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    Autodesk Robot Structural Analysis

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    Valued Contributor
    Posts: 78
    Registered: ‎08-02-2012
    Accepted Solution

    deflection of cantilever stairs

    303 Views, 5 Replies
    08-02-2012 06:34 AM

    Afternoon,

    I'm trying to model some basic stair slabs which are cantilevered off 2 RC walls. The vertical end deflection of the upper platform doesnt seem to be showing in the results. Have I missed something? I've attached the RTD file in zipped format.

    Many thanks in advance for any helpful feedback! :smileyhappy:

    Scott

     

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    Product Support
    Artur.Kosakowski
    Posts: 2,773
    Registered: ‎12-17-2010

    Re: deflection of cantilever stairs

    08-02-2012 07:07 AM in reply to: Opel5

    Scott,

     

    The definitions of loads in cases 2 and 3 are incorrect - you don't have results for these cases therefore you have no results for combination 4 too.

     

    incorrect load definition.PNG

     

    I have tried to correct these loads but check if the values are right (corrected model attached).

     

    If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.



    Artur Kosakowski
    Support Specialist
    Product Support
    Autodesk, Inc.

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    Valued Contributor
    Posts: 78
    Registered: ‎08-02-2012

    Re: deflection of cantilever stairs

    08-02-2012 07:39 AM in reply to: Artur.Kosakowski

    Many thanks for the speedy reply Artur! Excellent, nice to see it working.

     

    The practical allocations of FE planar loading seems a bit confusing, as there seems to be multiple ways of allocating the loads to the panels. In this instance I added planar loads to each panel in turn which caused the error. Is there a particular PDF resource that you'd recommend which explains the allocation sequence fairly clearly?

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    Valued Contributor
    Posts: 78
    Registered: ‎08-02-2012

    Re: deflection of cantilever stairs

    08-02-2012 07:51 AM in reply to: Opel5

    Argh, sorry back again!


    On switching the uniform load back to a planar load (to simulate the area loading from a concrete screed / tiles / grout etc) the same error occurs. I've attached a screenshot and the RTD file.

     

    If anyone knows how to deal with this error where connecting panel edges meet please let me know.

    Many Thanks,

    Scott

     

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    Product Support
    Artur.Kosakowski
    Posts: 2,773
    Registered: ‎12-17-2010

    Re: deflection of cantilever stairs

    08-02-2012 07:57 AM in reply to: Opel5

    What is the way you define the planar load? If you use the 3 point definition (variable surface load) make sure the A,B.C points are not the same and are not defined along a line.

     

    If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

     

     



    Artur Kosakowski
    Support Specialist
    Product Support
    Autodesk, Inc.

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    Valued Contributor
    Posts: 78
    Registered: ‎08-02-2012

    Re: deflection of cantilever stairs

    08-02-2012 08:13 AM in reply to: Artur.Kosakowski

    Hi There,

    I've managed to solve the problem by specifying "surface on object" planar loads rather than "FE planar loads". It's working well now without the calculation error messages at FE panel edges coming up. Thanks for the speedy feedback

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