A convenient health monitoring technique for detecting degradation in laminated composite is to monitor the change of electrical resistance along multiple conduction paths. Yet, the relations between the global modification of resistivity and the exact underlying damage map is still unclear that makes difficult to interpret these non-destructive-testing results. The challenge is then to be able to reconstruct from these global observation the underlying damage map. This paper intends to provide some preliminary insights about strategies to recover the damage state based only on global measurements. We focus here on transverse cracking detection. We introduce the homogenization process that defines at the meso scale an equivalent homogeneous ply that is energetically equivalent to the cracked one. © 2014 Lavoisier.