Learning Forum

[Rameez_ul_Haq]

,I have just taken the basic finite element theory course, and therefore I am not aware of the indepth assembling of the stiffness matrix for a large global model. I guess I definitely need to read and research more about this, or take any advanced finite element courses to illuminate my mind on how does the complicated finite element works.nHowever, I just have a simple, naive question and I would be glad if you could clarify it here. I mean when the displacements are interpolated from the guass/integration points to the rest of the element, this would mean that a node connected to 8 hex elements would have 8 different displacements coming from each element it is a part of. Is this true? If it is, then does it mean that the nodal displacements that we see in our FEA results are basically also averaged out ones?nBut what I think is that the shape function behaves and works in such a manner that when it tries to interpolate the displacements back onto the nodes, it has to give the value of the displacement that was calculated by solving the simultaneous equations within the stiffness matrix. This means that even if a node is connected to 8 hex elements, all the shape functions of all the elements must eventually give the same displacement value at that node which is found by solving the global stiffness matrix. If this is how FEA works, then why can't we have the same thing happening for the strains and stresses as well for a node which a part of many elements?n