We provide a brief overview of the Discrete Element Method (DEM) for modeling large frictional contact problems in granular flow dynamics and quasi-static geomechanics applications. In terms of contact, DEM can be divided into two approaches: the Constraint Method (CM) or rigid-body approach, and the Penalty Method (PM) or soft-body approach. We give a detailed presentation of a DEM-PM contact ...

This paper presents the modified design of a bidirectional electrothermal chevron beam microtweezer proposed by J. K. Luo [1]. The original design has been modified to include inward in-plane motion. Thus, the modified design is capable of bidirectional motion. The structures are designed and simulated using COMSOL Multiphysics 4.2a. The bidirectional chevron beam microtweezer shows an in-plane...

The characteristics of triple flames in a hydrogen–air mixing layer are studied using direct numerical simulation with detailed chemistry. Triple flames are initiated by imposing a temperature ignition source in the center of a scalar mixing layer of nonuniform thickness, thereby forming a pair of freely propagating triple flames. Two different fuel streams are studied: pure hydrogen and hydrog...

Direct displacement based design (DDBD) is a conceptual framework that directly design a structure to achieve an expected performance level under specified seismic intensity. In this study, two important issues relevant to torsional response of mass eccentric 8-story RC building designed with DDBD approach are investigated. These issues are including the effects of unbalanced mass distribution ...

Influence of initial surface topography on tribofilm formation in ZDDP lubricated contact was analysed. A small displacement fretting tests with sinusoidal motion were carried out in classical sphere/plane configuration. A range of surfaces with different initial roughness were prepared by milling and grinding processes. Tests were carried out using variable displacement method where amplitude ...

Aiming at the inherent problems of non-direct-drive injectors, such as long oil circuits and a difficult precise control needle stroke, based on structure direct-drive injector combined with demand for drive truck diesel injector, this study designs fabricates giant magnetostrictive actuator injectors. A simplified model is established, which mainly simplifies magnetization to facilitate subseq...

The purpose of this study was to evaluate the degree and amount of movement of the abutment tooth and denture base influenced by the direct retainer of distal extension removable partial denture and the location of functional loading, then to suggest direct retainer design with minimal adverse effect and with optimum functional loading location for residual tissue. The displacement of the abutm...