PSI - Issue 72

Kevin Fabian Arsaputera et al. / Procedia Structural Integrity 72 (2025) 409–417

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2.1. Experimental methods and impact characterization Experimental methodologies for ballistic testing have undergone substantial refinement in recent years. Gupta et al. (2007) performed extensive investigations on the effects of projectile nose shape and impact velocity on aluminum target deformation. Their results indicated that hemispherical projectiles typically produce different failure mechanisms than flat-nosed projectiles, with the former showing a tendency toward ductile hole formation and the latter promoting plug formation. These findings were further supported by Wickert (2016), who utilized high-speed imaging techniques to capture the temporal evolution of deformation patterns during impact events. 2.2. Numerical simulation approaches The advancement of computational capabilities has enabled increasingly sophisticated numerical simulations of ballistic impact phenomena. Rahman et al. (2024) recently demonstrated the importance of considering attack angle variations in ballistic impact simulations, particularly for sandwich panel configurations. Their work highlighted the significance of proper material model selection and mesh refinement strategies in achieving accurate predictions. Implementing the Johnson-Cook constitutive model has proven particularly effective in capturing the material response under high strain-rate conditions, as validated by comparative studies by Goda and Girardot (2021). 2.3. Material response and failure mechanisms Understanding the failure mechanisms of aluminum plates under ballistic impact has been a focal point of recent research. Cavenagh et al. (2024) investigated the relationship between target thickness and penetration resistance, identifying critical thickness ratios and determining the transition between different failure modes. Their work complements earlier studies by Liu et al. (2023), who established correlations between impact energy and failure pattern development. The influence of thermal effects during high-velocity impact, particularly concerning adiabatic shear band formation, has been thoroughly examined by Swinea et al. (2023). 2.4. Energy absorption characteristics Recent investigations have focused on quantifying and optimizing the energy absorption capabilities of protective materials. Lu and Yu (2003) developed analytical models for predicting energy absorption in aluminum plates, incorporating geometric and material parameters. Their approach was validated through extensive experimental testing, showing good agreement between predicted and measured values. The work of Odeshi et al. (2005) further contributed to this understanding by examining the role of strain-rate effects on energy absorption mechanisms. 2.5. Explicit dynamic analysis Explicit dynamic analysis is a crucial computational method for simulating high-speed impact events and short duration dynamic problems. Prabowo et al. (2023) demonstrated that explicit time integration schemes are particularly effective for analyzing wave propagation phenomena and discontinuous contact problems typical in ballistic impact scenarios. The method's advantage lies in handling highly nonlinear material behavior and complex contact conditions without requiring iteration at each time step. Recent work by Tabiei and Tanov (2020) has shown that explicit dynamic analysis provides superior computa-tional efficiency compared to implicit methods for problems involving high-speed deformation. Their research highlighted that the explicit method's conditional stability, though requiring small time steps, is particularly well-suited for capturing stress wave propagation during ballistic impact events. This is especially relevant when ana-lyzing the dynamic response of protective structures, where stress wave interactions play a crucial role in energy dissipation. Haq and Narala (2024) further explored the application of explicit dynamics in analyzing failure mechanisms. Their work emphasized the importance of appropriate element formulation and hourglass control in preventing numerical instabilities, particularly in simulations involving severe material deformation. Integrating explicit dynamic analysis with advanced material models, such as the Johnson-Cook model, has proven essential for accurately predicting material behavior under extreme loading conditions.