Highly ordered, close packed granular systems present a nonlinear dynamic behavior stemming from the Hertzian contact interaction between particles. We investigated the propagation of elastic stress waves in an uncompressed, centered square array of spherical and cylindrical particles. We show, via experiments and numerical simulations, that systematic variations of the mass and stiffness ratio...

We investigate the dynamics of a chain of oscillators coupled by fullynonlinear interaction potentials. This class of models includes Newton’s cradle with Hertzian contact interactions between neighbors. By means of multiple-scale analysis, we give a rigorous asymptotic description of small amplitude solutions over large times. The envelope equation leading to approximate solutions is a discret...

Hertzian line contact stresses between a rotat ing metal cy l inder and a reciprocating f lat str ip of the bearing material are used in an accelerated wear test described in this paper. The test readi ly demonstrates differences in the wear behaviour between d i f ferent PTF E-based dry bearing materials. For one widely-used woven PTFE f ibre composite, the relat ionships between wear and stre...

Simple relations for the onset of competing brittle and quasiplastic damage modes in Hertzian contact are presented. The formulations are expressed in terms of well-documented material parameters, elastic modulus, toughness, and hardness, enabling a priori predictions for given ceramics and indenter radii. Data from a range of selected ceramic (and other) materials are used to demonstrate the a...

We report the experimental observation of modulational instability and discrete breathers in a one-dimensional diatomic granular crystal composed of compressed elastic beads that interact via Hertzian contact. We first characterize their effective linear spectrum both theoretically and experimentally. We then illustrate theoretically and numerically the modulational instability of the lower edg...

Indentation testing of a brittle material using a notionally `sharp' indenter may reveal several important physical properties, including fracture toughness, surface ®nish information and the residual stress state. In the case of shallow cone indenters, the contact and fracture mechanics is well de®ned and closed-form solutions exist in elasticity theory. However, no real indenter is atomically...