Mode Machining Research Articles

Phase shifting-based debris effect detection in USV-assisted AFM nanomachining

Atomic force microscopy (AFM) mechanical-based lithography attracts much attention in nanomanufacturing due to its advantages of low cost, high precision and high resolution. However, debris effects during mechanical lithography often lead to an unstable machining process and inaccurate results, which limits further applications of AFM-based lithography. There is a lack of a real-time debris detection approach, which is the prerequisite to eventually eliminating the influence of the debris, and of a method that can solve the above problems well. The ultrasonic vibration (USV)-assisted AFM has the ability to sense the machining depth in real time by detecting the phase shifting of cantilever. However, whether the pile-up of debris affect the phase response of cantilever is still lack of investigation. Therefore, we analyzed the mechanism of the debris effect on force control mode and investigated the relationship between phase shifting and pile-up of debris. Theoretical analysis and experimental results reveal that the pile-up of debris have negligible effect on phase shifting of cantilever. Therefore, the phase shifting-based method can detect the debris effect on machining depth in force control mode of AFM machining.

Investigation on Failure Strength of Bolted Joints Woven Fabric Reinforced Hybrid Composite

Understanding of composite bolted joint behaviour is vital since it has been widely used in application involving mechanically fastened joints. The advent of advanced technology had led to the use of hybrid composite to reduce the usage of non-environment friendly material such as synthetic fibre. This current study aims to investigate the effect of geometric parameters on the failure load of bolted joint hybrid composite laminate. Composite laminates were fabricated using hot press moulding compression method and they were cut according to the appropriate dimension with the width/diameter (W/D) and edge-distance/diameter (E/D) ratio of 3, 4, 5 and 6. The hole diameter of each composite laminate was fixed at 6 mm. Bolted joint tests were conducted in accordance to ASTM D5961 using the Universal Testing Machine and several failure modes were identified. The results concluded geometric parameters significantly affect both failure load and failure mode of hybrid composites. The increase in W/D and E/D ratio increase the load carrying capability of the laminate.

Экспериментальная оценка режимов размерной обработки углепластиков импульсным наносекундным излучением волоконного иттербиевого лазера

Экспериментальная оценка режимов размерной обработки углепластиков импульсным наносекундным излучением волоконного иттербиевого лазера

Experimental study of single cubic boron nitride grains in the ultrasound-assisted high-speed grinding

The kinematic characteristics, grinding force, surface quality of workpiece surface, and wear of abrasive particles were studied by theoretical analysis and experimental study on the single cubic boron nitride abrasive particles under ultrasonic-assisted high-speed grinding. Under the condition of the same grinding parameters, the motion characteristics and the grinding forces of the two machining modes of general grinding and ultrasonic-assisted grinding are compared and analyzed. Research shows that the ultrasonic vibration is applied in the common external circular grinding on grinding particle movement characteristics changed obviously, grinding particle trajectory of variable length, cutting groove width wider, thereby improving the grinding efficiency and the grinding removal rate; ultrasonic assisted under high speed grinding, the grinding force is higher than that of common grinding force is small, efficiency of grinding under ultrasonic processing mode is much higher than ordinary grinding, the surface quality of the workpiece has improved markedly.

Применение принципа обратной связи для решения уравнений трансформаторов и электрических машин

Anapproach is suggested according to which the primary winding resistance istakeninto account using the well-known feed back principle. The search procedure involves two stages. In the first stage, a voltage source is applied behind the resistance. Then, if flux linkages of the loops are taken as independent variables instead of currents, the order of the equation system to be solved is decreased by unity, a circumstance due to which both the search and the form of sought solutions become essentially simpler. Atthesecondstage, a mathematically rigorous correlation between the conditional and actual voltage across the terminals is found using atechnique known as the feed back principle, as a result of which the preliminarily found quantities are presented as functions of the actual voltage across the terminals. Examples demonstrating the validity and effectiveness of the proposed approach are given as applied to a number of problems concerned with studying steady-state and transient modes of electrical machines and transformers.

Research of the Hardware Architecture of the Geohazards Monitoring and Early Warning System Based on the Iot

For the need of improving the capacity of the geohazards monitoring, a professional monitoring system has been developed based on the Internet of things, WSN (Wireless Sensor Network) and network communication technology. The system consists of wireless sensing network, transmission network and data monitoring and analysis center. The WSN technology was used to organize network with displacement, tilt angle and rainfall in the wireless sensing network which could achieve perception and control all aspects of the monitoring area. The monitoring data can be transferred in two methods by the transmission network which was established based on the GSM and Beidou. The wireless sensing nodes can be controlled remotely by data monitoring and analysis center. For example, the acquisition interval can be modified remotely, the current data can be controlled to return immediately and sensing nodes can be controlled to entry into low power mode in order to save power, which means that Machine to Machine mode of geological disaster monitoring had been realized in the system.

Hybrid Transactional Replication: State-Machine and Deferred-Update Replication Combined

We propose Hybrid Transactional Replication (HTR), a novel replication scheme for highly dependable services. It combines two schemes: a transaction is executed either optimistically by only one service replica in the deferred update mode (DU), or deterministically by all replicas in the state machine mode (SM); the choice is made by an oracle. The DU mode allows for parallelism and thus takes advantage of multicore hardware. In contrast to DU, the SM mode guarantees abort-free execution, so it is suitable for irrevocable operations and transactions generating high contention. For expressiveness, transactions can be discarded or retried on demand. We formally prove that the higher flexibility of the scheme does not come at the cost of weaker guarantees for clients: HTR satisfies strong consistency guarantees akin to those provided by other popular transactional replication schemes such as Deferred Update Replication. We developed HTR-enabled Paxos STM, an object-based distributed transactional memory system, and evaluated it thoroughly under various workloads. We show the benefits of using a novel oracle, which relies on machine learning techniques for automatic adaptation to changing conditions. In our tests, the ML-based oracle provides up to 50% improvement in throughput when compared to the system running with DU-only or SM-only oracles. Our approach is inspired by a well known algorithm used in the context of the multi-armed bandit problem.

ОБЕСПЕЧЕНИЕ ТРЕБУЕМОЙ ШЕРОХОВАТОСТИ ПОВЕРХНОСТЕЙ ИЗДЕЛИЙ ИЗ МЕТАЛЛОПОЛИМЕРА НАПОЛНЕННОГО АЛЮМИНИЕМ ПРИ ОБРАБОТКЕ ШЛИФОВАНИЕМ

Currently, machine-building enterprises are increasingly using new composite materials for the production of parts, accessories and repair. One such material is a metallopolymeric composite structure with an aluminum filler. In general, it is an epoxy-dienoic filled with an aluminum matrix excipient. Owing to its flow properties in the uncured state, and hardness and heat resistance when cured, the material is increasingly used in the production. Previous studies have shown the use of metal-polymer material as the material forming the mold parts, as this significantly reduces the cost of equipment for molding plastics. Unlike steel machining modes metallopolymers insufficiently studied, because the material is new, and as yet only finds its field of application. However, in the manufacture of it forming tooling molds required to appoint such process steps and processing modes, which will provide the required dimensional accuracy and surface roughness detail. For a given parameter surface roughness of a metallopolymeric in the processing of grinding was found model of the surface roughness of the parameter rate table movement and the depth of cut.

The thermodynamic efficiency of ATP synthesis in oxidative phosphorylation

As the chief energy source of eukaryotic cells, it is important to determine the thermodynamic efficiency of ATP synthesis in oxidative phosphorylation (OX PHOS). Previous estimates of the thermodynamic efficiency of this vital process have ranged from Lehninger's original back-of-the-envelope calculation of 38% to the often quoted value of 55–60% in current textbooks of biochemistry, to high values of 90% from recent information theoretic considerations, and reports of realizations of close to ideal 100% efficiencies by single molecule experiments. Hence this problem has been reinvestigated from first principles. The overall thermodynamic efficiency of ATP synthesis in the mitochondrial energy transduction OX PHOS process has been found to lie between 40 and 41% from four different approaches based on a) estimation using structural and biochemical data, b) fundamental nonequilibrium thermodynamic analysis, c) novel insights arising from Nath's torsional mechanism of energy transduction and ATP synthesis, and d) the overall balance of cellular energetics. The torsional mechanism also offers an explanation for the observation of a thermodynamic efficiency approaching 100% in some experiments. Applications of the unique, molecular machine mode of functioning of F1FO-ATP synthase involving direct inter-conversion of chemical and mechanical energies in the design and fabrication of novel, man-made mechanochemical devices have been envisaged, and some new ways to exorcise Maxwell's demon have been proposed. It is hoped that analysis of the fundamental problem of energy transduction in OX PHOS from a fresh perspective will catalyze new avenues of research in this interdisciplinary field.

Real-time acquisition of machining task progress based on the power feature of workpiece machining

The real-time acquisition of machining task progress is one of the most important tasks of production management and is an essential aspect of manufacturing information. Targeted to the machining mode of mixed-category workpieces in job shops, a method for the acquisition of real-time machining task progress is proposed. The method is based on both the power feature of workpiece machining and the incremental learning Lagrangian support vector machine. First, the framework for this method is presented in a straightforward manner. Second, by analysing the characteristics of power change during the machining process, the power feature vector, which reflects the characteristics of workpiece machining, is designed for Lagrangian support vector machine. Then, based on the principle of incremental learning Lagrangian support vector machine, which can address the classification of mixed-category workpieces and the problem of an insufficient number of training samples for training the initial classifiers during the actual machining process, a detailed application of this method is constructed for workpiece classification and the acquisition of machining task progress. Finally, the effectiveness of this method is empirically tested by application to a case study.

A Hybrid of EEMD and LSSVM-PSO model for Tourist Demand Forecasting

In this research, hybrid model of Least Square Support Vector Machine (LSSVM) and Ensemble Empirical Mode Decomposition (EEMD) are presented to forecast tourism demand in Malaysia. Foremost, the original series of tourism arrivals data was separated using EEMD technique into residual and Intrinsic Mode Functions (IMFs) components. Next, both of IMFs and residual components were forecasted using Particle Swarm Optimization (LSSVM–PSO) method. In the end, the predicted result of IMFs and residual components from LSSVM–PSO method are sum together to produce the forecasted value for tourism arrivals in Malaysia. Empirical results showed that the presented model in this paper outperform individual forecasting model. The result indicated that LSSVM–PSO is a promising tool in time series forecasting by having the presence of non-stationary and non-linearity in the time series data.

Influence of pulse recurrence frequency on the accuracy of electrochemical machining of nickel, copper, and steel

The influence of pulse recurrence frequency on the accuracy of electrochemical machining of steel 08KP, nickel H1, and copper M1 is shown. Variation of the pulse recurrence frequency leads to similar changes in the tool electrode copying accuracy. This allows us to extend the scope of application of the pulsed mode of electrochemical machining. The correlation between the surface passivity and the effects of the pulse mode is demonstrated. A possible explanation of the observed effects using the existing theoretical background regarding the motion of charged particles in nonstationary inhomogeneous electric fields is discussed.

The investigation of influence of tool wear on ductile to brittle transition in single point diamond turning of silicon

Single point diamond turning (SPDT) of large functional surfaces on silicon remains a challenge owing to severe diamond tool wear. Recently, tremendous efforts have been made in understanding the machining mechanics, especially wear mechanism of diamond tools in SPDT of silicon. However, the localised transition of machining mode from ductile to brittle as a result of progressive tool wear has not been well understood yet. In this paper both experimental and numerical simulation studies of SPDT were performed in an effort to reveal the underlying phenomenon of ductile to brittle transition (DBT) as a consequence of diamond tool wear. Series of facing and plunging cuts were performed and the profile of machined surface was evaluated together with the progression of tool wear. The transition stages from ductile to brittle were identified by analysing the surface profiles of plunging cuts using a scanning electron microscope (SEM) and a 2D contact profilometer and a white light interferometer. The progressive degradation of the cutting edge of diamond tool and its wear mechanism was determined using Least Square (LS) arc analysis and SEM. The study reveals that at initial tool wear stage, the ductile to brittle transition initiates with the formation of lateral cracks which are transformed into brittle pitting damage with further tool edge degradation. Numerical simulation investigation using smoothed particle hydrodynamics (SPH) was also conducted in this paper in order to gain further insight of variation of stress on the cutting edge due to tool wear and its influence on brittle to ductile transition. A significant variation in frictional resistance to shear deformation as well as position shift of the maximum stress values was observed for the worn tools. The magnitude and distribution of hydrostatic stress were also found to change significantly along the cutting edge of new and worn diamond tools.

Down Milling Cutting Parameters Optimization Utilizing the Two Level Full Factorial Design Approach

The direction of feeding the work piece and cutter rotation determines the type of machining mode either it is up milling or down milling. Each of this machining mode affects the quality of machined surface produced. This paper described the experimental design of down milling operation on a stack of multidirectional CFRP/Al2024. Three cutting parameters were considered namely, spindle speed (N), feed rate (fr) and depth of cut (dc). Two level full factorial design was utilized to plan systematic experimental methodology. The analysis of variance (ANOVA) was used to analyse the influence and the interaction factors associated to surface quality. The results show that the depth of cut is the most significant factor for Al2024, and for CFRP the spindle speed and feed rate are significant. Surface roughness of CFRP is found to be at 0.594 μm at the setting of N = 11750 rpm, fr = 750 mm/min and dc = 0.255 mm. Meanwhile for Al2024, the surface roughness is found to be at 0.32 μm. The validation test showed average deviation of predicted to actual value surface roughness is 3.11% for CFRP and 3.43% for Al2024.

Operation of a quantum dot in the finite-state machine mode: Single-electron dynamic memory

A single electron dynamic memory is designed based on the non-equilibrium dynamics of charge states in electrostatically defined metallic quantum dots. Using the orthodox theory for computing the transfer rates and a master equation, we model the dynamical response of devices consisting of a charge sensor coupled to either a single and or a double quantum dot subjected to a pulsed gate voltage. We show that transition rates between charge states in metallic quantum dots are characterized by an asymmetry that can be controlled by the gate voltage. This effect is more pronounced when the switching between charge states corresponds to a Markovian process involving electron transport through a chain of several quantum dots. By simulating the dynamics of electron transport we demonstrate that the quantum box operates as a finite-state machine that can be addressed by choosing suitable shapes and switching rates of the gate pulses. We further show that writing times in the ns range and retention memory times six orders of magnitude longer, in the ms range, can be achieved on the double quantum dot system using experimentally feasible parameters, thereby demonstrating that the device can operate as a dynamic single electron memory.

An Experimental Approach to Determine the Critical Depth of Cut in Brittle-to-Ductile Phase Transition During End Milling of Soda-Lime Glass

Plastic deformation is a predominant material removal mechanism in machining of ductile materials, but it is a big challenge to achieve it in cases of brittle materials. Soda-lime glass is a very useful engineering material. Due to its favorable thermal, corrosion resistance and fine chemical properties, its common applications are in the manufacture of products like mirrors, lenses, semiconductor, and optical, bio-medical and microelectronics components. Nevertheless, owing to its brittleness due to its low fracture toughness, machining of soda-lime glass is practically impossible under normal cutting conditions. Though recent investigations have shown that machining of such brittle material is possible using ductile mode machining under controlled cutting parameters and tool geometry, it remains a challenging task. This paper focuses on identification of the critical axial depth of cut under specific feed per tooth and cutting speed in high-speed end milling of soda-lime glass. A two-fluted solid end mill of 4 mm diameter was used with cutting speed ranging from 377 to 628 m/min and feed rate from 5 to 20 mm/min to investigate the phenomenon of transition from plowing to ductile and ductile to brittle machining mode. The work piece was placed at a specific angle to facilitate machining at gradual increment in depths for different feed rates and cutting speeds combinations. At the highest available cutting speed, three phases (plowing, ductile, and brittle) were observed at a specific feed rate, resulting in a critical depth of cut 51.943 \({\rm \mu}\)m and chip thickness approximately 198 nm.

Dry machining of nickel-based super alloy as a sustainable alternative using TiN/TiAlN coated tool

Surface coating has been used to improve sustainability in machining process. Therefore, the role of advanced tool coatings in curtailing the usage of environmentally hazardous cutting fluid (CF) particularly during machining of difficult-to-cut materials needs immediate research attention. In the present work, Incoloy 825, a nickel-based super alloy, has been machined under completely dry environment using a commercially available multilayer (TiN/TiAlN) coated tool obtained using physical vapour deposition (PVD). Various machinability characteristics with primarily emphasis on cutting force (responsible for consumed cutting energy), tool wear (for tool life) and surface quality (surface roughness) have been compared with those obtained with uncoated tool under conventional flood cooling and minimum quantity lubrication (MQL). The results achieved under both rough and finish modes of machining clearly established the use of PVD coated tool under dry environment as a sustainable strategy for achieving green machining.

Intellectual Control System of Processing on CNC Machines

Scientific and technical progress makes great demands for quality of engineering production. The priority is to ensure metalworking equipment with required dimensional accuracy during the entire period of operation at minimum manufacturing costs. In article considered the problem of increasing of accuracy of processing products on CNC. The authors offers a solution to the problem by providing compensating adjustment in the trajectory of the cutting tool and machining mode. The necessity of creation of mathematical models of processes behavior in an automated technological system operations (OATS). Based on the research, authors have proposed a generalized diagram of diagnosis and input operative correction and approximate mathematical models of individual processes of diagnosis.

ТЕОРЕТИЧЕСКОЕ ОПРЕДЕЛЕНИЕ ПАРАМЕТРОВ КАЧЕСТВА ПОВЕРХНОСТНОГО СЛОЯ ДЕТАЛЕЙ, ИЗНОСА ЭЛЕКТРОДА-ИНСТРУМЕНТА И ПРОИЗВОДИТЕЛЬНОСТИ ПРОЦЕССА ПРИ ЭЛЕКТРОЭРОЗИОННОЙ ОБРАБОТКЕ

An electric erosion process serves as a basis for electroerosion machining (EEM) as a result of which occurs a material removal from the surface of a product. The destruction of electrode surface takes place at the expense of melting and partial evaporation of material. As a result of this the cavities called holes remain on a surface and also changes arise on the surface layer of a billet. A microrelief of a surface is formed with considerable quantity of mutually covered holes having different geometrics the knowledge of which allowed determining height and pitch parameters of roughness. Upon a corrugation formation at electroerosion machining has an influence a lot of factors which may be or may be not depending on a machining procedure and on whether machining is to be carried out on solid material or a surface prepared earlier should be machined. To the basic factors affecting the surface corrugation at EEM should be referred parameters conditioned on the influence of a billet initial corrugation, tool initial corrugation, influence of fluctuations in technological modes of machining. Having defined these parameters it should be possible to compute a corrugation at EEM. To analyze microhardness and residual stresses at EEM, first, it should be necessary to know a temper-ature field distribution in the surface layer of a product that will allow defining quality parameters mentioned above. To determine volumetric wear of a tool-electrode and EEM productivity it should be necessary to know the following: physical stress-strain properties of work material and material of a tool-electrode; modes of electro-erosion machining; properties of dielectric liquid.

Model Checking of Non-Centralized Automaton Web Service with AMT Bounded Constraint

In view of the web service model checking application, the combination mode of traditional finite state machines cannot guarantee the correctness of Web composite service. A web service model diction algorithm of non-centralized automaton based on satisfiability modulo theories (SMT) is proposed. First, SMT is used for bounded model checking of time automaton, and the time automaton model is directly converted into logical formula that can be identified by SMT, to make solution; secondly, the proposed SMT time automaton theory is used to achieve the employee travel arrangements web services for modeling and verification; finally, through an example analysis, the effectiveness of the algorithm on the termination of the path deadlock and the optimization of network parameters.