High impact velocity on multi-layered composite of polyether ether ketone and aluminium

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.

Section: Thermoviscoplastic Behaviormentioning

confidence: 99%

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

Garcia‐Gonzalez

Rusinek

et al. 2018

Metals

“…where the Quinney-Taylor coefficient, which defines the percentage of plastic work converted into heat, was taken to be equal to β = 0.9 [30,31]. Table 6.…”

Section: Numerical Modelmentioning

confidence: 99%

Thermo-Viscoplastic Behavior of Ni-Based Superalloy Haynes 282 and Its Application to Machining Simulation

Díaz-Álvarez

Bernier

et al. 2017

Metals

Abstract:Ni-based superalloys are extensively used in high-responsibility applications in components of aerospace engines and gas turbines with high temperature service lives. The wrought, γ'-strengthened superalloy Haynes 282 has been recently developed for applications similar to other common superalloys, such as Waspaloy or Inconel 718, with improved creep behavior, thermal stability, and fabrication ability. Despite the potential of Haynes 282, there are still important gaps in the knowledge of the mechanical behavior of this alloy. In fact, it was not possible to find information concerning the mechanical behavior of the alloy under impulsive loading. This paper focuses on the mechanical characterization of the Haynes 282 at strain rates ranging from 0.1 to 2800 s −1 and high temperatures ranging from 293 to 523 K using Hopkinson bar compression tests. The experimental results from the thermo-mechanical characterization allowed for calibration of the Johnson-Cook model widely used in modeling metallic alloy's responses under dynamic loading. Moreover, the behavior of Haynes 282 was compared to that reported for Inconel 718, and the results were used to successfully model the orthogonal cutting of Haynes 282, being a typical case of dynamic loading requiring previous characterization of the alloy.

“…However, Kammoun et al [15] have suggested, due to the limitations of this assumption, the selected failure criteria would only reveal approximate trends and they recommend the development of more appropriate 3D failure criterion. Following their 11 recommendations a Tsai-Hill failure criterion has been programmed in a VUMAT subroutine in order to establish a damage initiation criterion considering the 3D formulation, Eq. 3.…”

Section: Damage Initiation Criterionmentioning

confidence: 99%

“…Mechanical impact process is a complex problem that includes dynamic behavior, fracture, damage, contact and friction [10,11]. For PEEK composites, interesting thermo-mechanical phenomena have been reported associated with high strain rate in dynamic process: changes in ductile-brittle transition, toughness, fracture energy and failure mechanisms [12,13].…”

Section: Introductionmentioning

confidence: 99%

Investigation of mechanical impact behavior of short carbon-fiber-reinforced PEEK composites

Garcia‐Gonzalez

Rusinek³

et al. 2015

Composite Structures

Self Cite

109

Investigation of mechanical impact behavior of short carbon-fiber-reinforced PEEK composites, Composite Structures (2015), doi: http://dx.Abstract. This paper describes the results of an experimental and numerical investigation of the impact behavior of short carbon fiber reinforced polyether-ether-ketone (SCFR PEEK) composites. The biocompatibility of PEEK and its short fiber composites, their rapid processing by injection molding and suitability for modern imaging have supported technological advances in prosthetic implants used in orthopedic medicine. Surgical implants, including hip and cranial implants, can experience clinically significant impact loading during medical installation and useful life. While the incorporation of short fibers in a thermoplastic matrix can produce significant improvements in stiffness and strength, it can also cause a marked reduction in ductility, making study of their energy absorption capability essential. In this work, the mechanical impact behavior of PEEK composites reinforced with polyacrylonitrile (PAN) short carbon fibers 30 % in weight is compared with unfilled PEEK. The perforation tests conducted covered an impact kinetic energy range from 21 J to 131 J, equivalent to the range observed in a fall, the leading cause of hip fractures. Energy absorption capability, damage extension and failure mechanism have been quantified and reported. A numerical modeling that includes homogenization of elastic material and 1 anisotropic damage is presented and validated with experimental data. At all impact energies, SCFR PEEK composites showed a brittle failure and their absorption energy capability decreases drastically in comparison with unfilled PEEK.