Recent environmental concern has been raised about the development of biocomposites because their low cost, eco-friendliness, and biodegradability. Machining polymeric composite is inevitable during assembly structural components. In view creating holes in composites, drilling necessary it essential to carry out research find optimal machining parameters. The experimental assessment prediction ...

in this paper, by numerical simulation of gas flow, effects of divergence angles on the amplification factor, side force and thrust vector magnitude of a moveable nozzle with supersonic split line have been investigated. the study is conducted for constant exit to throat area ratio and the location of the split line is also constant. the finite volume method with second order upwind scheme for ...

Conventional drilling has been widely used for making holes in structural materials. However, drawbacks like high cutting forces, poor surface finish, temperatures, excessive tool wear, and undesirable burr formation while magnesium alloys have necessitated the development of alternative hole-making methods. Lately, helical milling process attracted interest facilitating assembly applications. ...

The distinguishing characteristics of carbon fibre reinforced laminates, like low weight, high strength or stiffness, had resulted in the increase of their use during the last decades. Although parts are normally produced to “near-net” shape, machining operations like drilling are still needed. In result of composites non-homogeneity, this operation can lead to delamination, considered the most...

CFRP/Al laminate material is widely used in aerospace due to its advantages of light weight and high machinability. For assembling, crowded assembly holes need be drilled for products. However, the damages burr, delamination, tearing appear frequently drilling without precise guidance by mechanical response model. In order reduce machining damages, this paper, a high-reliability model establish...

With the rapid growth of oil and gas storage, transportation, pipeline industries, it is necessary to improve construction process pipelines. By combining technical advantages horizontal directional drilling pipe jacking construction, direct laying method suitable for crossing in different strata gas, water conservancy hydropower, municipal industries due its less land, high speed, reversibilit...

The study of rotary steering drilling technology is currently one of the hot topics in the drilling engineering field. It requires accurate well trajectory control instructions when rotary steerable tools are applied to achieve the well trajectory control goal. A drilling trajectory prediction model will benefit this progress. According to the continuous beam theory, a mechanical model of push-...

BACKGROUND The aim of the present study was to evaluate the relationship between insertion torque and stability of miniscrews in terms of resistance against dislocation, then comparing a self-tapping screw with a self-drilling one. METHODS Insertion torque was measured during placement of 30 self-drilling and 31 self-tapping stainless steel miniscrews (Leone SpA, Sesto Fiorentino, Italy) in s...

The automation of machining processes requires highly accurate process monitoring. However, the use of additional sensors leads to a significant increase in the cost and reduces the stiffness and reliability of mechanical systems. Hence, we propose a system called the cutting force and torque observer, which uses a sensor-less and real-time cutting force estimation methodology based on the dist...

Due to temperature increase during bone drilling, bone necrosis is likely to occur. To minimize bone tissue damage during drilling, a detailed in vitro experimental study by using fresh calf cortical bones has been performed with various combined drilling parameters, such as: drilling environment, drill diameter, drill speed, drill force, feed-rate and drill coating. Bone temperatures at the dr...