Using FEA Structure and FEA Assembly to perform structural concept design

[Pedro Sequeira]

I have been using OpenVSP and the VSPAERO tool to design my wing to meet my requirements. I am now at a stage where I would like to design the internal structure of my wing to understand deflections and materials. I am trying to use FEA Strucutre to add the necessary subcomponents, such as ribs and spars, and FEA Assembly to merge it all together and create a mesh. I have multiple problems, which might turn out to not be problems, and aspects I dont understand:

1. If I add 2 assemblys, for example, my wing and my fuselage, each with some supcomponents, when I go into FEA assembly > Connections, nothing shows up. I think I should be able to establish rigid links here or connections between elements but maybe Im doing something wrong.

2. If I simplify the problem as much as problem, to a wing with just one spar and a rib, when I get to FEA Assembly and press Re-mesh All, 90% of the times it crashes (if there are more components then it 100% crashes).

Basically, the answer I am looking for is: Is this possible? If yes, can someone give me a guide or something, I have read these notes (https://openvsp.org/wiki/lib/exe/fetch.php?media=workshop23:structures.pdf) but they are too technical and dont answer all the questions I have.

Thank you,

Pedro

[Rob McDonald]

There are a bunch of bugs in the Meshing that were introduced in 3.33.0 or so.  They will be fixed in 3.37 -- which will be released Monday.  These will likely fix your crashes.  If not, form a specific test case and post it then.

Connections between assemblies are formed between fixed points.  In each Structure, add a FixPoint part and adjust as desired.  This will force that point as a mesh point.  It will also be numbered first (and in a consistent manner) and easy to find in the FEM file.

Then, when you go to an assembly, you can build connections by tying FixPoints in two Structures to each other.

Rob

--
You received this message because you are subscribed to the Google Groups "OpenVSP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openvsp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openvsp/2acb31d3-8f8f-49c0-857e-2e6741c246a4n%40googlegroups.com.

[Pedro Sequeira]

Hi, I have downloaded version 3.37 but I am still encountering the same mistakes. Maybe I am just doing something wrong.

1. I created a random example, in this case a wing and a stack:

2. In Analysis>Structure>FEA Structure:

2.1 In Strcture tab, I added both parts as structures.

2.2 In Part I added a spar and ribs to my wing and a slice to my stack (image for reference).

2.3 At this point I am not sure what I should do so I press "intersect and mesh" but this constantly crashes OpenVSP.

I don't understand what I am doing wrong.

My end goal is to carry out a structural analysis to understand how my system behaves under the aerodynamic loads to understand what supports I need and what not.