###### Abstract
The latter introduced plastic deformation and petalling cracks to the material around the impact zone. During blast loading, a propagation of the petalling cracks was observed. A reduced fracture resistance was found in the case of plates with ballistic impact perforation. More recently, [PERSON] et al. [20] compared two experimental techniques for generating combined loading. In the first, steel plates with pre-formed holes at the plate center were exposed to pressure pulses. In the second, intact plates were exposed to sequential single-fragment impact and blast loading using a composite projectile fired from a gas gun facility. The composite projectile consisted of a closed-cell metallic foam and an embedded fragment-simulating projectile (FSP) where the FSP mimics the fragment impact on the plate and the foam simulates the applied blast loading. The central deflection, the failure modes, and the deformation processes of target plates obtained from the analysis of the two experimental techniques were compared. It was found that plates subjected to composite projectile impact at high impact velocity are more susceptible to tearing fracture. Therefore, specific cases exist where the idealization of an FSP impact as a pre-formed hole in the target will under-predict the actual damage caused by sequential FSP impact and blast loading. Although the proposed experimental technique highlights the influence of the fragment impact velocity on the plates' tendency to fracture, the conclusions only hold for the case of a single fragment impact. Thus, it is still desirable to extend their applicability by investigating other influencing parameters such as the number of perforations and the hole spacing. The aforementioned studies on structures and materials provide insights into (i) the different approaches and experimental techniques used to replicate combined blast and fragment impact loading, (ii) the encountered challenges in generating a reproducible loading, and (iii) the response of the different targets with respect to fragment impact, blast, or both loadings. This study has three main objectives: (i) contribution to the knowledge of how deformation and damage in plate-like materials subjected to a consecutive loading of fragment impact and blast wave are affected by projectile parameters such as size, shape, and number; (ii) investigation of the influence of the relative distance between impacts (hole spacing) on the fracture resistance during blast loading; and (iii) establishment of a comprehensive experimental data set that allows the development of computational methods for numerically investigating the dynamic behavior of plates exposed to the combined effect of blast and fragment impact loading. The proposed test method in the present work is based on exposing thin aluminum plates to the impact of either a single or three FSPs. Subsequently, the perforated plates are subjected to a controlled planar blast wave via an explosive-driven shock tube. Stereoscopic high-speed digital image correlation (DIC) is used for result analysis. This technique enables focus on: (i) the local deformation on the impact zone activated by the fragment impact and (ii) the global deformation due to the blast loading. Dynamic Behavior of Thin Aluminum Plates Subjected to the Impact of Fragment-Simulating Projectiles