Emergent Problem with Millipede

I was learning this software alone. And I am testing a 2 point girder, like it in the attach.
I cannot change the load and load location.
Please tell me how to set the load and location of it.
Thank you so much!

Attachments:

1.png, 102 KB
2.png, 5 KB

Replies to This Discussion

Permalink Reply by Chris Tietjen on December 24, 2012 at 6:18am

My first look at this but for starters you can only apply a point load at a node of the system which you are not doing. I think you need to convert your point load to an equivalent linearly distributed load and input that into the L node of the FE component. Secondly even if your point load was located at a node of the system you're attaching it to the wrong input builder component.

Permalink Reply by maxleach on December 24, 2012 at 6:46am

Thank you so much for the fast reply!

What you meant is that I should use linear load instead of point load for that single line?

And I did not quite understand "even if your point load was located at a node of the system you're attaching it to the wrong input builder component." So which one shall I choose?

Thx

Permalink Reply by Chris Tietjen on December 24, 2012 at 8:11am

>What you meant is that I should use linear load instead of point load for that single line?

Yes. Use an equivalent linear load.

The applied point load has to be applied at an already defined node of the system. You can't just apply it somewhere in space.

If you were properly using a point load (which you're not doing in your current definition) you would input it at the M input in the System Builder component. You're currently inputting it into the 'Minc' input which sets the 'Minimum allowed length for a frame element'.

Permalink Reply by maxleach on December 24, 2012 at 10:24am

Thank so much for you reply in detail.

And I changed the components，like below.

But there is still a problem that it seems the load is still in the middle of the line.

And I used the "point between" to control the load position but it does not change,like in the 2nd picture.

Permalink Reply by Chris Tietjen on December 24, 2012 at 11:35am

Here I used two 'connected' lines to get the node for the point load.

Attachments:

9_MillipedeSimpleBeam.gh, 13 KB

Permalink Reply by Chris Tietjen on December 24, 2012 at 12:15pm

I posted the file again in case I forgot to internalize the curve data in the earlier attachment.

Attachments:

9_MillipedeSimpleBeam.gh, 14 KB

Permalink Reply by maxleach on December 24, 2012 at 6:50pm

Well, I do not know how to express my gratitude.

I put it into GH, and it works well. Now I began to apply it to more difficult

situation. Thank you!

Permalink Reply by maxleach on December 26, 2012 at 8:37am

First of all, why we use this pattern of support?

Secondly, why the point load is connected with FE System instead of

"L"(load) of the curve component?

Thank you so much!

Permalink Reply by Chris Tietjen on December 26, 2012 at 12:03pm

1) I thought that the X translation of the supports would need to be free to account for the axial shortening of the bar end points as the bar bends. However this doesn't seem to be accounted for in the output. There is no movement of the supports axially inward. RY is free to allow the ends to bend without inducing a moment at the supports.

2)The "L" (load) of the curve component is not a node (end point) of the curve system and cannot therefore take input from the Point Load component (at least to my understanding).

Keep in mind that it's very possible that I'm making mistakes with Millipede both in implementing it and in assuming how it should work. This is the first definition that I've tried to work through.

Permalink Reply by maxleach on December 26, 2012 at 10:10pm

Thank your reply.

So what you meant is that the "false X" means the supporting points can move along the X axis while it can also rotate according to the Y axis("False RY").

And I applied to another complexed structure.

But it did not work. I post it.

Attachments:

problem.gh, 18 KB

Permalink Reply by Chris Tietjen on December 27, 2012 at 2:45am

Yes. True means 'can't move'; false means 'can move'.

What are you trying to determine in this recent definition?

Permalink Reply by maxleach on December 27, 2012 at 3:50am

Yes, I am learning from your examples and trying to apply it to the structure post in the recent file, the more complexed one below. I post the grasshopper file.