Discrete particle simulations are by now well established as an effective tool to study the mechanics of complex gas-solid flows in gas-fluidized beds. In this study, a state-of-the-art discrete particle model is used to explore the role of particle-particle interactions in bubbling gas-fluidized beds of Geldart A particles. We find that the particle-particle interactions, including inelastic p...

There are several types of firing tests of cannonballs. In ground firing tests, cannonballs without gunpowder charged are fired against sand heap. When a cannonball collides into sand, the cannonball’s penetration depth, stress and sand temperature depend on the sand properties. Sand tends to become harder than before after plenty of cannonball firing. This is because kinetic energy of a cannon...

INTRODUCTION The reflection and refraction of horizontally polarized shear (SH) waves by a frictional contact interface that can slip has been studied by the present authors [l-3] and Miller [4-6]. If the solids are sheared, the localized slip induced by the waves is more pronounced in one direction than in the other, which leads to the interesting phenomenon of the solids creeping with respect...

Cropping is a cutting process whereby opposing aligned blades create a shearing failure by exerting opposing forces normal to the surfaces of a metal sheet or plate. Building on recent efforts to quantify cropping, this paper formulates a plane strain elastic–plastic model of a plate subject to shearing action by opposing rigid platens. Shear failure at the local level is modeled by a cohesive ...

Wear is the progressive loss of material from the operating surface of a body occurring as a result of relative motion at the surface, while friction is the main means of controlling the input of energy in a system. The tribosystem approach proposes analysing the contact on both the material and the energetic planes, but the relationships between the different planes are not well established. I...

Damage to mechanical components caused by wear is considered to be an important issue for mechanical engineers. For the purpose of wear resistance, it is necessary to improve the material properties of the mechanical elements. Furthermore, low friction plays an important role in saving energy. Hence, it is important to establish a key technology for wear resistance and low friction through appr...

In this paper, comparisons of damage evolution between 2D C/SiC and SiC/SiC ceramic-matrix composites (CMCs) under tension-tension cyclic fatigue loading at room and elevated temperatures have been investigated. Fatigue hysteresis loops models considering multiple matrix cracking modes in 2D CMCs have been developed based on the damage mechanism of fiber sliding relative to the matrix in the in...

A study of architectural walls for energy dissipation and vibration control of buildings in seismic zones is presented. Typical architectural walls exhibit inelastic behavior; however, both the stiiness and energy dissipation capacity degrade after the walls are damaged. Integrating passive damping devices within these walls augments their energy dissipative abilities by widening the hysteresis...