Composite/metal stack materials, which have excellent mechanical properties, are wideyl used in aerospace industry. However, their machining operation is challenging due to two different material. In this study materials consisting of CFRP and Al 7075-T6 were drilled with drilling parematers investigate delamination defect, thrust force, inner surface roughness hole wear the cutting tool. Cutti...

Rock strength is an essential and effective property in the rock drilling, excavation, cost evaluation. This work aims to examine a practical approach evaluate geomechanical properties that control drillability, such as uniaxial compressive (UCS) by utilising some petrophysical parameters (porosity bulk density) elastic (Young’s modulus, slowness). To achieve this aim, study was conducted on Ju...

In this paper, the piston rebound common to both the Schmidt Impact Hammer and downhole hammer drills has been analyzed and calculated by means of stress wave theory and the energy conservation law. A quantitative relationship between the amount of rebound of the piston and the impact resistance index, or hardness of the rock, has been established. Those analytical results will not only be of b...

Scientific selection of drill bits during drilling is a key technology to achieve high-speed drilling and reduce drilling costs. Based on the analysis of bit’s working principles and its applicable conditions and in accordance with the well conditions of ultra-deep wells in Y area of Tarim Oilfield, this study has conducted mathematical statistics on a large number of actual drilling practices ...