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Polyvinyl butyral (PVB) laminated glass is widely used in architectural structures and automotive glass due to its remarkable cushioning and cohesive properties, and its lamination thickness has a significant effect on the overall impact resistance of the glass. In this paper, two conventional laminated glass thicknesses of 0.76 mm and 1.52 mm were selected to study the dynamic performance and damage morphology of laminated glass under three different impact velocities using light gas gun impact tests combined with industrial CT scanning-3D reconstruction techniques. The results showed that the PVB sandwich thickness had a significant positive correlation with the energy absorption effect, but under different impact velocities and glass thickness, the sandwich thickness and impact resistance showed a differentiated "marginal effect". At moderate impact velocities, the impact resistance was most sensitive to the change in sandwich thickness. With the increase in glass thickness, the sensitivity of impact resistance to the change of sandwich thickness decreased. According to the characterization of full-dimensional cracks under medium-velocity impact conditions, it could be seen that the sandwich had the function of buffering dissipation and gathering recovery in different stress directions, and the thickness of the sandwich was a key functional parameter to reduce the flying of glass fragments. Therefore, the results of this study can provide a reference for the analysis and design of the impact resistance of PVB laminated glass. [ABSTRACT FROM AUTHOR]

For explosion-proof and effective suppression measures in treating magnesium–aluminum alloy, it is of great importance to study the suppression of Mg–Al alloy dust explosions to prevent explosion disasters. The addition of inert solid substances to combustible dust is a measure aimed at preventing and reducing dust explosions. The explosion characteristics and flame propagation characteristics of Mg–Al alloy powder were studied using the Hartmann tube 20 L spherical explosion experimental system. The mechanism for removing sodium bicarbonate (NaHCO3) during the Mg–Al alloy powder explosion was further studied. The results show that the explosion pressure, the height of the deflagration flame, and the speed at which the flame propagates can be effectively reduced by increasing the percentage of NaHCO3. After the addition of 80% NaHCO3, the flame was suppressed, and the maximum explosion pressure decreased to less than 0.1 MPa, causing a 93% decrease in the maximum flame propagation speed. The process of suppressing NaHCO3 powder on magnesium aluminum alloy dust explosion is relatively complex, starting primarily with physical and chemical suppression. NaHCO3 realizes physical inhibition by reducing ambient temperature and oxygen concentration through the H2O and CO2 generated by decomposition. At the same time, through the cycle of NaO ↔ Na, the transformation from highly active oxygen to low active oxygen is realized. This reduces the activity of the explosive combustion response of Mg–Al alloy powder. At the same time, sodium ions can capture free radicals in explosive responses, reducing the number of free radicals in the reaction system and terminating the combustion reaction chain in advance. The research findings are of great importance for the safety of Mg–Al alloy production. [ABSTRACT FROM AUTHOR]

A new energy material, a high-energy expansion agent (HEEA), was proposed for the harsh engineering environment of a mine. A safety test and field engineering test were carried out. The results showed that the mechanical sensitivity of the HEEA was extremely low, and no combustion and explosion occurred in multiple impact and friction tests. Meanwhile, the HEEA only burns in open spaces without detonation. Through field experiments, the HEEA can achieve a good blasting effect, providing strong support for its promotion in low-disturbance environmental engineering applications. [ABSTRACT FROM AUTHOR]