The dynamical behaviour of systems in medium and high frequency range has become a subject of increasing interest over the last few years. Recently, an original strategy called Energy Flow Method has been developed to describe the structural/acoustical response in mid frequencies. In this paper, a review of the one dimensional Energy Flow Method is first proposed. An original propagative method based on the reflection and transmission matrix is proposed to study coupled beams with longitudinal and transversal motion. The method is applied to the junction of two beams with an arbitrary angle. The results show the efficiency of such a formulation for the mid frequency analysis of beam networks.