Issue 50

O. Mouhat et alii, Frattura ed Integrità Strutturale, 50 (2019) 126-140; DOI: 10.3221/IGF-ESIS.50.12 129 1 1 1 1 1 1 , , , , N N N i i i i i i i i i N N N x i x i y i yi z i z i i i i u N u v N v w N w N N N                         (2) Figure 1 : Panel cross-section Figure 2 : Coordinate System with the displacement Where i N is the global number of nodes, the Lagrangian method is used in this work for each node, we define the response vector i q as:         i i i T i i i i x y z q u v w (3) The total deformation is written in the following form:       0 1      2 2 , , ,x 2 2 ,y ,y ,y ,y ,x , , , y,y ,y y,x , ,x 2 0 1 0 2 0 0 0 0                                                                               x x x y x x x y y x z u v w v u w u v w w w w     (4) where     T x y xy x y xy yz zx z            (5)