A numerical simulation method for fragments distribution of concrete subjected to blast loading

Concrete is widely employed in the construction of buildings and critical infrastructure, however, such structures are highly vulnerable to blast loads during their service. The concrete structures undergo fracture and fragmentation failure when subjected to blast loading, the resulting secondary concrete fragments possess substantial kinetic energy and destructive potential, capable of inflicting significant collateral damage to personnel and equipment within the affected area. This study focuses on high-energy secondary fragments generated under blast loading, a numerical investigation is conducted using the LS-DYNA simulation software, the high explosive model, air medium model, and concrete Karagozian&Case (KC) material model are integrated with the Arbitrary Lagrangian–Eulerian (ALE) method to simulate concrete fragmentation behavior under multiple blast scenarios. The fragmentation morphology is characterized for both lateral and top detonation, furthermore, a specialized analysis plugin is developed through secondary programming to complete the identification and data output for concrete fragments across various particle sizes. The effective extraction and quantitative statistics methods for fragmentation parameters information are proposed, moreover, the accuracy of the present numerical simulation method is verified with the comparative of the experimental and theoretical results. Parametric analysis are performed to investigate the influence of concrete strength grade and charge mass on fragmentation behavior, the quantitative distribution and percentage composition of secondary fragments are determined in different particle size ranges. The identification statistical program and fragmentation information extraction method developed in this study can solve the problems for quantitative prediction on concrete fragmentation behavior, which are meaningful for the damage assessment and mining engineering.