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stiffness v/s no. of elements

Submitted by vjuair on

hi,

   i am new to finite elements, i may be wrong, wnen i was solving a problem of hanging beam and load applied at its free end for obvious reasons there was a displacement at the free end. when i increased the no. of elements, deformation was minimum compared to previous result. does this actually mean stiffness got increased? as the basic thing about stiffness is that it depends only on geometry, material property and boundary conditions which were all constant in my case. alll i want to ask is, does stiffness depends on no. of elements? 

thanks

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SivaSrinivasKolukula

Hello

          FEM is numerical method. You know that, numerical methods are only approximations to the real actual solution. Every numerical method have some error, they deviate from the real solution. So is FEM. The error in FEM depends on the number of discretizations (no. of elements). The more the number of elements you take, the close the FEM solution to real solution. Accuracy of FEM solution can be improved by increasing number of elements. There exists a number of elements for which solution rmains same, even on increasing the number of elements. So, for every problem solving in FEM, a convergerncy of the solution must be studied.

         It is not that, the stiffness depends on the number of elements. Increasing the number of elements, solution is going close to real solution. Read first chapter of any FEM book, about FEM error will be discussed.

 

With regards

Sreenu 

Mon, 05/14/2012 - 03:42 Permalink