Numerical study and experimental validation of blastworthy structure using aluminum foam sandwich subjected to fragmented 8 kg TNT blast loading

• Published in: International journal of impact engineering 2020-12, Vol.146, p.103699, Article 103699
• Main Authors: Pratomo, Arief N., Santosa, Sigit P., Gunawan, Leonardo, Widagdo, Djarot, Putra, Ichsan S.
• Format: Article
• Language: English
• Subjects: Acceleration; Aluminum; Aluminum foam sandwich; Blast experimental setup; Blast loads; Blasting (explosive); Blastworthy structure; Damage assessment; Deformation; Explosions; Fractures; Fragmented explosion; Impact loads; Impact tests; Injury prevention; Mathematical models; Metal foams; Numerical analysis; Sandwich panels; Sandwich structures; Shock waves; Stability; Steel-covered TNT; Structural damage; Structural integrity
• ISSN: 0734-743X; 1879-3509
• DOI: 10.1016/j.ijimpeng.2020.103699

•Experimental validation on the blastworthy characteristics of Al-foam sandwich panel.•The Al-foam sandwich panel subjected to steel-covered 8 kg-TNT blast load.•The fragmented explosion created a ring-shaped hole damage mode.•FE with smooth particle hydrodynamic model achieved a good agreement with the test.•The structural integrity of the occupant side plate during explosion was maintained. A blastworthy structure is defined as a structure that has the ability to deform with a controlled force and preserve sufficient residual space around the occupants to limit bodily injury during a blast impact incident. In this research, a blastworthy aluminum foam sandwich (AFS) structure that consisted of an occupant side plate (OSP), a struck side plate (SSP), and an aluminum foam (Al-foam) core were numerically and experimentally subjected to blast-fragmented loading. The explosion with high-pressure shock waves was produced by steel-covered TNT, creating a synergistic blast and fragment loading. The interaction between the blast-fragment loading and the AFS created a unique perforation pattern due to Monroe's effect. The measured blastworthiness characteristics included structural integrity, acceleration, and reaction force. A numerical modeling strategy to analyze the blastworthiness performance of the AFS structure was developed to capture the dynamic responses and the damage mechanism. Two types of blast loading, namely load blast enhanced (LBE) and smooth particle hydrodynamic (SPH) blast loading, were utilized along with the Cockcroft-Latham damage modeling on the AFS. A blast experimental setup with a fix-clamped method was used to evaluate the blastworthy characteristics of the panel to acquire the central acceleration and reaction force histories. A two-step process of experimental validation was carried out. First, a pre-test system validation with a very low explosive blast using 60 gram of TNT was conducted on the sandwich specimen to ensure the data acquisition system's functionality and to obtain comparable data for system validation. Second, a blast impact test using 8 kg of steel-covered TNT was carried out to validate the numerical modeling results. The results of the numerical analysis showed that the LBE model had good agreement with the test data for the small deformation blast impact loading with 60 gram TNT. For the large deformation blast impact loading with 8 kg TNT, the SPH models provided excellent agreement with the damage mode and dynam