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PreVabs problem: web creation

  1. Qi Wang

    Hi,

    I downloaded the recently released new prevabs and want to create an simple ellipse cross-section with web. 

    In the manual, it states that "Level of a Segment is used for dealing with structures with "T" shape connections, such as the web in an airfoil cross section". I am trying to use "level" to create the web. However, if I set level="10", like those in the mh104 example, an error message was pop-up:

    -----------------------------------------------------------------------------------------------------------

    C:Projectprevabs-v0.5>prevabs -i SSVM/ssvm.xml -v
    PreVABS Version 0.5
    >>>>>>>>>>>>>>>> Open file: SSVM/ssvm.xml
          0 [main] prevabs 10120 cygwin_exception::open_stackdumpfile: Dumping stack
     trace to PreVABS.exe.stackdump

    -----------------------------------------------------------------------------------------------------------

    Then I noticed that in the "level" note, one point is that "The first level number must be 1 always." However, the mh104 web "level" was set to "10" and there is no other "level" was given in the input. If I set my web level to 1, the web was created but not cut by the outer surface. One screenshot for this case was included in the uploaded folder.

    I uploaded all the files for this case and please help solve the problem.

    Thanks!

    Qi 

     

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    1. Qi Wang

      Hi Su, Thanks for your help! The bug was fixed by defining the baseline clockwise for "airfoil" type cross-section. I think this should be added to the manual. In addition, I did some test cases on the "airfoil". Some notes may be included into the manual like the "clockwise" rule. For example, I found that the "connection" is only valid when the "airfoil" type cross-section defined in the scaled format, i.e., the chord-wise coordinate ranges from 0 to 1. Moreover, the "z" frame needs to be placed at the leading edge otherwise an error message pop-up. Thank you very much for the help. Qi On Mon, Apr 16, 2018 at 1:59 PM, Su Tian @ cdmHUB - The Composites HUB < support@cdmhub.org> wrote: ---- Emailed forum response from aaron.qi.wang@gmail.com

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    2. Su Tian

      Hi Qi,

      For the current version (v0.5), there are some conventions and limitations.

      1. By default, the level of a segment is always 1. So if the keyword 'level' is omitted, then this segment has level 1. Then the level of the web should be assigned a number greater than 1 explicitly.
      2. For an airfoil type cross section, the order/arrangement of segments and the direction of baselines have to be clockwise. The direction of a baseline is specified as the order of the point list in the basepoint file. And the order of the segments is specified in the main input file. This also requires that the layup direction of segments should always to the right side of the baselines.

      I know that the second requirement is very inconvenient. This limitation will be removed in a future update.

      The modified files are attached. Materials and layups files are not touched.

      Su

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      Replying to Su Tian

    3. Su Tian

      Hi Qi,

      For the current version (v0.5), there are some conventions and limitations.

      1. By default, the level of a segment is always 1. So if the keyword 'level' is omitted, then this segment has level 1. Then the level of the web should be assigned a number greater than 1 explicitly.
      2. For an airfoil type cross section, the order/arrangement of segments and the direction of baselines have to be clockwise. The direction of a baseline is specified as the order of the point list in the basepoint file. And the order of the segments is specified in the main input file. This also requires that the layup direction of segments should always to the right side of the baselines.

      I know that the second requirement is very inconvenient. This limitation will be removed in a future update.

      The modified files are attached. Materials and layups files are not touched.

      Su

      Reply Report abuse

      Replying to Su Tian

    4. Su Tian

      Hi Qi,

      For the current version (v0.5), there are some conventions and limitations.

      1. By default, the level of a segment is always 1. So if the keyword 'level' is omitted, then this segment has level 1. Then the level of the web should be assigned a number greater than 1 explicitly.
      2. For an airfoil type cross section, the order/arrangement of segments and the direction of baselines have to be clockwise. The direction of a baseline is specified as the order of the point list in the basepoint file. And the order of the segments is specified in the main input file. This also requires that the layup direction of segments should always to the right side of the baselines.

      I know that the second requirement is very inconvenient. This limitation will be removed in a future update.

      Su

      Reply Report abuse

      Replying to Su Tian

    5. Su Tian

      Hi Qi,

      For the current version (v0.5), there are some conventions and limitations.

      • By default, the level of a segment is always 1. So if the keyword 'level' is omitted, then this segment has level 1. Then the level of the web should be assigned a number greater than 1 explicitly.
      • For an airfoil type cross section, the order/arrangement of segments and the direction of baselines have to be clockwise. The direction of a baseline is specified as the order of the point list in the basepoint file. And the order of the segments is specified in the main input file. This also requires that the layup direction of segments should always to the right side of the baselines.

      I know that the second requirement is very inconvenient. This limitation will be removed in a future update.

      Su

      Reply Report abuse

      Replying to Su Tian