Max Section Displacement

Continuation to my previous query, here are the two identical beams, one with node at mid point and another one is without any node at mid point. refer the snap below for Max section displacement. In the report, beam with node showing lesser displacement(1.869) than the actual displacement (9.712) . I would like to understand why this difference is coming ?  and how to solve this issue. Staad file is also attached.

DFF.STD

  • Hello Magesh,

    The section displacement table always report the maximum local deflection for each analytical member. So, if you double click on the member and check the local displacement in Y direction, the values you are seeing in your snap will match.

    You can refer help file to know how the deflection values are calculated.

    Please refer notes in the below page.

    Home > Design > D. Design Codes > D3. British Codes > D3.B. British Codes - Steel Design per BS5950:2000 > D3.B.6 Design Parameters

    For your case, you can match the value with manual calculation also. Here, the length of beam number 2 is 2.5m. The maximum global deflection at node 3 is 9.712mm. The global deflection at a distance 1.458m is 7.534mm.

    Now, you can draw the beam and draw a point to indicate 9.712mm displacement. Then, add a beam to connect the end two nodes of the displaced shape. After that, you can measure the difference of global displacement and displaced shape at any point to get local deflection.

    However, if you check the output file (.anl file) you will fidn the result for both teh cases are same and global displacement as per your input has been considered.

    Thanks & Regards,
    Abhisek Mandal
    Global Technical Support

  • Hi Abhisek, 

    Your explanation helped me to understand the various values we get in section displacement table. whereas I am looking for section displacement value (Which is used to calculate deflection checks ) in report form for the beams with node at any location in the length of the beam. In output file I could not find the displacement value of 9.712 for beam 2 and 3.