Software Use > Miscellaneous Software Topics

Error while sizing Uniaxial components

(1/2) > >>

ULBsha:
Hi,

I'm sizing a structure containing different type of elements (beam and panels - Unstiffened, grid stiffened, uniaxial, ...) and for one load case, I get the following error on the uniaxial component:

An error occurred while executing a user-defined analysis:
"Stiffener buckling, flat, flexural-torsional stability, argyris"




In the *.HDG file, I get:

A local buckling length to width span ratio is less than 1.
Length A has conservatively been set equal to the larger B length for this optimisation attempt.

Could someone please help me ?


PS: if I toggle off the "Buckling, Stiffener" failure analysis mode of all the selected concepts, the component can be analysed without any error...


Thanks.
Regards

Ryan:
What version of HyperSizer are you running? Previous versions had issues with load cases with low -Nx and high +Ny load. What do the design-to loads look like for the problematic load case?

Could you post the HDG file as well?

Thanks,
Ryan

ULBsha:
I'm using V6.4.53.

I don't have a clear idea of the order of magnitude for 'low' and 'high' load values. Please find attached a screenshot of the Design-to load tabs for one case that works correctly (left) and the case with the issue (right).

I also attached the HDG file.

Thanks again

Ryan:
There was an issue in V6.4 for cases with compressive Nx and tensile Ny in ratios where the +Ny load stabilized the skin from buckling (buckling load = infinity). This caused an error with the flexural-torsional buckling routine because it requires a local buckling as an input. This has been addressed in V7.0, so there's a good chance this case will work in 7.0.

In your screenshot, the load case numbers for the left and right are the same. Also, the loads in the right hand side are pink which indicate that the data has not been updated - in order to the view the load case that it causing the issue, first you will have use process of elimination to figure out which load case is the problem (deactivate half the load cases, rerun, if the error occurs, deactivate half of the active load cases, and repeat). Once you have the load case figured out, you can deactivate FTB, rerun, and look at the design-to loads to have a look at the load state that is causing the issue.

-Ryan

ULBsha:
Dear Ryan,


--- Quote from: Ryan on July 08, 2014, 11:48:41 AM ---In your screenshot, the load case numbers for the left and right are the same.

--- End quote ---

Actually they are not the same. The mechanical load cases (500) are the same, however, the thermal loads are different, even if the ID is the same (501). In the right hand side (the analysis that doesn't work), the structure is applied to an ambient temperature of 295K. But since the initial temperature is also 295, I guess that we can assume there is no thermal load since we will not have any thermal stress and the material properties are still not degraded. On the other hand (the left hand side analysis that works fine), a 800K thermal load is applied to the structure, and as I said, this one works without any problem.




--- Quote from: Ryan on July 08, 2014, 11:48:41 AM ---Also, the loads in the right hand side are pink which indicate that the data has not been updated -

--- End quote ---

But isn't this because the analysis can not be performed ? Even if I refresh the window, it remains pink..



--- Quote from: Ryan on July 08, 2014, 11:48:41 AM ---in order to the view the load case that it causing the issue, first you will have use process of elimination to figure out which load case is the problem (deactivate half the load cases, rerun, if the error occurs, deactivate half of the active load cases, and repeat). Once you have the load case figured out, you can deactivate FTB, rerun, and look at the design-to loads to have a look at the load state that is causing the issue.

--- End quote ---

If, with the same load cases, I turn off FTB of all the selected concepts, there is no more issue as I said previously. Please find attached the Design-to load tab. They do not look too high/low to me...


PS: And what about the HDG file ?


Thanks

Navigation

[0] Message Index

[#] Next page