Numerical Simulation Study on Failure Zones and Attenuation Behavior of Stress Waves of Cylindrical Charge Explosions in Concrete

In the past, the design of structures resistant to conventional weapons has largely focused on the study of explosion stress waves in solid media, particularly in soil and rock media (i.e., ground shock issues), while the research on the propagation and attenuation of explosion stress waves in concrete remains relatively scarce. To investigate the propagation behavior of stress waves in the near-field of cylindrical charge explosions in concrete, this paper conducts a numerical simulation study based on the KCC constitutive model and the MM-ALE algorithm. Firstly, the applicability of the constitutive model parameters and numerical algorithm is validated by comparing the results with existing experimental data. Subsequently, the impact of charge shape on the explosion failure zone and the propagation behavior of explosion-induced stress waves is analyzed, and a formula for calculating the peak stress of stress waves generated by cylindrical charge explosions is established. Finally, a stress peak coupling coefficient is introduced to quantitatively analyze the impact of burial depth on the distribution of normal peak stress in explosion-induced stress waves. It was found that the attenuation patterns of explosion-induced stress waves differ significantly across various explosion failure zones. In comparison to the mid-field zone (transition and fracture zones), the near-field zone (quasi-fluid and crushing zones) exhibits faster attenuation. Additionally, an increase in the length-to-diameter ratio of the cylindrical charge accelerates the attenuation of normal peak stress. Moreover, the established formula for calculating the peak stress of explosion-induced stress waves enables accurate and rapid calculate of the normal peak stress for cylindrical charges with different length-to-diameter ratios and burial depths. This empirical formula can serve as a valuable reference for blast-resistant design of concrete structures.