Dynamic Behaviour of Metallic Hollow Sphere Structures

Abstract

The chapter focuses on the dynamic behaviour of metallic hollow sphere structures that constitute an innovative group of lightweight materials, combining high specific stiffness, good damping properties and the ability to absorb large amounts of energy at a constant low stress level. The chapter explains the methodology and results of computational experimenting to clarify and determine the individual influences on the macroscopic behaviour of MHSS, especially under dynamic loading conditions. In the beginning, the material strain rate dependency is described and formulated with several constitutive models. A very important factor at impact loading is material deformation capability and impact energy absorption, which directly influences the deceleration of impacting objects. The impact energy absorption of hollow sphere structures due to their plastic deformation under impact loading is emphasized. The second part of this chapter presents the computational results of metallic hollow sphere structures and their macroscopic behaviour under uniaxial dynamic loading conditions with additional material characterisation considering large strains. Furthermore, the influence of gas inside the metallic spheres on behaviour of metallic hollow sphere structures and their capability of impact energy absorption is addressed. Computational simulations show that it is possible to achieve different dynamic response of metallic hollow sphere structures when subjected to dynamic loading. The topology, wall thickness of spheres and strain rate sensitivity can be combined in a way that the structure response is adapted to a given engineering problem. The chapter concludes with a discussion of the advantages, disadvantages and limitations of dynamically loaded metallic hollow sphere structures and their computational models.