Re: Moving load in a circular pattern

Artur.Kosakowski — Thu, 18 Jun 2015 14:41:38 GMT

The force will always be perpendicular to the route therefore you need to have large number of straight segments for the polyline.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

Re: Moving load in a circular pattern

Anonymous — Mon, 22 Jun 2015 11:49:04 GMT

I am designing a solid concrete cylinder which has moving loads at the top and its surface area. I was thinking of modeling it as a solid and using object type: shell. Problem is I can't apply moving loads to the cylinder object. Can someone tell me if there is a smarter way of doing this or how can I get the moving loads working?

Re: Moving load in a circular pattern

Rafal.Gaweda — Mon, 22 Jun 2015 12:36:30 GMT

I do not understand.

See example video:

Re: Moving load in a circular pattern

Anonymous — Mon, 22 Jun 2015 14:02:57 GMT

If you take a look at the picture perhaps you can then understand what I was trying to say. I can get the moving load working in a pipe sort of structure, like that video has, no problem.

Re: Moving load in a circular pattern

Rafal.Gaweda — Mon, 22 Jun 2015 14:15:10 GMT

DO not use ACIS objects.
Use standard ones

Re: Moving load in a circular pattern

Anonymous — Mon, 22 Jun 2015 16:13:32 GMT

Why does the program have them if one should not use them?

Re: Moving load in a circular pattern

Anonymous — Tue, 23 Jun 2015 08:01:17 GMT

@Artur.Kosakowski wrote:
The force will always be perpendicular to the route therefore you need to have large number of straight segments for the polyline.

I just realized that the suggested solution works when the concetrated loads are the same but is there a way to make the same thing happen with different loads?

Re: Moving load in a circular pattern

Rafal.Gaweda — Tue, 23 Jun 2015 08:17:35 GMT

?????????????
Please explain

Re: Moving load in a circular pattern

Anonymous — Tue, 23 Jun 2015 08:55:34 GMT

One load facing towards the center is 100 kN and the other is 200 kN which is also facing towards the center for example.

Re: Moving load in a circular pattern

Rafal.Gaweda — Tue, 23 Jun 2015 09:42:51 GMT

Artur's example used as a base:

Re: Moving load in a circular pattern

Anonymous — Tue, 23 Jun 2015 09:51:01 GMT

Sorry, I should've been more clear. I don't mean projections. A case where, there is another load for example 5 meters apart from the other.

Re: Moving load in a circular pattern

Rafal.Gaweda — Tue, 23 Jun 2015 09:58:56 GMT

Vehicle is always considered as straight.
So create manually number of simple cases with correct loads

Re: Moving load in a circular pattern

Anonymous — Tue, 23 Jun 2015 10:30:50 GMT

Alright, thank you.

I've got to ask you because this is really bothering me, how would you model a solid concrete cylinder?

We want to see moment results and we also want the self-weight of the cylinder to be correct. Also preferably structures that are connected to the cylinder are shell structures.

Re: Moving load in a circular pattern

Rafacascudo — Tue, 23 Jun 2015 12:06:58 GMT

Maybe you can try to vary the load using the route parameters.For each route(polyline) edge you can assign a load multiplier for each wheel on all 3 directions. It only works for symetrical vehicles

Re: Moving load in a circular pattern

Rafal.Gaweda — Tue, 23 Jun 2015 12:43:57 GMT

how would you model a solid concrete cylinder?

Re: Moving load in a circular pattern

Anonymous — Tue, 23 Jun 2015 13:11:57 GMT

What I mean by solid is that the cross-section is not hollow inside. If you could give and idea, how to model something like that would be great.

Re: Moving load in a circular pattern

Rafal.Gaweda — Tue, 23 Jun 2015 13:15:36 GMT

I am afraid I do not understand.
Any sketch, drawing please.

Re: Moving load in a circular pattern

Anonymous — Tue, 23 Jun 2015 13:21:20 GMT

@Rafacascudo wrote:
Maybe you can try to vary the load using the route parameters.For each route(polyline) edge you can assign a load multiplier for each wheel on all 3 directions. It only works for symetrical vehicles

Thank you for you suggestion but the problem is that the concentrated loads would change according to their place. They are supposed to remain the same no matter where they are for example in a case where the loads need to be in an exact order, so I guess the best resolution is the one Rafal gave.

Re: Moving load in a circular pattern

Anonymous — Tue, 23 Jun 2015 13:29:36 GMT

I am afraid I do not understand.
Any sketch, drawing please.

Maybe this image will help. Basicly like a column but so huge that it's best not to model it as a bar and because there are moving loads on it from different directions.