Drilling Process Parameters Research Articles

Optimization of stir casting and drilling process parameters of hybrid composites

AA2219 alloy is widely used in aerospace and automobile applications, wherein the properties can be enhanced with 15% wt. of B4C reinforcement particles. Assembly task in aerospace application requires drilling millions of holes, and it is often challenging to obtain good-quality drilled holes due to the presence of hard B4C particle reinforcements. The self-lubricating capability of molybdenum disulfide (MoS2) and Graphene (Gr) materials was used as secondary reinforcements to improve the drilled hole quality characteristics. The stir-casting route fabricates the hybrid composites (AA2219 alloy/B4C/Gr/MoS2). The hardness and wear resistance properties of hybrid composites are affected by the influencing process variables such as percent reinforcement of Gr and MoS2, stirring speed, and pouring temperature. Taguchi L9 matrix is used for experimentation and performs statistical analysis. All stir-casting variables are found to make significant contributions toward hardness and wear resistance. The limitation of the Taguchi method to solve multiple objective optimizations is solved by applying Data Envelopment Analysis Ranking (DEAR) method. A DEAR method determined optimal conditions (Gr and MoS2: 1.5 wt%, stir speed: 400 rpm, and pouring temperature: 760 °C) resulted in a reduced wear rate of 1.65 × 10−3 mm3/min and 128 HV hardness in hybrid composites. The hybrid composites were prepared for the determined optimal stir casting conditions. Drilling experiments were carried out to analyze the variables such as feed rate (FR), drilling speed (DS), and drill tool material (DM): high-speed steel: HSS, carbide: C, and coated carbide: CC that affect the hybrid composite hole quality characteristics such as burr height: BH, material removal rate: MRR, and thrust force: TF. A DEAR method determined optimal drilling conditions (FR: 0.25 mm/rev; DS: 20 m/min; DM: coated carbide drill tool) resulted in 645 mm3/min of MRR, 2.95 kN for TF, and 0.16 mm for BH, respectively. The self-lubricating capability of Gr and MoS2 reinforcement particles in hybrid composites ensures excellent composite properties and drilled-hole quality characteristics. Taguchi and DEAR methods employ simple mathematical steps which can be used by novice industry personnel to perform optimization for other output characteristics.

Calculation method of the build-up rate of the internal push point-the-bit rotary steering tool

The internal push point-the-bit rotary steering tool is a new type of dynamic point-the-bit rotary steerable system. This paper comprehensively uses the mechanical and trajectory method to calculate the build-up rate of the tool to evaluate its build-up ability and realize accurate control of the wellbore trajectory during the directional drilling process. The influence of tool structure, wellbore geometric parameters, drilling process parameters, bit-cutting anisotropy, and formation characteristics on the build-up ability are considered. The tool deflection force, the structural lateral force on the bit, and the formation deflection force were calculated respectively, and the calculation model for the build-up rate of the internal push point-the-bit rotary steering tool is established according to the relationship between force and cutting displacement. In order to study the variation of the build-up rate of the tool in different well slope sections under the conditions of fixed bottom hole assembly and formation parameters, the build-up rate simulation calculation was carried out. The calculation results show that the maximum build-up rate of the tool under stable and controlled conditions increases with the increase of the well inclination, which means the internal push point-the-bit rotary steering tool is suitable for extended reach wells and horizontal wells. The research results provide a theoretical basis for the design of bottom hole assembly and the optimization of drilling process parameters when using the internal push point-the-bit rotary steering tool for directional drilling.

Optimization of drilling process parameters of sisal/cork-reinforced epoxy biosandwich structure by multi-objective RSM and hybrid ANN-GA models

Optimization of drilling process parameters of sisal/cork-reinforced epoxy biosandwich structure by multi-objective RSM and hybrid ANN-GA models

Failure analysis of formed internal threads in flow drilled bores of AlSi10Mg cast profiles

Manufacturing the internal thread in lightweight components using chipless flow drilling and internal thread forming processes can reduce material and time consumption. Furthermore, using these methods imposes a further work-hardening into the subsurface of the formed thread profiles and consequently improves the thread strength. While the required core hole diameter for conventional (cut) tapping depends on the thread dimension, this diameter depends either on the material properties such as ductility for the thread forming process (form tapping). This work investigates the effect of the used process parameters in flow drilling (friction drill speeds and diameter) on the quality of the drilled bores and the formed threads. A total metallographic analysis was performed according to the formed regions by the flow drilling process and was correlated to the measured hardness profile conducted along the bore thickness. The CT scan was chosen to measure the dimension deviation of the manufactured bores and their effects on the formed threads. Correlating the deviation to the quasi-static and dynamic strengths declared that decreasing the tool diameter by 0.1 mm decreased the inner volume of the friction drilled bore, which enhanced the geometry of the formed thread and increased the percentage of the thread engagement and the strengths accordingly. Although the friction drilling with an adaptive speed reduced the oversizing of the created bore in comparison to the flow-drilled bores with a constant speed, measuring the volume of the formed threads into mentioned bores indicated an opposite trend. While the formed M6 threads into the flow drilled bores with constant speed showed a better strength by subjecting to a quasi-static load, manufactured threads with an adaptive speed indicated a higher dynamic strength from the load increase fatigue test. S-N curves declared that the adapted flow drilling speed led to higher dynamic strength of the formed thread subjecting to the fatigue tests in the HCF (High Cycle Fatigue) range. The measured results from NDT monitoring by the ACPD method were correlated to plastic strain up to failure. The in-situ quasi-fatigue test in the CT scan clarified the fatigue fracture according to cyclic softening and hardening, or possible crack initiation and propagation in thread profiles during the fatigue test.

Drilling process parameter optimization of natural fibre reinforced polymer matrix composites

Machining of polymer matrix composites is a complex phenomenon owing to anisotropic behavior of these materials. Optimization of drilling process parameters were aimed in this work with determination of delamination factor. Polymer matrix composites were fabricated by mixing of matrix and reinforcement under varying ratios of weight and different layers of reinforcement for characterization. Plies were arranged as 8 jute, 6 jute and 2 silk, 4 jute and 4 silk, 2 jute and 6 silk and 8 silk plies respectively. Composite fabrication was followed by drilling of composites with different bit sizes and spindle speeds taking varying bit sizes of 3.20, 4.20, 4.75, 5.56 mm and the spindle speeds of 720, 960, 1200, 1440 rpm respectively. Finally, optimization in Minitab using the TAGUCHI were analyzed and optimized data for minimum delamination determined for different polymer combinations. The hybridized laminates with both jute and silk combinations are observed to have reduced delamination factor here as compared to all jute or all silk ply laminates which can be an important criterion in damage minimization on account of delamination due to drilling. This study presents analysis which can help in improved machining of polymer matrix composites with minimum of wastage and enhance scope of application of these materials in modern technological advancements involving assemblies and thereby requiring drilled holes.

Experimental investigations on drilling of hybrid composites using different drill bit geometries

The incorporation of different types of fibres into a single matrix has led to the development of hybrid composites. Hybrid composites are considered to be materials of greater potential for most of the engineering applications. Drilling is a cutting process that uses a drill bit to cut a hole of circular cross-section in metals, alloys and composites. The twist drill geometry controls the quality of the hole along with the drilling process parameters. Different drill bit geometries were designed and manufactured. Taguchi based experiments were conducted on hybrid composites with different drill bits. This paper discusses the influence of the different drill bit geometry (Helix angle, Lip angle and Point angle) and the drilling process parameters on the quality of the drilled hole. It is found that better hole quality can be achieved by designing a drill bit with optimum helix angle, point angle and drilling conditions.

Optimized Process Parameters for Low-Carbon and Low-Cost Flange Drilling

Optimized Process Parameters for Low-Carbon and Low-Cost Flange Drilling

Optimising the drilling process parameters of Kevlar-epoxy composite material using the experimental design-based goal programming approach

Optimising the drilling process parameters of Kevlar-epoxy composite material using the experimental design-based goal programming approach

Multi-objective Optimization Method of CFRP Drilling Process Parameters for Power and Drilling Quality

Multi-objective Optimization Method of CFRP Drilling Process Parameters for Power and Drilling Quality

Machining Performance Analysis of Rotary Ultrasonic-Assisted Drilling of SiCf/SiC Composites

An SiCf/SiC composite has the following excellent properties: high strength, low specific gravity, and high temperature resistance, which has great prospects in the combustion chamber of rockets or aero engines. Hole-making in SiCf/SiC parts is an important processing method. Generally, water-based or oil-based coolants are avoided, so dry drilling is the primary hole-making approach for SiCf/SiC. However, the abrasion resistance and high hardness of SiCf/SiC often lead to fast tool wear as well as serious damage to the fiber and matrix during dry drilling. This study proposes an innovative strategy for hole-making in SiCf/SiC parts—rotary ultrasonic-assisted drilling (RUAD) using an orderly arranged brazed diamond core drill. The influence of tool life and wear on drilling accuracy is analyzed. Additionally, the impacts of the process parameters of conventional drilling (CD) and RUAD on drilling force, torque, the surface roughness of the hole wall, and the exit tearing factor are investigated. The results show that the orderly arranged brazed diamond core drill exhibits longer tool life and higher accuracy in hole-making. Meanwhile, compared with CD, RUAD with the proposed core drill effectively improves the drilling quality and efficiency, and reduces the force and torque of drilling. The range of process parameters for dry drilling is broadened.

Nonlinear dynamic analysis of liquid-solid coupling and rubbing on drill string

Natural deposit of natural gas hydrate (NGH) exists in the colder regions on the earth, which is an unconventional energy and has great potential. About 97% of the NGH is located in the offshore and only 3% is located on the land. Due to its sensitivity to the external environment and easy decomposition, it is necessary to suppress the external environment changes caused by the complex vibration of the drill string during its exploitation. In this paper, the fluid-solid coupling nonlinear vibration of drill string is studied. The nonlinear dynamic model of drill string with drilling fluid is established. The relationship between variable parameters of drill string and complex dynamics of drill string is analyzed. Furthermore, the bifurcation diagram is given. The results have certain significance for discussing the non-linear dynamic mechanism of drill string under complex conditions and reasonably selecting the drilling process parameters of NGH.

Theoretical study on fatigue damage of sonic standing wave resonant drill-string

To achieve high-speed and undisturbed core drilling, the standing wave vibration of the drill string in a sonic drill is excited by a high-frequency inertial vibrator; the resulting high alternating stress cycle in the drill string can easily cause fatigue damage. In order to minimize the fatigue failure of drill-string at the stage of its design, it is necessary to assess the fatigue damage caused by alternating stress to guide engineering practice. In this paper, based on one-dimensional wave theory, we analyse the standing wave vibration in a drill-string excited by a sonic vibrator, and theoretically prove that the dynamic resonant stress of a drill-string is the key factor influencing the fatigue damage. By using the Palmgren–Miner fatigue damage rule, we establish a theoretical formula for the cumulative fatigue damage of a variable-length standing wave vibration drill string and reveal the fatigue damage mechanism of the variable-length resonant drill string. Furthermore, the effects of sonic drill systems and process parameters on the damage are quantified. It was found that by an appropriate choice of a drill-pipe length, the fatigue damage can be reduced whilst the axial stress concentration factor (aSCF) kσ on threaded connections can significantly increase it. At the fundamental frequency of the resonant sonic drilling, the maximum fatigue damage point, xf, is located approximately la/2 above the drill bit, not exceeding the theoretical sonic standing wave starting length, la, and unrelated to the hole depth. This study promotes the theoretical understanding and exploration of variable-length standing wave oscillators.

Parametric Optimization In Drilling Process Parameters For Machining Of Glass Fibre Reinforced Composites Using Grey Relational Grade Analysis

The aim of the research is to optimize the drilling process parameters while drilling of glass fi bre reinforced composites using solid carbide drill by integrating response surface methodology and Taguchi technique. Drilling process parameters includes cutting speed, Feed rate and point angle with three levels. The responses measured against these drilling parameters are; material removal rate, surface roughness, oversize and delamination factor. The ANOVA analysis is carried out for the responses and the regression equations are developed and checked for its adequacy. The R-squared value for material removal rate is found to be 99.40%, for surface roughness is found to be 96.81% , for over size is found to be 98.2% and for delamination factor is found to be 96.46% and these values are acceptable. Also Taguchi grey relational grade analysis is carried and the grey relational coeffi cients are determined and they are ranked. The optimal parameter is fi nally determined using the grey relational analysis and the experiments are validated.

The Development of a Digital Twin Framework for an Industrial Robotic Drilling Process.

A digital twin is a digital representation of a physical entity that is updated in real-time by transfer of data between physical and digital (virtual) entities. In this manuscript we aim to introduce a digital twin framework for robotic drilling. Initially, a generic reference model is proposed to highlight elements of the digital twin relevant to robotic drilling. Then, a precise reference digital twin architecture model is developed, based on available standards and technologies. Finally, real-time visualisation of drilling process parameters is demonstrated as an initial step towards implementing a digital twin of a robotic drilling process.

DRILLING PARAMETRIC ANALYSIS OF PERFORATED COPPER FOIL ON HEMP/ SISAL FIBER COMPOSITE USING SEQUENTIAL ANN

Innovation in developing optimized process parameters is vital to meet industrial demand in composite applications. Especially in the fiber composite drilling process, unexpected dimensional errors cause failure due to the anisotropic nature of cellulosic fibers and heterogeneity in reinforcement. A sequential artificial neural network (SANN) technique has been required for composite drilling to predict a wide range of operating conditions and analyze the dimensional imperfections. The work fabricates three different sisal/ copper foil/ hemp (SCH) hybrid composites with varying perforated copper foil pitches (10/20/30[Formula: see text]mm) designs. The drilling experiments were designed using a central composite design. The effect of experimental/ SANN input parameters [spindle speed, drill point angle (DPA) (92°, 112°, and 132°), composite type, feed rate] and output responses (thrust force, torque, and roundness) were analyzed. The SANN model was trained through the experimental data and verified with a test set of experiments. Finally, the proposed SANN model was used to predict the drilling responses at a lower limit to the higher operating range for 70 validation experiments. The interaction responses were analyzed using the response surface methodology technique between the drilling (Input/ Output) process parameters. The experimental results inferred that the SCH-3 type with a higher pitch between the perforations shows minor roundness error. A drill bit with higher DPA (132°) induces more delamination effects in the laminates. The validation experiments revealed that the predicted ANN data correlated with the experimental data with less than 2% mean absolute error.

Application of geomechanics in the construction of horizontal wells at the fields of Embamunaigas JSC

Horizontal drilling is currently being actively developed in the near and far abroad to increase oil production, and Embamunaigas JSC is a prime example of this type of drilling in Kazakhstan. At the same time, horizontal drilling is a fairly complex and costly process, just like the construction of deep exploration wells, which requires a comprehensive approach to planning and execution of work.
 Geomechanical modelling plays a crucial role in selecting process parameters for drilling, determining optimum well design and other characteristics required to ensure wellbore integrity and overall well construction success.
 The mechanical properties model takes into account rock strength characteristics, horizontal stress directions of the geological environment and many other aspects that help make drilling safer, reduce the risk of complications and maintain borehole integrity.
 This study describes the process of creating geomechanical models for the construction of complex horizontal wells in the fields of Embamunaigas JSC based on the geomechanical core studies carried out at the S. Nurzhanov field and an analysis of the hydraulic fracturing database for the fields of Embamunaigas JSC. As a result, a safe drilling mud density range (safe drilling window) was determined and recommendations were given for the optimisation of drilling parameters and well design.

Numerical Simulations and Experiments on Single-Tooth Rock-Breaking

The rock-breaking efficiency of a drilling tool directly affects the production costs and progress of foundation construction. It is essential to understand the mechanism of mechanical rock-breaking to improve rock-breaking efficiency. In this study, dynamic rock-breaking simulation research was carried out on a drill bit and was based on the LS-DYNA simulation platform. Additionally, the influence of the rotational speed of the spindle and the feed rate on the force of the drill bit in the rock-breaking process was obtained. The influence of the rotational speed of the spindle and the feed rate on drill vibration was also analyzed. The content of the presented theoretical and simulation research was verified through experiments. The following conclusions were drawn: first, the reaction force that rock has on the drill bit presents a law according to different rock types and drilling process parameters. With the increase in rotational speed, the axial reaction force decreases. With the increase in the feed rate, the axial reaction force increases. The effect of rock type on axial reaction force is nonlinear. Second, the influence of the spindle rotational speed and feed rate on the vibration of the drill bit also presents a law during rock-breaking. When the feed amount is constant, the transverse vibration slows down, and the axial vibration intensifies as the rotational speed increases. When the rotational speed is constant, as the feed increases, the transverse vibration slows down and the axial vibration intensifies. The research results provide a theoretical basis for selecting drilling process parameters and for improving rock-breaking efficiency.

A MULTI-OBJECTIVE GREY RELATIONAL APPROACH AND REGRESSION ANALYSIS ON OPTIMIZATION OF DRILLING PROCESS PARAMETERS FOR GLARE FIBER METAL LAMINATES

Fiber metal laminates (FML) are used in outer covering of the fuselage skin structure. The thrust force and the torque generated during drilling process affect the quality of the holes on the structure. The magnitude of cutting forces is controlled by optimizing the drilling process parameters. In this study, the influence of drilling parameters such as spindle speed, feed rate and the weight percentage of layered double hydroxides (LDH) in the binder epoxy on the thrust force and torque during drilling operation was studied. The experiments were designed based on Taguchi’s L9 orthogonal array. The Gray Relational Analysis was used as multi-objective optimization tool for finding the optimal combination of process parameters. The spindle speed was identified as the most influencing process parameter to affect the drill quality in the FMLs. SEM images taken on the drilled specimens for the best and worst input parameter settings were compared and discussed. The regression models were generated to predict the output response values within the range of actual experiments.

Dimension-based failure analysis of formed internal threads in AlSi10Mg cast profiles using coupled DT/NDT testing methods

The production of detachable joints in lightweight components using friction drilling and internal thread forming processes could be considered as a lightweight design strategy, which can reduce material and time consumption and enhance the thread strength by imposing a further work-hardening into the subsurface of the formed threads. Pre-study indicated that oversizing the friction drilled bores as a pilot bore can hinder the complete deformation of the thread profiles during the thread forming process. This work investigates the effect of process parameters in the friction drilling process (friction drill speeds and diameter) on the quality of the drilled bores and following formed threads. Computed tomography was chosen to measure the dimension deviation of manufactured bores and threads. Comparing the deviation with the measured static and dynamic strengths declared that increasing the tool diameter by 0.1 mm increased the inner volume of the friction drilled bore, which led to an incomplete deformation of the thread profiles and decreased static and cyclic strength accordingly. Although the friction drilling with an adaptive speed reduced the oversizing of the created bore in comparison to the friction drilled bores with a constant speed, measuring the volume of the formed threads into mentioned bores indicated an opposite trend. While the formed M6-threads into the friction drilled bores with constant speed showed a better strength by subjecting to a quasi-static load, manufactured threads with an adaptive speed indicated a higher dynamic strength. The fatigue tests were monitored through NDT methods by measuring the change in deformation-induced temperature and ACPD potential. The measured results were correlated to plastic strain up to failure corresponding to occurring softening, hardening, or possible crack initiation and propagation in thread profiles.

Multi-objective optimization of drilling process parameters in Al Si6 Cu3 via grey relational analysis and ANOVA

Multi-objective optimization of drilling process parameters in Al Si6 Cu3 via grey relational analysis and ANOVA