topic Re: Frame analysis glitch in Inventor Forum

Frame analysis glitch

yta10 — Mon, 21 Aug 2023 22:00:53 GMT

Hello

Do you think there is a glitch or I missed something.

I found out the reaction forces on constrains show inconsistent values.

1) I read values of axial force on number 1 value.

2) the reaction forces on all nodes follow value of number 1.

3) and I read beam diagram again, and see reaction value of number 2.

4) the rest of reaction values all follows the value of number 2.

What is the solution for this? and is this glich?

Thank you

Re: Frame analysis glitch

JDMather — Mon, 21 Aug 2023 23:54:58 GMT

@yta10

Attach your assembly here.

Re: Frame analysis glitch

Gabriel_Watson — Tue, 22 Aug 2023 00:16:15 GMT

What constraints did you place on number 2? Perhaps fixed isn't the correct one for this analysis. You would need to show all the settings or share files to confirm.

Re: Frame analysis glitch

yta10 — Tue, 22 Aug 2023 00:35:12 GMT

Thank you so much!

I would like to share my files, and I have more questions.

The constraints are all pinned constraints.

I designed frames so that nodes can be shared at one node locations, thinking that I could remove rigid link, which may make model simple, and easy to modify release.

I did experiment on releases.

1) Column release.

I release columns so that top column can have xxxffx, and column at the bottom has xxxxxx.

but still the node that has xxxxxx is pined with pin contraint.

I notice moment Y is 0.

I see only reaction force in Y.

2)Beam release

I released nodes on the beams. xxxffx-xxxffx. I noticed I see moments at the nodes, but I don't want to see the moments at the nodes, because I want to regard nodes as pinned connection as in bolted connection.

I see reaction forces in all transitions.

3)I released column and beams. in this case I don't see moment y. the displacement was the largest, compared to the previous cases. I see transitions in Y only

1)What is the correct way to run this analysis when it comes to release. Am I supposed to see reaction forces in other directions other than Y?

2) I still have the reaction force glitch I described.

Re: Frame analysis glitch

ytakko1004 — Tue, 22 Aug 2023 21:50:34 GMT

Thank you.

I attached my file on my reply

Re: Frame analysis glitch

ytakko1004 — Tue, 22 Aug 2023 21:51:08 GMT

Thank you. I used pin constraints. I attached my files.

Re: Frame analysis glitch

johnsonshiue — Tue, 22 Aug 2023 23:57:14 GMT

Hi! I took a quick look. I could be wrong but the structure looks very unstable to me. The pin constraints do allow the connection to move. Essentially, the be structure can fall to the ground based on the given constraints. Either more frame members are needed or more restrictive constraints are needed.

Many thanks!

Re: Frame analysis glitch

JDMather — Wed, 23 Aug 2023 11:15:10 GMT

Tip:

When using Pack and Go - do not need Design Data (usually), OldVersions, or Templates...

Also - you should install the latest Update available for your version of Inventor.

What is the purpose of Pinned Constraints 5-8?

Re: Frame analysis glitch

ytakko1004 — Wed, 23 Aug 2023 20:18:53 GMT

Hello

Thank you for your reply.

and I will delete those folders next time.

So this could be the description of the constraints.

the beams are bolted down on to a fixture on a concaved structure.

the columns are bolted on lugs at the bottom.

the constraints 5-8 are the fixture connections.