Recent Posts

61

HyperSizer Stress Reports / Overall Summary-Controlling Failure Mode, Negative Margin Structure(kg)

« Last post by cmcho on January 04, 2021, 01:00:29 AM »

In "Overall Summary" of stress reports, what do you mean by "Controlling Failure Mode, Negative Margin Structure(kg)?
I have some value in this weight description in stress reports, although there was no negative margin component after detail sizing. What I can not understand is every component would be sized by satisfying one of failure modes at minimum margin of safety. Could you explain what it is and when this can happen?

Thanks.
Changmin

62

Creating & Editing Composite Laminates / Re: Bending-twisting coupling in effective laminates

« Last post by James on December 21, 2020, 11:59:50 AM »

The ABD shown in the help topic is for a discrete laminate with the same ply percentages. This is not the effective laminate ABD. You're correct that the D16 and D26 bending coupling terms are ignored for effective laminate sizing.

-James

63

Creating & Editing Composite Laminates / Bending-twisting coupling in effective laminates

« Last post by mraedel on December 20, 2020, 11:31:39 AM »

This question is related to the picture in the "In-Plane" section of http://hypersizer.com/help_7.3/#Materials/EffLam/el-properties-stiffness.php.

From my understanding you get bending-twisting coupling, so populated D16 & D26 terms, in the laminate stiffness matrix and therefore non-orthotropic stiffness behavior in bending as soon as you have non 0° or 90° layers in your discrete stacking sequence, e.g. by +45° and -45° layers. The reason is that, even if the stacking sequence is symmetric and balanced, +45° and -45° layers may not be located at the same offset from the middle-plane.

However, this information, the stacking order and therefore distance from the laminae middle-plane to the stacking sequence middle plane gets lost in the effective laminate approach. The approach for the calculation of the bending stiffness is described here: http://hypersizer.com/forum/index.php/topic,535.0.html

So how can it be that the ABD-matrix shown in the mentioned figure has D16 & D26 populated?

64

FEM Coupling (HyperFEA) / Re: Temperature Dependent Material Properties in HyperFEA

« Last post by bacjac on December 09, 2020, 10:41:05 AM »

OK James, thanks for the explanatory material I have finally got things sorted out right on my end and see everything working correctly.   Whew - sorry for the inconvenience. pdf attached shows the case checks that seem to be working correctly now.

65

Analyzing & Optimizing Composite Layups / Re: Load Set Factors vs Component Load Factors

« Last post by Stephen on December 04, 2020, 08:41:08 AM »

Hi Dana,

Yes, the component-based load factors are multiplicative with the load set load factors. So a 1.5 ultimate factor on a load set, combined with a 1.5 ultimate factor on a specific component, will result in a total of 2.25 ultimate factor for this component.

In general we recommend not using the component-based load factors unless there is a specific circumstance that would require you to assess different factors on a given component.

-Stephen

66

Analyzing & Optimizing Composite Layups / Load Set Factors vs Component Load Factors

« Last post by dana.frye on December 04, 2020, 03:17:33 AM »

I am working on a FEA project, and the model I input had load cases defined in limit load space. On the 'load sets tab' of the project setup form, I have a ultimate factor of 1.5 defined. If I also add a 1.5 mechanical ultimate factor to the 'FEA Loads' tab of the project sizing form, would that be effectively double-dipping on the 1.5 FoS?

67

Scripting / Obtaining the Fatigue Kt Skin and Stiffener for Beam concepts

« Last post by Gawain on December 02, 2020, 11:51:22 AM »

Hi

I'm trying to extract the Fatigue Kt Skin and Stiffener values for a Beam concept.  I can write a python script to extract these values out for a panel concept but there's nothing within the BeamProperty class for extracting these values for a Beam concept.

I want to apply a kt to a Web beam concept and be able to control the Kt value during each HyperFEA loop using a python script (Kt will changed based on the height of the Web Beam), is there a way of doing this?  Currently using version 8.0.54.

Regards

Gawain

68

Miscellaneous Software Topics / Re: Analysis time increased with 7.3.37 installation

« Last post by James on October 28, 2020, 01:53:14 PM »

Are you using filtered load cases?
http://hypersizer.com/help_7.3/#BackdoorData/bd-17-load_case_filtering.php

Peak element vs. element-based vs. statistical load processing methods?
http://hypersizer.com/help_7.3/#Loads/load-fea.php%3FTocPath%3DFeatures%7CFEM%2520Interface%7CFEA%2520Loads%7C_____1

-James

69

Miscellaneous Software Topics / Re: Analysis time increased with 7.3.37 installation

« Last post by ruth.k.ross@spiritaero.com on October 28, 2020, 10:49:57 AM »

I'm having a rather similar issue to what was originally described.
I have
1 project
2 assemblies
658 components
57 effective laminates.

It was taking 2 hours to run last week, but it suddenly went to about 24 hours to run only 1 of the assemblies.

Any idea why this would've suddenly changed, and how to reduce run-time?

It looks like the exhaustive search flag has already been set as a default to "no".

70

Scripting / Re: Getting joint data using vba

« Last post by Stephen on September 25, 2020, 10:07:31 AM »

Hello,

Unfortunately, no it is not currently possible to extract joint-related data through the VBA scripting API.

Thanks,
Stephen