A rupture model with varying rupture front expansion velocity for the March 11, 2011, Tohoku-Oki earthquake was obtained by the joint inversion of high-rate Global Positioning System (GPS) data and ocean bottom GPS/acoustic (OB-GPS) data. The inverted rupture velocity with a complex distribution gradually increases near the hypocenter and shows rapid rupture expansion at the shallowest part of ...

The fundamental processes of tribology related to friction, wear, and adhesion [1–3] are still not well understood [4,5]. When a single asperity touches and slides on a surface, complex phenomena such as local rearrangements of atoms, permanent change of the surface structure [6], and more macroscopic phenomena such as dislocation motion or microstructural changes can occur. As the interface is...

15 In order to reproduce slow earthquakes with short duration such as very low 16 frequency events (VLFs) migrating along the trench direction as swarms, we apply a 17 3-D subduction plate boundary model based on the slowness law of rate-and 18 2 state-dependent friction, introducing close-set numerous small asperities 1 (rate-weakening regions) at a depth of 30 km under high pore pressure cond...

A model has been developed to predict crack opening and closing behavior for propagating fatigue cracks which undergo significant sliding displacements at crack flanks. Crack surfaces were described statistically by assuming a random distribution of asperity heights and a mean density of asperities and asperity radii. The propagating crack was subdivided into strips, and each strip was treated ...

Cold atmospheric plasma (CAP) treatment was used on ultra-high molecular weight polyethylene (UHMWPE), a common articulating counter material employed in hip and knee replacements. UHMWPE is a biocompatible polymer with low friction coefficient, yet does not have robust wear characteristics. CAP effectively cross-links the polymer chains of the UHMWPE improving wear performance (Perni et al., A...

Proper methods and models for mechanical analysis of rough surface can improve the theory contact. When topography parameters two surfaces are similar, contact should be considered shoulder-shoulder rather than top-top. Based on fractal characteristics, geometric model asperity mechanics established, deformation asperity, real area load sealing discussed. The effects pressure p (fractal dimensi...

In chemical mechanical polishing (CMP), a rigid wafer is forced on a rough elastomeric polishing pad, while a slurry containing abrasive particles flows through the interface. One of the important factors that influence the material removal rate in CMP is the magnitude of contact force transmitted to the abrasive particles trapped at the contact interface. The total push-down force is distribut...

This paper reviews three important aspects of tribology (adhesion, lubrication and wear) on the atomic scale with a focus on our work on aluminum surfaces. Adhesion is critical to the success of many applications but there is no simple analytical model available to predict adhesion between different materials, so we discuss the use of electronic structure methods to investigate adhesion between...