Dynamic Fracture of Ceramics in Armor Applications

Abstract

Ceramic materials have been extensively used in armor applications for both personnel and vehicle protection. As the types of threats have diversified recently, e.g., improvised explosive devices and explosively formed projectiles, a proper set of ceramic material selection criteria is needed to design and optimize corresponding mitigating structures. However, the dynamic fracture and failure behavior of engineering ceramics is still not well understood. Using examples of thin ceramic plates and confined thick ceramics subjected to kinetic energy projectile impact, this article provides a brief summary on the current understanding of dynamic failure processes of ceramics under dynamic penetration loading conditions. Laboratory examination of dynamic fracture of ceramics is conducted using split Hopkinson bars with various loading rates, stress states, and loading histories.

Inelastic deformation and energy dissipation in ceramics: A mechanism-based constitutive model

“…Moreover, fracture is suppressed at lower levels of triaxiality. Indeed, typical armor ceramics with d$3 mm display some plasticity even under uniaxial compression (Chen et al, 2007).…”

The compressive failure of aluminum nitride considered as a model advanced ceramic

“…The piezoelectric properties of the single crystal are used in a variety of devices, including transducers, microwave filters, MEMS resonators, sensors and actuators (Bu et al, 2004;Dubois and Muralt, 1999;Martin et al, 2000; Trolier-McKinstry and Muralt, 2004;Zheng et al, 1993). Bulk polycrystalline aluminum nitride is generally not easily poled and so is not used for piezoelectric applications, but has found use in armor applications (Chen et al, 2007;Orphal et al, 1996) both as a standalone material and as part of ceramic composites (particularly with SiC).…”

Fabrication and dynamic compressive response of laminated ZrO–Zr2CN/Si3N4 ceramics

“…7a shows the representative high-strain-rate compressive true stress-true strain curves of the laminated ceramics at various strain rates from 1.1 Â 10 3 s À 1 to 3.5 Â 10 3 s À 1 . The compressive stress-strain curves exhibit universal four deformation regions: inelastic loading region, stable loading region, pseudoplastic deformation region and failure region, which is different from that of bulk ceramics [2] and [33] but similar to that of tungsten heavy alloys [34]. Initially, the laminated ceramics suffered plastic deformation under fairly low stress, with σo300 MPa at lower high-strain-rates of 1.1-2.0 Â 10 3 s À 1 or σo30 MPa at higher high-strain-rates of 2.7-3.5 Â 10 3 s À 1 .…”