As composite laminates have become essential to numerous modern industries, Structural Health Monitoring (SHM) strategies have to be implemented in order to manage the aging of structures made out of composite materials. In this paper, we present and compare two approaches involving solid and plate Spectral Elements (SE) in the time domain, with respect to their ability of modeling composite delamination: a task which lies in the context of modelbased data processing for non destructive evaluation techniques with Guided Waves (GWs). To this end, we review the multilayer flat shell delamination model [1], and propose a singlelayer alternative by extending the Layered Solid Spectral Element (LSSE) [2] method by means of partition of unity enrichment functions [3].These approaches are then compared in a numerical example with different damage scenarios. Finally, conclusions on the benefits and drawbacks of these two strategies are presented.