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SPRstructur15-Moonstone
15-Moonstone
February 3, 2022
Solved

11.9.2 Transformation of the nodal coordinates of the space frame element

Dear All 
Please help for calculating  Transformation of the nodal coordinates of the space
frame element, I stuck here both theory and Mathcad Prime.

I attached file of Mathcad prime sheet and lesson and example.

Best regards
SPRStructur

 

terryhendicottAnswer
21-Topaz II
February 4, 2022

Hi,

Have eliminated the error.

The case where the member aligns with the z axis needs to be taken into account.

Have added an if statement that defines this.

Cheers

Terry

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39 replies

terryhendicott21-Topaz II
21-Topaz II
February 4, 2022

Hi,

Here is how a commercial piece of software defines P on the y(2) axis.

In the graphic axis 3,2,1 is the same as your local coordinates x,y,z.

x(3) local is along the member.

y(2) local is defined as Y global for beams parallel to Z global axis.

y(2) is defined by vector product of Z and 3 if not parallel to Z global

z(1) completes the orthogonal set.

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Define y(2) as above and you can set P for your example.

 

Cheers

Terry

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    terryhendicott21-Topaz II
    21-Topaz II
    February 4, 2022

    Hi,

    Took time to show how to calculate P.

    The case for element on z axis is trivial so not covered.

    Cheers

    Terry

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      SPRstructur15-MoonstoneAuthor
      15-Moonstone
      February 4, 2022

      Hello @terryhendicott 
      I got error when I apply my example

       

       

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      terryhendicott21-Topaz IIAnswer
      21-Topaz II
      February 4, 2022

      Hi,

      Have eliminated the error.

      The case where the member aligns with the z axis needs to be taken into account.

      Have added an if statement that defines this.

      Cheers

      Terry

      Capture.JPG

      Translate
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