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This study aimed to develop a structural analysis method to replace and validate large-scale gas gun tests for evaluating the impact resistance of electronic equipment. By measuring projectile's deceleration through experiments and simulations, stress and strain during collisions were quantified. It was demonstrated that optimizing projectile and electronic equipment designs could enhance impact resistance. Simulation results indicated that changes in projectile velocity and head angle led to variations in maximum deceleration and penetration depth, with decreasing the head angle proving more effective in reducing maximum deceleration. Comparisons between experimental and simulation results showed good agreement, particularly in plots between maximum deceleration and target collision depth. As the head angle increased, there was a tendency for maximum deceleration to increase and target penetration depth to decrease. Comparing peak deceleration curves from gas gun tests and simulations revealed similar trends, indicating consistent results. This research provides important information for evaluating the impact resistance of electronic equipment and demonstrates that combining experiments with simulations can yield more reliable results.

The configurational design of heterostructures has received considerable attention to achieve a superior combination of strength and ductility. Although heterostructuring for enhanced tensile properties has been widely analyzed, studies on the effect of heterogeneity on sheet formability are still insufficient. Sheet metal formability is one of the most crucial factors for determining hetero-materials’ industrial utilization. To broaden the industrial applicability of heterostructured layered materials, investigating the effects of heterogeneity in the layered structure on formability is necessary. This study investigated the stretch formability of aluminum-steel-aluminum clad sheets using the Erichsen cupping test. The three-layered clad sheets showed additional hardening with a slight increase in ductility owing to hetero-deformation-induced hardening because the strain-hardening exponent has a linear relationship with stretchability or necking resistance. After necking, damage evolution owing to severe internal stress concentration led to delamination at the interface. Interestingly, delamination serves as a block to full cracking through the thickness during forming. This study contributes to the industrial applicability of heterogeneous structuring by elucidating the characteristics of heterogeneity and formability.

In this study, the nano-to bulk-scale fracture behaviors of a dual phase (DP) steel were investigated by combining a micro-digital-image-correlation (micro-DIC) technique and the finite element method (FEM). The emergence of surface cracks and nano-to bulk-scale strain distributions during plastic deformations were investigated using micro-DIC and macro-DIC techniques. FEM simulations were conducted to calculate the stress state of the damaged regions that could not be directly obtained from experiments. By combining nano- and bulk-scale observations, fracture strain and stress triaxiality of both scales were determined into model parameters for predicting the material damage behavior. The accuracy of the present damage model parameters was confirmed by comparing the load–displacement curves obtained from experimental result and proposed method. This new strategy of combining micro-scale deformation behavior and bulk-scale damage analysis facilitates defining damage model parameters through observing a wide range of regions with only one or two specimens, which is opposed to the conventional method that requires bulk-scale observations in multiple loading condition.