Among the methods for mitigating blast-induced damage to protected structures (PSs) is the installation of sacrificial claddings on structures under threat. Various materials can be used for these claddings, including Aluminum Foams (AFs). AFs, known for their energy-absorbing properties, effectively reduce peak overpressure from blast loads. Existing research has primarily focused on foams with uniform density, neglecting the coupled dynamic response between the PS and cladding. Moreover, structures that experience plasticity were seldom considered. Previous studies evaluated AF efficiency by comparing structural responses with and without AF. This method inadequately addresses the foam as an active energy absorber, as the AF contributes additional mass to the dynamic system that influences structural deformations, even in a fully compacted state. Furthermore, available research is often limited to specific blast loads, hindering a comprehensive understanding of AF assessments across a broader load spectrum. In this study, a numerical model for predicting the dynamic response of a non-uniform foam PS was developed by employing the shock front theory. The model was utilized to generate pressure-impulse diagrams and better understand the response of the coupled system to blast loads, obtaining unprecedented results regarding the AF effect on the PS.