Failure analysis through fragmentation behaviour of Al 2024 alloy subjected to high strain Rates- experimental and numerical studies. (July 2023)

• Record Type: Journal Article
• Authors: Gara, Navya; Jayaganthan, R.; Velmurugan, R.
• Is Part Of: Engineering failure analysis. Volume 149(2023)
• Publication Date: 2023-07
• Subjects: Al2024 alloy -- Fragmentation -- Energy absorption -- Deformation mechanisms -- Strain rates, FEA; System failures (Engineering) -- Periodicals; Fracture mechanics -- Periodicals; Reliability (Engineering) -- Periodicals; Pannes -- Périodiques; Rupture, Mécanique de la -- Périodiques; Fiabilité -- Périodiques; Fracture mechanics; Reliability (Engineering); System failures (Engineering); Periodicals; Electronic journals; 620.112
• DOI: 10.1016/j.engfailanal.2023.107258
• Languages: English
• ISSNs: 1350-6307

Abstract

Research highlights: The best ballistic impact resistance of Al2024-T3 & Al2024-T3+T6 alloy was with blunt and ogive & hemi-spherical projectiles, respectively. Ogive projectile was found to be a very effective penetrator for the two alloy conditions through the experimental and numerical studies. Kinetic Energy Absorption of Al2024-T3 was higher as compared to Al2024-T3+T6 condition. For all cases, NSM has shown a comparable and realistic prediction of the ballistic limit velocities, and kinetic energy absorption than CEM. Abstract: The failure mechanisms through fragmentation and their effect on the Al2024 alloy and its temper condition when subjected to high strain rates experienced in aerospace and defence applications are scarce in the literature. The present work deals with the investigation of as-received Al2024- T3 and its temper condition Al2024-T3 + T6 subjected to the ballistic impact on single stage gun in the velocity range of 50–250 m/s for their deformation behaviour. Three types of nose-shaped projectiles- blunt, hemispherical and ogive were triggered onto 3 mm target plates in the normal direction. The difficulty in retrieving the fragments during the experimental investigations motivated the perception of the numerical analyses. Two approaches such as the Conventional Erosion Model (CEM) and Node Separation Model (NSM) on LS DYNA software were developed and adopted. The residual velocities, Ballistic Limit Velocities (BLV), Kinetic Energy Absorption (KEA) and their deformation mechanisms were compared and analysed for the two target alloy conditions to obtain better ballistic-resistant material. Ogive projectile has shown to be the best penetrator for the alloy materials and additionally, the KEA for the tempered condition was higher compared to the Al2024-T3 and Al2024-T3 + T6 just above the BLV. The NSM methodology for fragmentation analysis has been proved to be a promising technique and the estimates were comparable and realistic to those of experimentally obtained estimates.