## 1 Introduction  
Landmines continue to pose significant threats to both military personnel and civilians. According to casualty statistics from military conflicts, approximately 60% of injuries are attributable to the explosion of mines and improvised explosive devices (IEDs) [1]. The International Campaign to Ban Landmines (ICBL) reported that in 2022, the total number of casualties and specifically anti-vehicle mines resulting from explosive remnants of war reached 4710 and 102, respectively [2]. Consequently, the development of blast-resistant or blastworthy structures for armored fighting vehicles (AFVs) as blast-load mitigation remains critical. As blast load and IEDs become more powerful, the blastworthy structures of AFVs must be increasingly resilient to withstand such threats. Various methods for blast-loading mitigation have been researched through analytical, numerical, and experimental methods. As the simplest structure, single plates have been widely studied regarding their response to blast loading [3; 4; 5; 6]. To enhance blastworthiness performance, modifications to single plates have been explored, such as adding stiffeners [7; 8] and altering the flat plate to a V-shape [9; 10]. However, single plates are insufficient for mitigating extreme blast loading. One of the most effective alternative blastworthy structures is the sandwich panel. Sandwich panels are composite materials in which two or more different materials are combined at a macroscopic scale to produce a new material with superior performance compared to the constituent materials [11]. A sandwich panel consists of two thin, rigid face sheets bonded to a thick, lightweight core. This hybrid design fundamentally increases the moment of inertia of the structure without significantly adding mass. Various core structures have been studied for sandwich panels under blast loading. For example, [PERSON] et al. [12] investigated the blast response of metallic square honeycomb sandwich panel (HSP) structures. The results showed that the deformation of the back face of the sandwich panel was 40-90% smaller than that of an equivalent solid plate. [PERSON] et al. [13] conducted experimental studies on the blast responses of metallic hexagonal HSPs. The introduction of the hexagonal HSP significantly decreased the structure's deflection. [PERSON] et al. [14] experimentally investigated the influence of geometric parameters of metallic trapezoidal corrugated-core sandwich panels subjected to blast loading. The results showed that increasing the sheet and cell thickness, as well as increasing the corrugated angle, enhanced the blast resistance. In addition to honeycomb and corrugated cores, aluminum foam has also proven effective as a core material in sandwich panels for withstanding blast loading. Numerous studies have examined aluminum foam sandwich panels (AFSPs) [15; 16; 17]; for instance, [PERSON] et al. [18] examined the behavior of AFSPs under blast loading experimentally, analytically, and numerically. The results demonstrated that using foam as a sacrificial layer can control the contact stress level, providing local protection to the structure. [PERSON] et al. [19] studied the responses of AFSPs under blast loading and found that the peak load of the sandwich panel was reduced by 61.54-64.69% compared to a single plate. Conventional honeycomb structures typically exhibit positive Poisson's ratio characteristics. Over the past three decades, there has been increasing interest in negative Poisson's ratio (NPR) or auxetic materials due to their unique and contrasting properties compared to conventional materials. These auxetic materials are a prime example of metastructures, which are artificially designed structures with specific geometrical arrangements leading to unusual physical and mechanical properties. Auxetic structures, as a subset of metastructures, expand in all directions when stretched and contract when compressed.