In this study, a numerical triaxial compression test was carried out to investigate the influence of contact friction on the breakage behavior of brittle granular materials using the 3D discrete element method. An commercial software named Particle Flow Code 3D (PFC3D) was applied to undertake these simulations. The cubic numerical model was 30mm wide, 30mm long, and 30mm high, and contained 56...

Transition metal dichalcogenides have a layered structure and are therefore promising self-lubricating films. They can be considered as potential substitutes for carbon based films in various environmental conditions. In this work, a comparative atomic force microscopy study of co-sputtered Mo–Se–C and W–S–C films is performed to evaluate their nanotribological performances. Both films are allo...

This paper examines the forced convection flow of incompressible, electrically conducting viscous fluid past a sharp wedge in the presence of heat generation or absorption with an applied magnetic field. The system of partial differential equations governing Falkner Skan wedge flow and heat transfer is first transformed into a system of ordinary differential equations using similarity transform...

STATEMENT OF PROBLEM Loosening or fracture of the abutment screw are frequent complications in implant dentistry and are detrimental to the long-term success of the restorations. However, little is known about the factors influencing the stability of the screw-abutment complex. PURPOSE The purpose of this study was to investigate the influence of lubricant action during implant assembly on sc...

Acceleration–force setups for multi-rigid-body dynamics are known to be inconsistent for some configurations and sufficiently large friction coefficients (a Painleve paradox). This difficulty is circumvented by time-stepping methods using impulse-velocity approaches, which solve complementarity problems with possibly nonconvex solution sets. We show that very simple configurations involving two...

The friction coefficients of thin KCl films deposited onto clean iron in ultrahigh vacuum are measured using a tungsten carbide tip. A rapid decrease is found in the friction coefficient from 2 for clean iron to 0:27 0:03 after the deposition of 40 A of KCl. Based on previous contact resistance measurements, this was proposed to be due to the completion of the first layer of KCl. The firstlayer...

Retropatellar complications after total knee arthroplasty (TKA) such as anterior knee pain and subluxations might be related to altered patellofemoral biomechanics, in particular to trochlear design and femorotibial joint positioning. A method was developed to test femorotibial and patellofemoral joint modifications separately with 3D-rapid prototyped components for in vitro tests, but material...

Many stick insects and mantophasmids possess tarsal 'heel pads' (euplantulae) covered by arrays of conical, micrometre-sized hairs (acanthae). These pads are used mainly under compression; they respond to load with increasing shear resistance, and show negligible adhesion. Reflected-light microscopy in stick insects (Carausius morosus) revealed that the contact area of 'heel pads' changes with ...

Reach-to-grasp movements change quantitatively in a lawful (i.e. predictable) manner with changes in object properties. We explored whether altering object texture would produce qualitative changes in the form of the precontact movement patterns. Twelve participants reached to lift objects from a tabletop. Nine objects were produced, each with one of three grip surface textures (high-friction, ...

A new generation of experiments on dry macroscopic friction has revealed that the transition from static to dynamic friction is essentially a spatially and temporally non-uniform process, initiated by a rupture-like detachment front. We show the suitability of the FrenkelKontorova model for describing this transition. The model predicts the existence of two types of detachment fronts, explainin...