The matrix of the transforming of vibration waves

Scattering of the linear vibration waves on a nodal junction of elastic plates is considered. For description of transforming (transmission, reflection, refraction and transformation into other types) of such waves we use the transformation matrix. We have proved for this matrix some usual properties related with the reciprocity principle and with conservation of energy. In the case when a source of field is evanescent wave we have found a new property of the generalized scattering matrix. This property reflects the conservation of energy at such process.