Composite materials are widely employed in the naval, aerospace and transportation industries owing to the combination of being lightweight and having a high modulus of elasticity, strength and stiffness. Drilling is an operation generally used in composite materials to assemble the final product. Damages such as the burr at the drill entrance and exit, geometric deviations and delamination are...

Deep hole drilling methods are used for drilling holes with a high length-to-diameter ratio, good surface finish and straightness. Due to the slender tool-boring bar combination needed for producing holes with a high length-to-diameter ratio, the process is susceptible to dynamic disturbances. These disturbances can be classified as chatter vibration or spiralling. The work presented in this pa...

This paper focuses on the effect of the drill geometry on the drilling of woven Carbon Fiber Reinforced Polymer composite (CFRPs). Although different geometrical effects can be considered in drilling CFRPs, the present work focuses on the influence of point angle and wear because they are the important factors influencing hole quality and machining forces. Surface quality was evaluated in terms...

The use of blasting cost (BC) prediction to achieve optimal fragmentation is necessary in order to control the adverse consequences of blasting such as fly rock, ground vibration, and air blast in open-pit mines. In this research work, BC is predicted through collecting 146 blasting data from six limestone mines in Iran using the artificial neural networks (ANNs), gene expression programming (G...

This paper proposes a novel smart surgical navigation system for intramedullary nailing in orthopedic surgery. Using a handle-integrated laser guidance module, the system can target a drill insertion point onto skin, indicating an accurate target position to perpendicularly access an invisible distal hole. The proposed handle-integration-based fixation of the laser guidance module precisely def...

Bone fracture due to an accident, aging or diseases is a feature of everyday life. One of the principal methods of repair and reconstruction of such a fracture is based on drilling the bone and fixing its separate parts together using screws, wires and plates. Morphology of the drilled hole surface and fixative components such as screws, pins and hooks influences strength of the bonds between t...

[1] Thermal records from boreholes in young oceanic crust, in which water is flowing up or down, are used to assess formation and borehole flow properties using three analytic equations that describe the transient thermal and barometric influence of downhole or uphole flow. We link these calculations with an iterative model and apply Markov chain Monte Carlo (MCMC) analysis to quantify ranges o...

In directional drilling, the most important thing that leads to pulling out the drill string is end of mud motor working life. Considering the working conditions of down hole mud motors; increasing the mechanical properties of their stator’s elastomer is crucial. Some attempts were done to increase the motor performance through geometrical changes but lack of material improvement is significant...

The rheological and filtration properties of drilling mud under down-hole conditions may be very different from those measured at ambient pressures and temperatures at the surface. This paper presents the results of an experimental investigation into the temperature and salinity and pH effects on drilling mud rheological and filtration properties. Results are given from tests on water base mud ...