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Hello everyone

I want to run a transient analysis for my model but there is a crash in my simulation. I was wondering if you knew how to manage the following errors.

*** ERROR # 1461 ***
 Card "LOAD" is not allowed for this subcase type.
 
 *** ERROR # 1461 ***
 Card "preptran" is not allowed for this subcase type.

 

Output file is in attachment.

Thank you.

file.out

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Hi @Question

 

Not sure where the load card is coming from. 

 

Can you please check the loadstep and see if there is any LOAD referenced? 

 

If you still face the problem, please share the model file.  

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Hello everyone

Is there any tutorial for fatigue analysis with S-N (stress-life) method for a cylinder under internal cyclic pressure, please? I am trying to set up the model by using tutorial "OS-T: 1340 Fatigue (Stress - Life) Method" in HM but some parts are not clear, as follows.

1. In table under loadcollectors, how to scale the internal cyclic pressure which is between 10 MPa and 60 MPa to have the same table in tutorial that is between -1 and 1?

2. How many cycles do I need to have in my model? In tutorial, there are 2545 cycles.

3. Which scale do I need to consider in FATLOAD? In tutorial, it is 3.

4. The cylinder is closed in its both ends, does it cause to have non-uniaxial stress? According to tutorial, S-N theory deals with uniaxial stress.

5. How to define "sets" in the cylinder model? In tutorial, there are 8 sets as eles11, eles22, ..., eles88.

Thank you.

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Hello everyone

Could you please let me know how to run the following tutorial in "Learn Fatigue Analysis with Altair OptiStruct" page 87?

4.4 Tutorial: Multiaxial Fatigue Analysis of a Knuckle

I set up the model but in results, there is no fatigue contour, as shown in figure of the previous post above. Fem file of my model is in attachment above.

Thank you.

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Hello Premanand Suryavanshi

How can a pressurized cylinder be simulated for a multiaxial fatigue analysis, please? Since it needs to be done in the Cylindrical coordinate system, how can the model be set up?

Thank you.

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Hello

In tutorial "OS-4050: Optimization of a Horizontal Tail Plane", in step 6, number 2, "Press the letter o on the keyboard (for the Options panel)." does not work. Could you please explain how to manage this problem to open Options panel?

Thank you. 

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Hi,

 

the Options panel can also be accessed with Preferences>Meshing Options.

 

The "o" keyboard shortcut should work- have you changed the hotkeys?

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Hi

Thank you for your reply. After running OptiStruct for tutorial "OS-4050: Optimization of a Horizontal Tail Plane", there is the following error. Please let me know how to manage it. Thank you.

A fatal error has been detected during input processing:
  *** ERROR # 1999 *** in the input data:
  In SUBCASE 3: card STATSUB references wrong type SUBCASE 2.

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The problem was that linear buckling loadstep (ID 3) was referencing a linear buckling loadstep (ID 2), which is invalid because STATSUB(BUCKLING) can only reference a static subcase.

Basically the loadstep ID 3 (buck_buck_pressure_only) is the same as ID 2, therefore is redundant and should be deleted.

I also suggest you rename load collectors and loadsteps as they share names and it is easily confused.

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Hi

Could you please look at the following von Mises stress contour and let me know if it is correct? It is for tutorial "OS-4050: Optimization of a Horizontal Tail Plane". In the rib sections, there are some discontinuties in contour. Thank you.

image.png.dfee7ba3ce6db5aa94ff1be186123edc.png

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