Linear Strain Triangle (T6)

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Linear Strain Triangle (T6)

 

This element is also called quadratic triangular element.

There are six nodes on this element: three corner nodes and three mid-side nodes (Fig.20). Each node has two degrees of  freedom (DOF). The displacements (u, v) are assumed to be quadratic functions of (x , y).

 

 

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Fig.20. Quadratic triangular element.

 

 


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(43)

 

                                 

From these, the strains are linear functions, thus we have the "linear strain triangle" (LST), which provides better results than the CST.

 

In the natural coordinate system, defined earlier, the six shape functions for the LST element are:

 


p_27_image006

 

 

 

(44)

 

                                                             

in which p_27_image008.

 

Displacements can be written as:

 


p_27_image010

 

 

 

(45)

                                                     

The element stiffness matrix is still given by:

 


p_27_image012

(46)

                                                           

but here BTEB is quadratic in x and y. The integral is computed numerically.

 

 

 

 

 

 

 

 


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