Elastic guided waves are of interest for the non-destructive evaluation (NDE) of cables. Guided waves are multimodal and dispersive. Cables are complex structures, helical, multi-wired and highly prestressed. This further complicates the interpretation of measurement. Numerical models are required for understanding guided wave propagation and optimizing inspection systems. This paper reports on the modeling of wave propagation inside seven-wire strands, typically encountered in civil-engineering cables, including complicating effects such as geometry curvature and prestress. Special attention is given to the interwire energy transfer occurring in a seven-wire strand excited by a source localized in a single wire. Numerical results show how the energy transfer decreases with frequency, which leads to the discovery of a compressional mode of local type. This mode may have interesting features for the NDE of cables.