Hypermesh Post-Processing

Staedtlerp

Hi to everyone,

i performed a linear static analisys of square section thin walled beam and I encountered an unusual stress results. I used a Pbeaml property to have in output  Normal, Shear and VonMises stress. Concerning my section I have a max stress on point 4, so my Normal S4N value is 69.14 MPa. Then when I select Normal SNMax the value is the same. Otherwise there is a weirdness when I select Shear value, infact I have a maximum shear value at point 11 and its value is -25.33 MPa, but when I select Shear SSMax I obtain a positive value of 22.69 MPa. This occours displaying VonMises stresses, but less clear. /emoticons/default_blink.png' title=':blink:' />What does it means? Why This??? Thank You very much./emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />

Altair Forum User

Hi Staedtlerp,

 

Can you contour S1N, S2N, S3N results and check if they are less that S4N?

 

If they are less than S4N, then SNMax will be S4N. 

 

In order to check the Shear results, can you share the result file?

Staedtlerp

Hi Prakash,

thank you for your reply. I checked the SN and SS results. For the Sn results there aren't any problems, S4N was tha max and SNMax was the same. There is a problem concerning shear stresses value. S11S shear value is -25.33 MPa and it is the max, but Shear SSMax is positive and its value is 22.69 MPa.

Attached you can find results files. Thank you very much Prakash./emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />

Unable to find an attachment - read this blog

Altair Forum User

Hi,

 

Thanks for sharing the files. I will get back to you soon.

Altair Forum User

Hi Staedtlerp

 

Is it possible to share the model file?

Staedtlerp

Hi Prakash,

sure, here attached you can find the model file .hm. Thank you very much /emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />/emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />

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Altair Forum User

Hi,

 

I think the outer beam is in tension and the inner beam is compression. The Max tension is 22.69 and Max compression is ~25 (-25 as shown in legend).

 

When you contour the for  maximum I think only the Max tension stress is seen and not the compressive stress.

 

I will check with developers about this and will get back to you. 

Staedtlerp

Hi Prakash,

thank you for the reply and the patience. Yes the beam has a square section and accordingly with geometry, loads and constraints it is subjected to tension and compression stresses depending on the bending moment. But, always accordingly to geometry, loads and boundary conditions, it is subjected to a twisting moment and a shear stress. The twisting moment is the result of a shear stresses not passing through shear center. The problems is that, for this section (square type), in one side shear stresses add to torsion stresses and in the other side they substract. The value of -25.33 MPa is on side where torsion stress is added to shear stress (negative respect to Coordinate system). This value is logically the maximum shear stress because on the other side stresses substract, but when I check for SSMax a value of 22.69 MPa is displayed ( positive and smaller). I don't know why, i repeated many times the analysis but always the same results/emoticons/default_sad.png' srcset='/emoticons/sad@2x.png 2x' title=':(' width='20' />/emoticons/default_sad.png' srcset='/emoticons/sad@2x.png 2x' title=':(' width='20' />/emoticons/default_sad.png' srcset='/emoticons/sad@2x.png 2x' title=':(' width='20' />. I don't know where a get wrong/emoticons/default_sad.png' srcset='/emoticons/sad@2x.png 2x' title=':(' width='20' />!!!!!

Altair Forum User

Hi,

 

I will get back to you with more information soon