How to show bending stress of the shell element ?

Iskw
Iskw Altair Community Member
edited October 2020 in Community Q&A

As far as I understand, the mises stress at the middle of the shell element is membrene stress, and the mises stress at the surface of the shell element is sum of the membrene stress and bending stress.

and the hyperview can show the stress of the mid layer and both surface layer of the elements.(Z1, Z2, or Max)

How can I show the contour plot of only the bending stress of the element ?

 

I mean that I want to get the contour plot of value of ((Z1, Z2 or Max) - Mid layer ).

 

Thanks for your help in advance.

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Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2018

    By default OptiStruct solver extract results for stresses at element centroid. At preprocessing stage we have option to get stress output at corner.In that case one can envoke use corner data option in HyperView.

    In HyperView you would get option to get stress at different layer for shell element. PFA screenshot for your reference.

    <?xml version="1.0" encoding="UTF-8"?>Layer in HV.JPG

  • Iskw
    Iskw Altair Community Member
    edited February 2018

    Sorry for confusion.

     

    Please find attached picture.

    In this picture, the (1) shows the mises stress at the middle of the thickness of shell element.

    (2) shows the mises stress at the each surface of the shell element. in other words, the mises stress value of Z1 and Z2.

    The stress value of (2) is consists of (membrane + bending) stress, so I thought that I can extract the bending stress (3) from (2) - (1).

     

    As for an individual element, I can obtain the (3) value by hand calculation, but I want to get the contour plot of the (3) = (2) - (1) at whole model.

    Or is there any direct method to plot the contour of the bending stress ?

     

    <?xml version="1.0" encoding="UTF-8"?>5a8d23ab8d474_stressshellelem.thumb.png.35f0d936b36086f362124bc2afac7c8b.png

     

  • tinh
    tinh Altair Community Member
    edited February 2018

    Did you try using Results>Create>Derived Results?

  • Mario_21478
    Mario_21478 Altair Community Member
    edited February 2018

    Hello,

     

    Do it as tinh has proposed.

    Be sure to load your files with Result-Math template 'Advanced'.

    Then call the Expression Builder (Derived Results) and create a Tensor for bending. See attached picture.

     

    Best Regards,

    Mario

     

     

    <?xml version="1.0" encoding="UTF-8"?>BendingStress.PNG

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited February 2018

    As @Rahul R : Different stress in shell found in different layers:

    shell_stress.png.0288b2cd6fadbc2784bbcbdca0f197ea.png

     

    • Middle layer => Membrane stress
    • Lower/Upper layers => Membrane + Bending stress
  • Iskw
    Iskw Altair Community Member
    edited February 2018

    Thanks all !

    What I want has been achieved by creating the result of { Z1(or Z2) - Mid } layer's von mises stress in 'derived results'

  • Shivani Tiwari
    Shivani Tiwari Altair Community Member
    edited January 2019

    By default OptiStruct solver extract results for stresses at element centroid. At preprocessing stage we have option to get stress output at corner.In that case one can envoke use corner data option in HyperView.

    In HyperView you would get option to get stress at different layer for shell element. PFA screenshot for your reference.

    <?xml version="1.0" encoding="UTF-8"?>Layer in HV.JPG

    Sir can you please tell if I have a set of elements for Static load analysis and want to calculate von misses stress.

    Which layer should I use? 

    As I am new to it I don know 

     

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited January 2019

    Max Von Mises stress found always on upper or lower layer. If you shell has small thickness and loading is not so important, the difference between layers is small.

  • Shivani Tiwari
    Shivani Tiwari Altair Community Member
    edited January 2019

    Max Von Mises stress found always on upper or lower layer. If you shell has small thickness and loading is not so important, the difference between layers is small.

    Means upto 2 mm thickness I can use value of any of layer?

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited January 2019

    How about dimension of your structure? BC? Loading?

  • Shivani Tiwari
    Shivani Tiwari Altair Community Member
    edited January 2019

    How about dimension of your structure? BC? Loading?

    Sir it is a sheet metal component i.e., Exhaust System

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited January 2019

    Hyperview can show you max value of von Mises stress over all layers, for each element.