Issue 41

M.F. Funari et alii, Frattura ed Integrità Strutturale, 41 (2017) 524-535; DOI: 10.3221/IGF-ESIS.41.63 526 0 T U W       (1) where T  is the virtual work of the inertial forces, U  is the work of the internal forces and the tractions across the interfaces and W  is the work of the external forces. According to the first-order transverse shear deformable laminate theory and multilayered approach, the variational form of the governing equations can be expressed by means of the following expressions:       1 2 0 1 0 1 1 1 0 0 1 1 0 0 1 2 l l i l l LN l l l l l l l l L L N N i i l l l l l l l i L L N N l l l l l l l l T U U dx, U N T M dx T dX , W f U h dX p U dx U U                                                           (2) where the subscripts l=1,..,N and i=1,..,N-1 indicate the numbering of the layers ( N ) and the interfaces ( N-1 ),   , ,    with   1 1 2 ' ' ' ,x U , U ,          represent the generalized strains,   N,T ,M are the generalized stresses defined as a function of the classical extensional   A , bending   D , bending–extensional coupling   D and the shear stiffness   H variables,   i t n T T T   is the cohesive interfaces traction vector ,   i t n      is the cohesive interface displacement jump vector,  and 0  are the mass and polar mass per unit length of the layer and l f  and l p  ,with   1 2 0 l f f f   and   1 2 l p p p m   , are the per unit volume and area forces acting on the l -th layer, respectively. Figure 1 : Layered structure: geometry, interfaces and TSL