Recent Posts

31

Analyzing & Optimizing Stiffened Panels / Hat Bonded Smeared Panel Sizing

« Last post by loganbthomas on July 15, 2021, 08:39:17 AM »

I am using the Hat Bonded Concept using the detailed sizing, smeared panel approach. I've been looking at the weight differences when using various numbers of stringers in the skin bays. For example: 1 stringer, 2 stringers, 3 stringers, and 4 stringers in the bays. It's my understanding from reading the HME documentation for smeared panels that for Hypersizer to understand how many stringers are effectively in the bay using the smeared panel approach I should divide the appropriate buckling span by the number of stringers and input that value in the Spacing dimension for the Hat Bonded Concept. Is this approach correct?

In addition, after looking through the HME documentation for Geometry Cross-Section Checks it looks like for the smeared panel analysis to be considered valid there needs to be 3 stringers in the bay according to Geometry Rule 40. Does this mean that even though I input the Spacing dimension such that there should be 1 stringers, 2 stringers, or 4 stringers that Hypersizer will still analyze the bay as if there were 3 stringers?

32

Scripting / Re: How to create new component via VBA? No ComponentCol.Create method exists.

« Last post by James on July 08, 2021, 07:54:27 AM »

There is not a 'create component' method. Creating and editing component membership touches too many database tables.

A work around is to create assemblies, by element, through the FEM viewer > Assembly > Create multiple assemblies by specifying input files...

The input files can be comma-separated lists of elements. A unique assembly will be created for each input file selected. When elements that are members of the same component are split into multiple assemblies, new components are created to enforce the rule that components can only live in one assembly. After this process is run you could reassign the new components to the original assemblies using the VBA script.

I hope this is helpful.

-James

33

Analyzing & Optimizing Stiffened Panels / Re: FEA Loads - Peak Element Filtered

« Last post by James on July 08, 2021, 07:45:30 AM »

I'd like to add that the peak element processing is repeated for every unique thermal set and/or assigned reference temperature. So if you have 2 unique thermal sets, then you get two blocks of processed peak element forces. During sizing, both blocks are checked.

I hope that's helpful.

-James

34

Miscellaneous Software Topics / Re: Stiffness Requirements File in General FEA Constraints

« Last post by BStier on July 08, 2021, 07:35:51 AM »

Hello oyama,

you can use the "Stiffness Requirements File" in Express by defining the file path in the: Analysis Criteria -> Stiffness Criteria dialog.

This way, you can define a minimum required stiffness (ABD matrix diagonal) for every individual element in your model.

The file format is as follows:
___________________________________
-1
#of Entries (i.e. number of elements you want to define a stiffness target for)
ElId, [dummy], A11, A22, A33, D11, D22, D33
…
-1
____________________________________

A simple example file defining the minimum (required) stiffness for elements with ID 1 through 10 is attached to this post.

Now, during element sizing optimization, these minimum stiffness requirements will be fulfilled (if your design restrictions allows for it; e.g. if max gauge is high enough for your chosen material).

I hope this helps!
-- Bertram

35

Miscellaneous Software Topics / Stiffness Requirements File in General FEA Constraints

« Last post by oyama on June 14, 2021, 02:17:02 AM »

Hi,
How can I define "Stiffness Requirements File"?

I use Express for sizing composite structure, and I try to optimize with respect to the stiffness(Nodal deformation), but I don't want to use iteration. Then, I try to define "Stiffness Requirements File".

Any help would be welcome.

Sincerely,

36

Analyzing & Optimizing Stiffened Panels / Re: FEA Loads - Peak Element Filtered

« Last post by Brent on May 17, 2021, 10:55:19 AM »

Hi Mike,

You bring up a good point. HyperSizer does not account for the reduced allowable when filtering cases based on peak element metrics.

One suggestion to check if you are missing any critical cases is to run an analysis with peak element and then another analysis with element based. Make sure you are not sizing to keep runtimes down to a minimum. Then compare the critical load cases from the element based run to see if any "Hot" conditions were flagged that were not flagged in the peak element run.

Hope this helps!

Brent

37

Analyzing & Optimizing Stiffened Panels / FEA Loads - Peak Element Filtered

« Last post by mjlafrenier on May 14, 2021, 03:08:52 PM »

All,

Does HyperSizer give any consideration to thermal loading when developing the peak elements when peak element filtered is selected (for large models/many load cases)?

The concern is that until final sizing is done for all elements (element based), then its possible that a cold day/room temperature case with a larger load could be hiding a more critical but lower load hot day case with a reduced allowable.

Thanks,
Mike

38

Scripting / How to create new component via VBA? No ComponentCol.Create method exists.

« Last post by Usr182x on April 19, 2021, 11:15:51 AM »

Is there method of creating a new component similar to how a new assembly can be created with AssemblyCol.Create()?  Neither classes (Component or ComponentCol) have a "New()" or ".Create" method.  Is there a trick to it or is it impossible to do via scripting?

I'm wanting to create components similar to the way you can use the FEM Viewer GUI by selecting menu items Component -> Create Using FEM Viewer (by element).  I would like to use Excel to create components by using [Component Name, Component ID, Element ID List].  The FEM Viewer allows a user to define a component with nothing but these three variables.

Thank you.

39

Analyzing & Optimizing Stiffened Panels / Re: HS Orthogrid Panel Smeared Stiffened Analysis

« Last post by James on March 22, 2021, 02:57:34 PM »

In that case, I'd recommend modeling them in and using HyperSizer + Nastran Sol15 to size for buckling.

-James

40

Analyzing & Optimizing Stiffened Panels / Re: HS Orthogrid Panel Smeared Stiffened Analysis

« Last post by mjlafrenier on March 22, 2021, 02:55:05 PM »

Thanks James,

The cutouts would be bound by stiffeners and integrated into the orthogrid, but would be larger and span at least several bays. The shape will likely be a large slotted shape or circular.

Best,
Mike