### Experimental Setup  
The first part of the experiments was conducted using the launcher of the Accredited Ballistic Applications Laboratory (ABAL) at the department of ballistics at the Royal Military Academy [21]. It allows impact of a target with a fragment-simulating projectile with a user-defined range of velocities. A universal receiver houses a barrel corresponding to each projectile to be pyrotechnically propelled's caliber. The layout of the experimental setup is shown in Figure 1.  
Two FSP calibers were used for the different tests: 7.62 mm and 12.7 mm. They were accelerated up to \(\pm\)325 m/s by means of a powder gun. The FSP dimensions were taken from STANAG-NATO [22] and are described in Figure 2a,b. The FSP in-flight velocity was measured by a double infrared velocity screen placed 2 m from the muzzle of the launcher. The distance was chosen to avoid interference with the muzzle flow that may trigger the counter of the velocity gates [23]. The system consisted of two sets of infrared gates. Each set was connected to a counter which recorded the time elapsed between the projectile passage through both gates. The FSP's initial velocity was chosen to be higher than the target's ballistic limit velocity. This choice limited the deformation to a small region around the impact point. The aluminum plates (commercial code \(EN\)-\(AW\)-1050\(A\)-\(H24\)) [24] were fixed to a steel frame. They were positioned at a distance of 5 m from the launcher. The selected plate thickness is intended to create localized plastic deformation around the impact point while facilitating energy dissipation through deformation under blast loading. Table 1 provides the material properties and plate dimensions.  
The aluminum sheet was a commercial aluminum alloy that belongs to the 1000 series aluminum alloys. The aluminum alloy was strain hardened and partially annealed, giving it moderate strength and improved formability. The material was annealed at a low temperature to relieve stress and prevent further strain hardening. The central part of the aluminum specimens was painted by application of a white background and a black speckle pattern as shown in Figure 2c. A study was conducted to determine the optimal speckle pattern parameters for the setup.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Material** & **Composition** & **Density** & **Young’s Modulus** & **Poisson’s Ratio** & **Plate Dimensions** \\  & & [kg/m\({}^{3}\)] & [GPa] & [-] & [mm \(\times\) mm \(\times\) mm] \\ \hline Al & 1050 A & 2710 & 69 & 0.33 & \(400\times 400\times 2\) \\ \hline \hline \end{tabular}
\end{table}
Table 1: Material properties and plate dimensions.  
Figure 1: Schematic representation of the experimental setup for fragment impact loading using fragment-simulating projectiles (Video S1).  
During the experiments, the plate behavior was observed using a field of view of 300 mm \(\times\) 300 mm. Two Photron Fastcam \(SA5\) high-speed cameras HSC (cameras 2 and 3) were mounted in a stereoscopic configuration to record synchronized images during the impact process. The high-speed cameras were placed behind a shield detector at a safe distance from the plate in order to avoid damage from the projectiles. Two light-emitting diodes LEDs were used to increase the illumination of the aluminum plate. This was performed to maintain adequate contrast throughout the experiment.