Mismatch in the reported values of Tension & Compression for vertical members

Hi,

With reference to the attached model, due to the symmetry about both axes, the reported Tension & Compression values in the modelled vertical members is being reported out of order for the orthogonal load cases 9.EQX & 10.EQZ.
Request to look at the file and let us know the correction required for mismatch in the reported values.

Sample_Pile_Check.STD

  • Hello Aakash,

    For load case 9 or 10 apart from the lateral load and moment there is some vertical load acting. Now, this vertical load will be added to the tension or compression force arising from the lateral load  and moment in the members. This vertical load will increase the axial force in compression case and decrease the value of tension case as the load is acting downward.

    If you delete the vertical load the axial force should match.

    Thanks & Regards,
    Abhisek Mandal
    Global Technical Support

  • Hi,

    Thanks for the quick reply!

    The values are exactly same in both the cases, so the results should be identical about both the axes!

    Our concern is that the results are not being reported same in spite of the symmetry of the structure.

    Regards,

    Aakash

  • Hello Aakash,

    I don't think so. Let me explain with an example. 

    The tension and compression in the legs will be due the couple or moment acting at the top. So, total moment divide by the lever arm will give tension in a side and compression in the other. Considering symmetry of the structure, the values will be same.

    Say, tension is -100 kN and compression is acting +100kN in this case.

    Now, there is a load acting vertically (FY value) downward. Which will create compression in the legs of equal magintude. So, due to this vertical load, say, each leg will experience 50kN compression.

    Now the effective axial force will be -100 + 50 = -50kN tension in legs in one side.

    On the other side the axial force will be +100 +50 = +150kN compression.

    Hope this clarifies your doubt.

    As a check you can make the vertical load 0 and check.

    Thanks & Regards,
    Abhisek Mandal
    Global Technical Support