A hybrid slip model combined an Asperity model and k model for predicting near-field strong ground motion is proposed in this paper. Firstly, the asperity model charactering lower wave number of slip distribution is estimated based on works of Wang (2004), Wang and Tao (2004a, b). Secondly, k square slip model charactering higher wave number of slip distribution was determined based on research...

This paper presents an analysis of the interaction energy and various forces between two surfaces, and the microscopic study of friction. Atomic-scale simulations of dry sliding friction and boundary lubrication are based on the classical molecular dynamics (CMD) calculations using realistic empirical potentials. The dry sliding of a single metal asperity on an incommensurate substrate surface ...

A strength profile across the NE Japan interplate megathrust was constructed in the source region of the 2011 Tohoku-oki earthquake (Mw9.0) using friction, fracturing, and ductile flow data of the oceanic crustal materials obtained from laboratory experiments. The depth-dependent changes in pressure, temperature, and pore fluid pressure were incorporated into a model. The large tsunamigenic sli...

We treat a fault as an array of asperities with a prescribed statistical distribution of strengths. When an asperity fails, the stress on the failed asperity is transferred to one or more adjacent asperities. For a linear array the stress is transferred to a single adjacent asperity and for a two-dimensional array to three adjacent asperities. Using a renormalization group (RG) method, we inves...

Study of contact and friction at multiple length scales is necessary for the effective design and analysis of surfaces in sliding microand nano-electromechanical systems (MEMS/NEMS). As loading forces decrease in such applications, the size of the asperity contacts tends to decrease into the nano scale regime. Also with the increase in surface area to volume ratio in such systems, the surface f...

A detailed model of the role of asperities in crack closure has been initiated in Part 1 of this article. Crack opening stress is defined as the far-field stress required to overcome the asperity-induced contact stresses along the crack. In this Part 2, the magnitude of crack opening stress is established as a function of roughness (s0); asperity density (N); maximum stress level (Smax/Sy); sha...

The influence of the boundary layer properties on the heat transport in turbulent thermal convection is experimentally investigated in a cell with a rough bottom plate. It is shown that the standard 2/7 exponent of the convective heat flow dependence on the Rayleigh number, usually observed in cell with smooth boundaries, increases if the roughness has power law distributed asperity heights and...

the influence of surface roughness magnitude and direction on dry static friction coefficient between two similar steel samples has been studied through an experiment. a testing apparatus has been designed and fabricated to measure the friction coefficient for a few forms of surface asperity. according to the results of the experiments, dry friction coefficient is affected by both magnitude and...

The 1999 Chi-Chi earthquake (MW 7.6) (20 September 1999, 17:47:15.9 UTC) (located at 23.853 N, 120.816 E, and depth of 7.5 km) inflicted severe regional scale damage to Taiwan. The strong-motion wavefield was captured by a dense network of stations (with average station spacing of 5 km), which represents the most complete strong-motion dataset to date to use to study the kinematic source proces...

We predict a strongest size for the contact strength when asperity radii of curvature decrease below 10 nm. The reason for such strongest size is found to be correlated with the competition between the dislocation plasticity and surface diffusional plasticity. The essential role of temperature is calculated and illustrated in a comprehensive asperity size-strength-temperature map taking into ac...