Any macroscopic deformation of a filamentous bundle is necessarily accompanied by local sliding and/or stretching of the constituent filaments. Yet the nature of the sliding friction between two aligned filaments interacting through multiple contacts remains largely unexplored. Here, by directly measuring the sliding forces between two bundled F-actin filaments, we show that these frictional fo...

We report on detailed laboratory experiments designed to illustrate the frictional behavior of granular volcanic debris. The materials include pyroclastic flow debris from Soufrière Hills Volcano, Montserrat, and from Stromboli Volcano, Italy, and lahar deposits from Mount St. Helens. Experiments were conducted in a servo-controlled, double-direct shear apparatus under conditions of displacemen...

The field of tribology defined in Webster’s Dictionary as “a science that deals with the design, friction, wear and lubrication of interacting surfaces in relative motion” has a long and important history in science and technology[1]. The ancient Egyptians, for example, used water to lubricate the path of sleds employed to transport extremely heavy objects. The first scientific studies of frict...

Aluminum alloys are used in many applications in which the combination of high strength and low weight is attractive; ship building, air frame, transportation industry etc. are some areas in which the low weight can be significant value. Friction stir welding (FSW) is a new welding technique particularly well suited to aluminum alloys though this technique is also used for other materials. Fric...

Frictional vibration and noise caused by water-lubricated rubber stern tube bearings, which are generated under extreme conditions, severely threaten underwater vehicles' survivability and concealment performance. This study investigates the effect of flaky and spherical MoS2 nanoparticles on tribological properties and damping capacity of water-lubricated rubber materials, with the aim of decr...

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...

The field of tribology defined in Webster’s Dictionary as “a science that deals with the design, friction, wear and lubrication of interacting surfaces in relative motion” has a long and important history in science and technology[1]. The ancient Egyptians, for example, used water to lubricate the path of sleds employed to transport extremely heavy objects. The first scientific studies of frict...

BI-PHASIC BIOMATERIAL AND ARTICULAR CARTILAGE E.Northwood , R.Kowalski and J.Fisher * Institute of Medical and Biological Engineering, University of Leeds, Leeds, UK. +** DePuy CMW, Cornford Rd, Blackpool, England Email: [email protected] INTRODUCTION Natural articular cartilage has a unique biphasic lubrication regime [1]. Internal interstitial fluid pressure [2, 3] leads to low levels of fr...

Nanotube/matrix interfacial friction and sliding in composites with an amorphous carbon matrix L. Li, J.B. Niu, Z.H. Xia,a,⇑ Y.Q. Yang and J.Y. Liang Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203, USA School of Materials, Northwestern Polytechnic University, Xi’an, People’s Republic of China Department of Mechanical Engineering, Worcester Polytechn...

To model cohesionless granular flow using continuum theory, the usual approach is to assume the cohesionless Coulomb-Mohr yield condition. However, this yield condition assumes that the angle of internal friction is constant, when according to experimental evidence for most powders the angle of internal friction is not constant along the yield locus, but decreases for decreasing normal stress c...