Failure behavior of 2024-T3 aluminum under tension-torsion conditions

Garcia‐Gonzalez

Rusinek

et al. 2018

Thin-Walled Structures

This paper focuses on the mechanical behaviour of aluminium alloy 2024-T351 under impact loading. This study has been carried out combining experimental and numerical techniques. Firstly, experimental impact tests were conducted on plates of 4 mm of thickness covering impact velocities from 50 m/s to 200 m/s and varying the stress state through the projectile nose shape: conical, hemispherical and blunt. The mechanisms behind the perforation process were studied depending on the projectile configuration used by analyzing the associated failure modes and post-mortem deflection. Secondly, a numerical study of the mechanical behaviour of aluminium alloy 2024-T351 under impact loading was conducted. To this end, a three-dimensional model was developed in the finite element solver ABAQUS/Explicit. This model combines Lagrangian elements with Smoothed Particle Hydrodynamics (SPH) elements. A good correlation was obtained between numerical and experimental results in terms of residual and ballistic limit velocities.

Section: Sph Conversion Criterionsupporting

confidence: 76%

Section: Methodsmentioning

confidence: 99%

Perforation mechanics of 2024 aluminium protective plates subjected to impact by different nose shapes of projectiles

Garcia‐Gonzalez

Rusinek

et al. 2018

Thin-Walled Structures

“…The failure locus has been constructed as a function of stress triaxiality and the third invariant of the stress deviator, confirming the combined void-shear nature of the failure. This methodology has been successfully developed on AA 2024-T351 in a previous work [17].…”

Section: Experimental Methodologymentioning

confidence: 99%

Influence of Stress State on the Mechanical Impact and Deformation Behaviors of Aluminum Alloys

Garcia‐Gonzalez

Rusinek

et al. 2018

Metals

Under impact loading conditions, the stress state derived from the contact between the projectile and the target, as well as from the subsequent mechanical waves, is a variable of great interest. The geometry of the projectile plays a dertermining role in the resulting stress state in the targeted structure. In this regard, different stress states lead to different failure modes. In this work, we analyze the influence of the stress state on the deformation and failure behaviors of three aluminum alloys that are commonly used in the aeronautical, naval, and automotive industries. To this purpose, tension-torsion tests are performed covering a wide range of stress triaxialities and Lode parameters. Secondly, the observations from these static tests are compared to failure mode of the same materials at high impact velocities tests with the aim of analysing the role of stress state and strain rate in the mechanical response of the aluminum plates. Experimental impacts are conducted with different projectile geometries to allow for the analysis of stress states influence. In addition, these experiments are simulated by using finite element models to evaluate the predictive capability of three failure criteria: critical plastic deformation, Johnson-Cook, and Bai-Wierzbicki.

“…For the simple conical geometries, the ballistic limit increases with the nose angle of the projectile. This is generally observed in most metals although it has been shown that there may be exceptions due to the influence of the triaxiality and the Lode parameter on plasticity and failure strain [8,27,28]. For the case of 72°, the double-nose plays an important role because it reduces the perforation resistance of the plate by 10% ( 118 / for simple conical projectile and 106 / for double-nose projectile).…”

Section: Ballistic Limitmentioning

confidence: 96%

Experimental and Numerical Analysis of Conical Projectile Impact on Inconel 718 Plates

Díaz-Álvarez

Bernier

et al. 2019

Metals

Self Cite

This paper analyses the impact behavior of Inconel 718 through experimental and numerical approach. Different conical projectiles were tested in order to obtain the ballistic curves and failure mechanisms. A three-dimensional (3D) numerical model corresponding to the experimental tests was developed using the Johnson–Cook constitutive model. The experimental data (residual velocities, global, and local perforation mechanisms) were successfully predicted with the numerical simulations. The influence of the projectile’s nose angle was found to be important when designing ballistic protections. The projectile with the narrowest angle, 40°, developed a ballistic limit approximately 10 m/s lower than the projectile with a 72° nose. The use of double-nose projectile for the same nose angle, 72°, led to a ballistic limit 12 m/s lower than that obtained for the single nose.