text: Sandwich panel cores are used throughout the aerospace industry; they are integrated within aircraft bodies, floors and internal panels. Sandwich constructions consist of two faces separated by a thick, light-weight core and are most commonly composed of balsa-wood, foamed polymers, glue-bonded aluminum or Nomex (paper) honeycombs. Typically, the cores are combined with reinforcing fibers to increase their shear modulus. Indeed, carbon fiber-reinforced polymers exhibit the highest specific stiffness and strength of these materials. However, polymers decompose at low temperatures; thus employment of the aforementioned materials pose inherent challenges due to the limited range of temperature they may be utilized within as well as their moisture-dependent properties.
  The largest and most inadequately predicted failure within the core results from strain localization. Strain localization refers to the development of bands exhibiting intensive straining as a result of the localization of deformations in the solid.
   For the best performance, the structure should exhibit low peak response force and high total energy absorption. Titanium foams are lightweight, stiff, and possess the capability to resist blast. Furthermore, the use of titanium-based foams exhibiting homogeneous porosity distribution would significantly decrease the risks associated with strain localization. The high strength-to-weight ratio of titanium foams offers an opportunity to provide increased bending and shearing stiffness as well as energy absorption capabilities during periods of bending. Titanium foams may be utilized in environments with elevated temperatures (up to 400 °C). Composite structures may also be produced; the incorporation of silicon carbide monofilaments into Ti-6-Al-4V foams was shown to exhibit an elastic modulus of 195 GPa and tensile strength of 800 MPa.