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Homework Help: Shape Functions Problem

  1. Mar 19, 2008 #1
    1. The problem statement, all variables and given/known data

    I am asked to determine two shape functions based off of a polynomial and Boundary conditions that are given at this url: http://i267.photobucket.com/albums/ii286/TechNewsSource/ShapeFunctions.jpg" [Broken]

    I would have posted it here but I can't remember how to do symbols on forums.

    3. The attempt at a solution

    Anyways, using the prescribed boundary conditions, which are the result of a beam fixed at both ends, I couldn't determine what to use for the two shape functions. I know that using x/L and (x/L)^2 would be valid shape functions, but I am not sure how to determine the shape functions based off of the given polynomial. I am sure it is something simple I am missing, but I just couldn't figure it out. Any help is greatly appreciated. Thanks
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Mar 19, 2008 #2
    Anyone have an idea?
  4. Mar 19, 2008 #3


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    try going to any number of posts that has math formulae in it, click "Quote" and see how they did it.

    the two [itex]\Psi[/itex] equations have nothing differentiating them from each other. the second one tells you nothing that the first one doesn't already tell you, which is not enough. you have 4 parameters to determine and only 2 constraints.

    i would recommend that people refrain from helping until you make it easier for them to do so (by learning [itex]\LaTeX[/itex] and using it).
  5. Mar 19, 2008 #4
    The link shows all the information that was provided, so why are you telling people not to help because the information is not in the post? It is very easy to right click on the link and open in a new tab!

    Also, there is only one equation given, that is to be used to determine two shape functions. I am not sure if the unknowns (a,b,c and d) are to be used, but are in the eq. to show the definition of the polynomial.
  6. Mar 21, 2008 #5
    Nevermind, I figured it out myself. However, it doesn't look like I was going to get help anyways.
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