Regarding reaction of the symmetric frame when subjected to floor load

The given frame is symmetric in loading, member properties and arrangement (Model is attached). Member offsets are defined in beams.

Since structure is symmetric, all support reactions should be same in all symmetrical loading conditions.

And the same is observed for UDL and concentrated loads on beams.

But if floor load is applied, then support reactions are not equal.

Why is it so ?

Note: This is observed when I defined member offsets for beams.

Test_Model.STD

  • Hello,

    Your observation and expectation is right. We will investigate and find out the reason. But, with a quick look I found a fix. As you mentioned this is happening for beams with offset I tried a few things and found that if we change the START and END of the members 6 and 7, then the values are as expected.

    The file you shared is having below member incidences. Green is START and blue is END. Here, you will find different reactions.

    Now I have changes the beam incidence and you will find same reactiuon as shown below.

    Please try at your end and let me know.

    I will investigate more and try to find the reason. If there is a bug, we will fix this.

    Thanks & Regards,
    Abhisek Mandal
    Global Technical Support