Getting Twist Angle on Shaft Under Torsion

Achmad Zufar
Achmad Zufar New Altair Community Member
edited March 2021 in Community Q&A

Hi Everyone, 

 

I'm running a simulation where the model is a shaft under pure torsion loading. My goal is just to validate the result of my FEA and see if it matches my calculation. I'm using a tetramesh model and even thoughthe meshing is coarse I kind of get similar value to my hand calculation on the shear stress part. 

 

The problem comes when I tried to generate the twist angle of the shaft, for some reason the value for that is really small compared to my calculation. Does anyone experience this? What do I need to do to fix this?

Attached is the file that I'm using. 

Best,

 

Ariq

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Answers

  • Rogerio Nakano_21179
    Rogerio Nakano_21179 New Altair Community Member
    edited March 2021

    Hi

    Based on the geometry (D=3.84, and length=18)

    , the material (Poison=0.3 and Young Modulus = 1,060,000)

    and load (torque = 1,000) the value of angle is estimated as:

     

    Angle  is about 0.002rad

     

     

    Is this the estimated value you are getting?

     

    Regards

     

  • Achmad Zufar
    Achmad Zufar New Altair Community Member
    edited March 2021
    Rogerio Nakano_21179 said:

    Hi

    Based on the geometry (D=3.84, and length=18)

    , the material (Poison=0.3 and Young Modulus = 1,060,000)

    and load (torque = 1,000) the value of angle is estimated as:

     

    Angle  is about 0.002rad

     

     

    Is this the estimated value you are getting?

     

    Regards

     

    Yes. Unfortunately in my model it did not generate any twist angle. It says 0 for it. Do you know what might have happened?

  • Rogerio Nakano_21179
    Rogerio Nakano_21179 New Altair Community Member
    edited March 2021
    Achmad Zufar said:

    Yes. Unfortunately in my model it did not generate any twist angle. It says 0 for it. Do you know what might have happened?

    Hi

     

     

    if you need the angle of shaft twist , what you could do is

    - in HyperView create a local cylindrical coordinate system that is centered in the face that you are applying torque, with the z-axis aligned to the shaft axis.

    - So that x -> radial disp (r) and y-> angular disp (theta)

     

    - when contouring, you select the displacement result, y-component. Also select the user defined coordinate system and contour.

     

    image

    - That will contour the angular displacement of the nodes relative to the local cylindrical coordinate system

    - you can query the external diameter nodes and check the rotation of this nodes, relative to the origin of local coordinate system, that is the center of rotation you selected.

     

    I hope that is helpful

    Regards

     

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