The lack of continuity conditions of the rock materials presents a serious challenge for the continuum mechanics approach, hindering the effective use of the well-established methods such as the finite element method and the boundary element methods. In the presented paper a discrete technique based on molecular dynamics approach is used for computer constructing of polycrystal materials. On th...

The frictional resistance on a fault during slip controls earthquake dynamics. Friction dissipates heat during an earthquake; therefore, the fault temperature after an earthquake provides insight into the level of friction. The Japan Trench Fast Drilling Project (Integrated Ocean Drilling Program Expedition 343 and 343T) installed a borehole temperature observatory 16 months after the March 201...

The article describes the dynamics of drill bits, drilling modes, distribution resistance forces when with bits. theory a well arbitrary shape, possible shapes contacting figures at bottom hole and type bit operating in rotation pair mode are considered. This has properties double center rotation, which results attrition drilling. At same time, during drilling, load on will be located throughou...

For the past three decades the quantity of petroleum (both oil and oil plus gas) found per foot of drilling effort in the United States for any given year can be expressed as a secular decrease of about 2 percent per year combined with an inverse function of drilling effort for that year. Extrapolation of energy costs and gains from petroleum drilling and extraction indicates that drilling for ...

this investigation presents the effect of various parameters on foam stability and its rheological properties. the underlying idea of this experiment is generating of drilling foam with uniform bubbles. the main problem of foam using is controlling its stability during field application. the most important parameters which cause instability in foam are gravity drainage, gas diffusion and bubble...

Abstract— Due to the superior physical and mechanical properties Glass fiber-reinforced (GFRP) composite materials are very attractive for applications like aerospace and air craft structural components. This results a large number of research papers on machining of these composite laminates. Out of all the machining operations, most commonly used operation is drilling. However, drilling operat...

Because neurosurgery and orthopedic surgery often require the drilling of bones, this paper attempts to solve the problem of bone drilling. The goal is to realize a control system, which is able to drill with a contact drilling force and can automatically stop drilling at the moment of breaking through. In particular, both the de drilling mntor control and the feed rate control are driven by fo...

Bone drilling is widely used in orthopaedics and surgery; it is a technically demanding surgical procedure. Recent technological improvements in this area are focused on efforts to reduce forces in bone drilling. This study focuses on forces and a torque required for conventional and ultrasonically-assisted tool penetration into fresh bovine cortical bone. Drilling tests were performed with two...