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The paper reports experimental research of loads (torques) that arise during cutting of corrugated fibreboard specimens by a movable cutting disc and immovable counter blades. The paper shows a method of corrugated fibreboard cutting based on the use of immovable counter blades and the cutting disc with reciprocating motion driven by electric engine. There has been designed and created experimental test bench for the research of corrugated fibreboard specimen cutting. The authors have used the strain gauge method for torque research that made possible to get their trustworthy values. The paper shows experimental research results that define technological parameters of corrugated fibreboard cutting by movable cutting disc, which minimise loads on main shaft. Results of experimental research give opportunity to get trustworthy and systematised information about torque values depending on type and thickness of the corrugated fibreboard and the influence of flute direction, cutting disc movement velocity and overlap size of tool during corrugated fibreboard cutting. The use of movable cutting disc in technological equipment for corrugated fibreboard cutting creates preconditions for high-quality manufacturing of large-sized packages from corrugated fibreboard, decreases overall dimensions and simplifies equipment design, minimises power discharge and packages manufacturing time. [ABSTRACT FROM AUTHOR]

Mechanical expansion is the key process in the manufacture of giant metallic ring. The mechanical expansion process of a 10-m-class aluminium alloy ring is taken as the research object in this paper. First, based on the springback theory of small curvature plane bending, the springback ratio formula is derived for the wall thickness centre-line of the ring cross section after unloading, and the mechanical expansion stroke model is established by the mould displacement compensation method. Then, a calculation method for mechanical expansion force is proposed by considering the friction between the mould arc surface and the ring inner wall. Moreover, a finite element model (FEM) is established to simulate the mechanical expansion process of a 10-metre-class aluminium alloy ring using MSC_Marc. The results show that the model proposed in this paper reduces the dimension error of the ring after unloading by 9.19%, and increases the calculation accuracy of the mechanical expansion force by more than 30% under different friction coefficients. Furthermore, the effects of processing parameters, centre angel of the mould segment, relative radius of the mould segment, fillet radius of the edge mould segment, ovality, expansion rate and friction coefficient on the fabricated ring quality are numerically investigated. [ABSTRACT FROM AUTHOR]

The dimensional, geometrical, thermal and tool deflection errors which have a big portion of the overall error of machined parts need more attention in precision of components produced by using CNC machine tools. As a result, it is essential to simulate and compensate the errors in the machined components in order to increase accuracy of machined parts. In order to simulate and analyse the real manufactured components in virtual environments, virtual machining systems are proposed. In this paper, application of virtual machining system is investigated in order to simulate and compensate dimensional, geometrical, thermal and tool deflection errors in 5-axis milling operations of free form surfaces. The volumetric error vectors regarding the dimensional, geometrical, thermal and tool deflection errors at each cutting tool location throughout the machining pathways are calculated and compensated utilising the study’s created virtual machining technology. In order to validate the study, a sample workpiece free from surfaces is milled by using the 5-axis CNC machine tool. The machine part is then measured by suing the CMM machine in order to obtain the dimensional, geometrical, thermal and tool deflection errors during milling operations of free form surfaces. Thermal sensors are also installed to the different locations of CNC machine tool in order to measure the thermal error of CNC machine tool during machining operations. Finally, in order to improve accuracy in 5-axis milling operations of free form surfaces, new cutting tool paths regarding the compensated volumetric errors of dimensional, geometrical, thermal, and tool deflection errors are generated. As a result, by utilising the proposed virtual machining system in the research work, precision as well as reliability during 5-axis milling operations of free form surfaces can be enhanced. [ABSTRACT FROM AUTHOR]

In this paper, numerical solutions are presented for static bending and mechanical buckling analyses of functionally graded porous (FGP) plates. The plate is modelled based on a refined plate theory and three porosity distributions with the same total mass density are considered. The set of the governing equations is derived using minimum potential energy and is solved numerically using the differential quadrature method (DQM). Convergence and accuracy of the solution are confirmed and the effects of porosity parameter, porosity distribution pattern, thickness and aspect ratio of the plate and boundary conditions on the deflection, intensity and distribution of stress and critical buckling load are investigated. It is shown by the numerical examples that an increment in the porosity parameter leads to a reduction in the critical buckling load and an increase in static deflection of the plate. Numerical results reveal that the effect of the porosity parameter on the distribution and intensity of the stress components strongly is dependent on the porosity distribution pattern. [ABSTRACT FROM AUTHOR]

This paper presents the effects of aspect ratio (0.1 ≤ A R ≤ 0.7) , Rayleigh number ( 10 2 ≤ R a ≤ 10 6 ) and inclination angle 0 ° ≤ γ ≤ 90 ° of the heated rectangular cylinder on heat transfer and fluid flow characteristics due to natural convection in air around heated rectangular cylinders of different sizes inside a cold square enclosure. Galerkin finite element method was adopted for the solution of the developed model. The walls of the enclosure were maintained at an isothermal cold temperature while the boundaries of the rectangular cylinder were kept at a constant hot temperature. The results are presented in the form of isothermal contours, stream functions, local and average Nusselt numbers. It has been found that for the range of aspect ratio and Rayleigh number considered, the rate of heat transfer increases with increasing aspect ratio and Rayleigh number. Furthermore, the orientation angle of the rectangular cylinder was found to generally augment heat transfer rate except at A R value of 0.1 , where the average Nusselt number declines beyond γ = 45 ° for all the range of Rayleigh numbers considered. Results from the present study could be applied to nuclear reactor technology and cooling of electronic chips system optimisation. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of wire electrical discharge machining (WEDM) of new fabricated aluminium base composite with 5% graphite by weight, i.e., Al/Gr/Cp5. The new fabricated metal matrix composite (MMC) has a complete application in space, defence, automobile, and other concerned metal industries. In this work, adaptive neuro-fuzzy inference system (ANFIS) and the response surface method (RSM) were selected for the analysis and modelling purposes. ANFIS is a soft computing technique used in nonlinear data training. Taguchi's L27 plan was employed to conduct the experiments. The process parameters such as pulse-on time (PON), pulse-off time (POFF), a feed rate of wire (FRW) and the input current (IC) were selected for the experimentation. Based on the experimental findings, PON is identified as the most dominant parameter and the input current. WEDM performance was measured in terms of surface roughness (SR). For the optimised (minimum) surface roughness of 1.8625 microns, the best set of process parameters was PON (108 μs), POFF (52 μs), FRW (4 m/min) and the input current (12 Amp). ANFIS-predicted results were compared with the experimental results. An acceptable agreement is observed with the high value of the correlation coefficient (R2 = 0.9624). The soft computing technique, like ANFIS-RSM, shows a good competency and reliability for the presented work. [ABSTRACT FROM AUTHOR]

Carbon fibre reinforced plastic materials (CFRPs) have a wide range of industrial applications like automobile, aerospace, biomedical, defence, and sports industries because of extraordinary multidimensional properties. Mechanical drilling is a most widely used common secondary machining process for composite laminates. Drilling induced delamination at hole-entry and hole-exit of a drilled hole is frequently occurred due to anisotropic and non-homogeneous structure of a material mechanics. Delamination can be smothered by employing tool design optimisation, upgraded drilling strategies and improving drilling methods. In this paper, various drilling conditions towards damage free drilling of CFRPs are reviewed. The above drilling conditions are categorised under adhesive layer, cryogenic cooling, minimum quantity lubrication (MQL), pilot hole, reverse air suctioning, spring-damper mechanism, support plate mechanism, variable feed strategy, etc. These strategies are extensively reviewed with reference to drill bit geometry, drilling techniques and drilling methods to uncover the significance of drilling conditions and its importance on drilled quality. This common review on various drilling conditions for delamination-free drilling can be referenced as not only a widespread summary from literature survey available till the date but also help researchers to explore new possible ways to achieve delamination-free drilling for composite materials in upcoming years. [ABSTRACT FROM AUTHOR]

The squeeze casting process blends the features of casting, forging, and also helps in achieving better manufacturing abilities; attain smooth uniform surface, high productivity, superior mechanical properties, and refined microstructure. The precise control of process variables is the most feasible solution to obtain a defect-free casting. In the squeeze casting process, surface roughness, hardness, ultimate tensile strength, and yield strength are influenced by process variables. Hence, this paper deals with the new intelligent-based squeeze casting process using LM-20 alloy. Aluminium is commonly employed in automobile and aerospace applications. The proposed casting process considers the input parameters such as squeeze pressure, pressure duration, pouring temperature, and Die preheats temperature. The output variables such as Yield strength, hardness, Ultimate tensile strength, and Surface roughness is artificially computed using the regression equations obtained for different responses using the non-linear regression models based on Central Composite Design (CCD). Initially, the considered process variables are trained in a Neural Network (NN). Further, the employed parameters are optimised to attain the best solution within the concerned limit using an improved meta-heuristic algorithm called Modified Coefficient based DHOA called MC-DHOA. The fitness evaluation of parameter optimisation depends on NN for prediction, and the objective function intends to minimise the error between optimised and target value. The analysis proves that the implemental model helps to select the most influential process parameters in the squeeze casting process within less duration. The overall performance of the proposed MC-DHOA is 16.5% better than PSO, 1% better than FF, 11% better than GWO, 4.6% better than WOA, and 2.15% better than DHOA. [ABSTRACT FROM AUTHOR]

Modern advancements and emerging trends in automobile technology have shifted the primary focus of the OEMs to make vehicles lighter, faster, and reliable. Weight has always been a major concern in commercial medium/heavy-duty vehicles. The leaf springs account for 20% of the sprung weight of the vehicle thereby making the suspension system one of the heavy components of an automobile. This paper focuses on analysing the potential of aluminium alloy as a candidate material in leaf spring so as to make the suspension system lighter and more reliable. Aluminium alloy is one of the appropriate materials to proceed with because of its lightweight, strength, and non-significant deformation during load cycles. Three-dimensional CAD model of standard leaf spring was created in DS CATIA V5R19 software and computational analysis were carried out in ANSYS Workbench 18.1 by defining material as plain carbon steel (structural steel) and Aluminium alloy for comparative study. The results of the analysis that the reduction in weight of the leaf spring using aluminium alloy was approximately 64.71% along with a significant reduction in equivalent stress induced at different loading condition with a maximum reduction of 45.30% equivalent stress at the fully loaded dynamic condition. [ABSTRACT FROM AUTHOR]

This paper reports a numerical investigation of the effect of aspect ratio (AR) on the flow structure around the 35° Ahmed body. The AR is defined as the ratio of length to the height of the model. A total of five ARs are considered at a Reynolds number based on the height of the Ahmed body of 7.8 105. The flow governing equations are solved in the FLUENT solver using the SST K-Omega turbulence model. It is found that the drag coefficient (Cd) slightly increases at the AR1 4.2%. As the aspect ratio increases, the drag coefficient decreases. The analysis reveals that early flow separation in the AR1 causes a reattachment at the rear slant end, which leads to an increase in drag. It also highlights that there exists a minimum aspect ratio beyond which the drag increases. and there is a limit in the increasing order beyond which the drag will begin to reduce. Further, it demonstrates that there is no change in the recirculation region and consequently drag coefficient is not a function of the recirculation region. Thence, a clear understanding of the effect of the length-based aspect ratio can help to optimize the length during design. [ABSTRACT FROM AUTHOR]

Since installing speed sensors on the grinding head for high-speed precision roll grinders is not feasible, it is necessary to use direct torque control (DTC) without speed sensors, and its control system requires high estimation accuracy. In this paper, speed estimation methods using extended Kalman filter (EKF) and model reference adaptive system (MRAS) have been used to realise speed estimation in the DTC system of the spindle motor of the grinding head for a high-speed precision roll grinder. The simulation results showed that the EKF method has relatively high accuracy and a fast convergence speed for the estimation speed of the spindle motor of the grinding head for a high-speed precision roll grinder by comparison with the MRAS method. Moreover, the EKF method was also able to overcome the nonlinear and parameter uncertainty of the operating system of the motor and strongly immune to the noise interference of the system. Finally, the speed estimation accuracy of the motor using the EKF method had better than the MRAS method. Therefore, this work provides a general approach to applying the DTC without speed sensors for the motor and further lays a solid foundation for developing high-speed precision roll grinders. [ABSTRACT FROM AUTHOR]

People across the globe witnessed the meteoric rise of the recently discovered coronavirus, which caught governments, healthcare systems, and civilisations off guard. Robotics, self-governing systems, and intelligent devices can contribute positively to a rapid epidemic. Smart assistive robots can help patients and healthcare staff in general and make the anticipation, containment, and exacerbation of coronavirus easier by highlighting the coronavirus burden on healthcare structures during a crisis. In this type of situation, a smart-assistive robot with aid capabilities is promising, especially for those putting their lives in jeopardy by interacting with ill patients in hygienic environments. By providing regular monitoring and patient assistance, the intelligent helper robot could assist in lowering the danger of illness spreading to others. Concerning the application this paper discusses, a robot with a wheeled base and a humanoid structure can aid isolated patients and connect wirelessly anywhere in the world (using the Internet of Things) with patients far away more effectively without any physical touch. The designed robot is incredibly light (approximately 7 kg) and easily transported to the appropriate location (any hospital or medical camp, for example). Its modular design allows quick assembly and disassembly. The robot can comfortably handle 10–15 kg of load on its holding plate. This study also explains the structural capability and method of directing the robot in an unfamiliar area using ultrasonic sensors for obstacle avoidance, a camera module for real-time vision, and a Skype call feature that may enable doctors to keep tabs on a patient’s health. [ABSTRACT FROM AUTHOR]

Fused decomposition modelling (FDM) is a sustainable additive manufacturing process of the 21st century. Due to the increasing trend of customer-oriented manufacturing processes, FDM can provide a better solution for the manufacturing industry. However, it suffers from a lot of hindrances like high build time, inadequate strength, low surface roughness, the requirement of the support structure, and materials constraint during producing overhanging parts. Therefore a holistic approach to producing overhanging parts is required for any FDM industry. Based on a vast literature survey and performing pilot basis experiments, some good technical and managerial insights have been suggested for improving the quality of FDM products in terms of surface roughness, strength, and proper selection of materials. Another salient feature of the research paper is to provide an integrated reconfigurable mould based FDM approach for producing overhanging parts. The proposed integrated systems not only eliminate the requirement for a support structure but also decrease the build time. Some pilot basis experiments have been carried out for producing overhanging parts, which reveal that the proposed integrated systems eliminate the requirement of the support structure and, it also decreases build time approximately by 15% and materials requirement by 30%. [ABSTRACT FROM AUTHOR]

This paper presents a new investigation of the recirculation channel combined with bleeding channels, where the recirculation airflow recirculates air from downstream high-pressure region to an upstream through a recirculation channel located on shroud surface in rotor domain and the bleeding airflow through 36 bleeding channels sited on the recirculation channels ejects airflow to the by-pass channel in a single-stage transonic axial compressor used in turbofan engine. The object of this investigation is to reduce the vortex flow in the tip leakage region by finding the effects of recirculation and bleeding channels design on aeromechanic performance of a single-stage axial compressor, NASA Stage 37. A parametric study of the recirculation and bleeding channels were performed using various geometric parameters related to the locations and shapes of the recirculation and bleeding channels to find the effects of recirculation and bleeding channels design on aeromechanic performance, such as pressure ratio, efficiency, stall margin, blade tip deformation and Von-Mises stress. The numerical results showed an increase in aerodynamic performance and decrease in blade tip deformation with recirculation-bleeding channels, compared to the smooth casing. [ABSTRACT FROM AUTHOR]

This paper proposes an analysis of Mounting Bracket Structure and Material effects on fixed-displacement swash-plate-type compressor. To decrease the interior sound pressure of a vehicle, both finite-element analysis (FEA) and vibration experiment of the automotive air conditioning compressor with the mounting bracket were conducted, and the effect of the material and structure of the mounting bracket on the noise and vibration of the compressor was analysed. The finite-element model of the fixed-displacement swash-plate-type compressor with a mounting bracket is established. For the mounting bracket with different materials and structures, vibration acceleration level (VAL) of the finite-element model was analysed. Results show that the mounting bracket MB3, which is made of QT400-10, provides the best noise and vibration performance, which is also verified through interior sound pressure level experiment. Abbreviations: FEA: finite-element analysis; VAL: vibration acceleration level; FRA: frequency response analysis; EMA: experimental modal analysis; LTI: Linear Time-Invariant; FEM: finite-element model; AMS: automatic multi-level substructuring; DOF: degree of freedom [ABSTRACT FROM AUTHOR]

The Selection of appropriate phase change material in the field of domestic water heating system is a difficult task due to the availability of the variety of an enormous number of different materials. The researcher's primary objective is a selection of the desired PCM, which will give the best thermal performance of the domestic water heating latent heat storage system. The paper reports the selection of phase change material with three multi-criteria decision-making (MCDM) methods with conflicting and different objectives. An analytic hierarchy process (AHP) and entropy methods are used to determine the importance criteria weights. For selection purpose, the TOPSIS (Technique for order performance by similarity to ideal solution), VIKOR (Vise KriterijumskaOptimizacijaKompromisnoResenje), and EXPROM2 methods were used, which gives ranking to the alternatives using compromised weight obtained by AHP and entropy methods. This MCDM technique provides a list of all desirable options from the best to the worst suitable materials. Depending on the rankings obtained, the best PCM was found to be the Sodium acetate trihydrate (90%) + graphite (10%), Stearic acid and n-Hexacosane at the given criteria due to its higher physical, chemical, and thermal properties than other alternative PCM materials. The results obtained showed that these methods are feasible tool for the Selection of the best-suited phase change material and can be applied to any material selection decision-making problem to find the best materials. [ABSTRACT FROM AUTHOR]

Internal mixing twin-fluid atomiser is known to be one of the prominent atomisers for the generation of spray or spray-like dispersion from bulk liquids. This paper designs and investigates the performance of a customised liquid siphon type internal mixing twin-fluid atomiser for the generation of test aerosol particles from oleic acid in an ethyl alcohol solution. Experimental results show the effect of airflow rate on suction height and liquid consumption rate of the atomiser with different design parameters. Variation of suction height and liquid consumption rate are investigated for six different design atomisers by varying the airflow rate between 18 and 230 lpm. It is seen that the atomiser with optimum design can have a suction height of up to 103 cm and a liquid consumption rate of up to 1545 ml/h. Atomiser 3 (with air inlet diameter = 18 mm and liquid jet diameter = 2 mm) produces better test aerosol participles with constant S/D = 0.66 and 10% solution concentration. While using this atomiser for the production of test aerosol, the lowest geometric standard deviation found in the experiment was 1.2. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) technology has been developed for more than thirty years and has become a mainstream manufacturing process. Sustainability is becoming increasingly significant for human's health. In recent years, studies have been carried out to make AM a sustainable manufacturing technique. In this paper, research in improving manufacturing sustainability of material extrusion AM is reviewed. Studies with the aim of saving material, production time and energy in material extrusion AM processes are discussed. Future potential research directions are also identified for making AM more sustainable in the future. [ABSTRACT FROM AUTHOR]

The application of nanotechnology in the welding process has great importance in developing the mechanical properties of welding joints. The aim of this paper was to investigated the effect of addition titanium dioxide nanoparticles(TiO2) to welding joints by using cold spary technique and study the possibility of improving the impact toughness of the welding joint and increase its operation life. Three weight fraction are used of TiO2 (0.75%, 1.5%, and 2%).The results showed there are improvements in the Impact toughness of welded joints with an increase of TiO2 concentrations. The average Impact toughness for the welded sample without TiO2 was (162.4 J), while the average Impact toughness for the welded sample with (1.5) % TiO2 NPs. was (231.2 J) at increasing ratio of (42.36 %) due to the good toughness properties of TiO2 that increase the toughness of welding zone. The Microstructure image by SEM showed that the addition of TiO2 decreases the grain size in the welding zone and makes it more homogeneous, which gives it more toughness. The EDS analysis shows that increase TiO2 NPs leads to increase the amount of Ti and decrease the amount of Mn, and Si. [ABSTRACT FROM AUTHOR]

The main purpose of any vehicular climatic control in terms of heating and air conditioning (AC) systems is to achieve maximum thermal human comfort with energy efficient. Therefore, it is important to analyse the temperature distribution and air-flow field in the cabin compartment to achieve the highest and rapid human comfort. This paper adopted a Berkeley human comfort model to show the behaviour of a vehicular human sensation and comfort at different airflow velocity levels. A temporal history, local sensation (LS), and comfort (LC) were analysed for different body segments with the addition of the overall sensation (OS) and the overall comfort (OC) inside the passenger compartment under summer period weather conditions. This study revealed that: because of the air velocity plays crucial impacts on both convection and evaporation mechanisms which directly effects on the heat losses from the body and thermal human comfort, the controlling of air movement with the temperature helps the environmental cabin to achieve the comfort zone faster than the sole control of the temperature only. When activated the air conditioning systems, the vehicular environmental parameters will change dramatically and a rapid transient occurred especially in the first few minutes. [ABSTRACT FROM AUTHOR]

To avoid installation dispersion and improve the data transmission efficiency of the submarine oil and gas production system, the concept of function module with a vertical layout is presented. Meanwhile, the wireless sensor network is introduced to monitor the function module. For a high-efficiency wireless sensor network, the node deployment method is crucial and essential. In this paper, the model of the region to be monitored is established, and an improved isosceles triangle node deployment method is proposed based on the traditional disk perception model of the sensor node. The coverage density and coverage efficiency of the single and double coverage of this improved method are also calculated. By comparing the coverage performance of the traditional method (TM) and the improved method (IM), the results show that the single and double coverage density of the IM are both smaller. The introduction of the IM decreases the cost of the perception coverage of the side of the function module and establishes a foundation of the remote monitoring of the function module. [ABSTRACT FROM AUTHOR]

This paper presents the outcome of a study on the effect of the machining conditions on some performance parameters during dry and hard boring of ASTM A304 low alloy steel round bar with tungsten-carbide insert using a 3-level factorial design of experiment-based response surface methodology. It involved modelling, prediction and optimisation of the performance parameters subject to constraints on variation of the machining conditions. Within the limits defined by levels of the machining, the performance parameters were randomly determined in 27 runs of boring experiments. These experiments, which were performed on a D360 x 1000HS excel lathe machine, serial no J320581, involved dry and hard boring of 27 ASTM A304 low alloy steel specimen work-pieces using tungsten-carbide inserts at different levels of low, medium and high as specified for the machining conditions. The data analysis was performed using Design Expert software version 9.0.6.2 to model, predict, and to obtain the optimal machining conditions, and the corresponding performance parameters. The study revealed the control factors to have varying effects on the response variables of which the prime factor is the cutting speed, for the tool wear and cutting temperature, and depth of cut, for the material removal rate. Hence, it is recommended that the obtained values of these factors should be adopted for optimal machining of the aforementioned material. [ABSTRACT FROM AUTHOR]

Air conditioning systems are the most viable source to avoid heat waves. Unfortunately, this puts a massive burden on the total electrical load. To deal with this critical issue, the Saudi Building Code National Committee has initiated the Saudi energy conservation code (SBC-602). This paper investigated the role of SBC-602 on the reduction of energy consumption in residential buildings. Furthermore, it also proposes the most effective building element to be insulated. A case study of energy consumption was modelled using SketchUp and analysed using OpenStudio Software. Inconsequence, three scenarios of U-values as an input in this work were suggested which are; building without thermal insulation, building with thermal insulation using Saudi electricity company (SEC) requirement, and using SBC-602 requirement. The study was conducted in three different cities Riyadh, Hail, and Abha, representing three climate zones in Saudi Arabia. Design of experiment (DOE) method was utilised to analyse the significant effects of the input factors. The result indicates that the decrease of the walls U-value is the most effective way to reduce the total electrical energy consumption. Moreover, decreasing roof U-value and increasing setpoint temperature were the following effective factor. [ABSTRACT FROM AUTHOR]

In terms of reliability, the damper represents the critical element of the suspension in the rail vehicle. A damper failure brings about a reduction in the damping of the suspension it belongs to, thus leading to the asymmetry of the suspension damping in the vehicle. The paper presents an analysis of the effect that the asymmetry of the secondary suspension damping has on the vertical vibration behaviour in the vehicle carbody and on the ride comfort, while using to that purpose the results derived from numerical simulations. The characteristics of the vibration behaviour for the resonance frequencies of the carbody dominant vertical modes are pointed out via the power spectral density of the carbody acceleration, which is weighted by the function of the sensitivity of the human body to the vertical vibrations. The ride comfort is assessed based on the ride index comfort calculated in three carbody reference points – at the centre and above the two bogies. [ABSTRACT FROM AUTHOR]

The electromagnetic arc constriction technique was implemented to mitigate the heat input related weldability issues in Tungsten Inert Gas (TIG) welding of Alloy 718 particularly solute segregation and substantial laves phase evolution in fusion zone which significantly deteriorates the strength and elongation of welded joints. This paper reports the direct effect of arc constriction current (ACC) on microstructural evolution and tensile properties of Constricted Arc TIG (CA-TIG) welded Alloy 718 joints. ACC is the important parameter which induces the electromagnetic filed and controls the arc constriction characteristics. The basic mechanism responsible for microstructural modification and corresponding influence on the tensile properties of joints is studied both in quantitative and qualitative manner related to the mechanics of electromagnetic arc constriction and correlated to the cooling rate. The joints made by applying ACC of 50 A yielded superior tensile properties. It is correlated to the grain refinement of fusion zone resulting in the evolution of laves phase with finer discrete morphology in interdendritic spacings. Increase in ACC above 50 A causes severe growth of grains in fusion zone and substantial decrement in tensile properties of joints. Beneficial effects of ACC were not perceived at maximum level owing to the high heat input. [ABSTRACT FROM AUTHOR]

Composites made of Glass Fibres are finding increasing applications in various sectors because of their higher specific strength and better resistance to corrosion. Drilling is the most frequently used machining process used in the composite industry specifically for assembly purposes. The primary focus of this paper is on the factors that determine the quality of the drilled hole in Glass Fibre Reinforced Polymer composite materials. A slab with randomly oriented glass fibres was manufactured. Taguchi's L9 orthogonal array with varying diameter, spindle speed, and feed rates was used to design the experiment. Drilling was performed with Solid Carbide drill bit and thrust force was recorded. Post drilling, non-destructive tests for roughness, roundness, and delamination were conducted to characterise the drilled holes. The results showed that at lower feed rates and higher speed better quality of drilled holes were obtained. [ABSTRACT FROM AUTHOR]

The paper presents the prediction of surface quality during the electro-discharge machining (EDM) of aluminium-based alloy. The composition consists of Aluminium, copper, nickel (Al/Cu/Ni) alloy. The techniques like dimensional exponential model (DEM), response surface-based modelling (RSM), and adaptive neuro-fuzzy inference based system (ANFIS) were employed to analyse the EDM process. Response variable i.e. Surface characteristic measure in terms of roughness (Ra) is the dependent parameter. Experimental analysis was done using Taguchi's L18 mixed OA's i.e. orthogonal-array by considering the process parameters namely variation in the material composition (CP), pulse-on-time(TON), pulse-off- time(TOFF) and input current(IP). Analysis of variances (ANOVA) has been employed out to identify the significant process parameters and their impact over surface characteristics. Models based on the DEM and RSM were developed to analyse the surface characteristics or roughness of the Al/Cu/Ni alloy. The experimental result proves the commitment of all three approaches to represent the process effectually. The correlation coefficient (R2) between the experimental and the DEM, RSM, and ANFIS predicted roughness was 0.830626, 0.995649, and 0.999958 respectively. This value shows the dominance of the ANFIS technique over the DEM and the RSM. [ABSTRACT FROM AUTHOR]

The compressor transition duct transfers the air from the low-pressure compressor to the high-pressure compressor. An aircraft always experiences off-design conditions except for level flight conditions during aircraft range. So, to throw some light on the performance of transition ducts under off-design conditions, this paper presents its performance assessment numerically for uniform and swirl flow cases under varying Mach numbers (M). This analysis reveals that a higher Mach number provokes an adverse pressure gradient and non-uniformity. In the uniform flow, the non-uniformity attains a maximum value of 0.04366 near the inner wall, which indicates the presence of a highly distorted flow near the inner wall; however, its maximum value is 0.03661 near to the outer wall in the swirl flow. Also, the pressure recovery reduces with an increased Mach number. Notably, as the Mach number increasesfrom the design point, the pressure coefficient along the convex curvature significantly drops to the lowest point of −0.65015 and −0.79324 for uniform and swirl flow, respectively. Consequently, the inner wall experiences a large adverse pressure gradient (−0.90822) compared to the decreasing Mach number from the design point for the uniform flow, whereas it is experienced by the outer wall in the case of swirl flow (−0.94729). [ABSTRACT FROM AUTHOR]

In this paper large deformation of the skew microplate made of laminated composite enhanced with graphene nanosheets is investigated using first shear deformation theory (FSDT) when the plate undergoes combination of mechanical and thermal loads. Halpin-Tsai model is utilised to model mechanical properties while for thermal properties Schapery model is considered. First, shear deformation of the plate was obtained while using Green-Lagrange tensor the non-linear strain of the microplate is extracted using the von-Karman assumptions. Then, by Modified Coupled Stress Theory (MCSD), the components of Cauchy and Couple stress tensors are specified. Finally, using Hamilton Principle the governing equation of the microplate and boundary conditions are computed. After deriving analytical governmental equation results are presented for the simple support boundary condition and the proposed model is validated by previously reported data and it proves to be promising. Primary results showed that with raising skew angle deflection and bending moment decreases which means microplate becomes more rigid in higher skew angles. Higher mechanical loads lead to higher deflections and bending moments. Four different configurations of the layers were analysed from which angle-ply configuration possessed highest deflection and bending while UD configuration revealed the lowest values of deflection and bending moment. [ABSTRACT FROM AUTHOR]

In this paper the effect of incremental rise of tyre pyrolysis oil in the blend is analyzed to explore the performance and emission parameters of a single cylinder VCR diesel engine. During experimentation proportion of TPO were 10, 25, 35, 50, 60, 75 and 90 % with diesel fuel. Tests were conducted using four different loading conditions. The experiments were performed using an analytical tool known as Design of Experiments on the basis of Response Surface Methodology. The conclusive models of the RSM prepared to predict the response criterion such as BSFC, BTE, CO, nitrogen oxides, smoke and Mechanical efficiency. The results depicted that with rise in the load, BSFC decrease while it increases with rise in TPO proportion and found lower at 50% TPO and increases again above 50% TPO. BTE increased with increase in the load and found to be highest at higher TPO. For all blends, an increase in Nitrogen oxides found with increase in load and TPO proportion. Parameter optimization executed using the desirability approach method of the RSM for improved conduct and reduced emissions. A load of 4.57 kg (61.7567%) and 40.94% TPO in the blend are suggested as the optimal criterion for the test engine. [ABSTRACT FROM AUTHOR]

This paper is intended to study mechanical, corrosion and cavitation erosion properties of aluminium metal matrix composites with Multiwalled carbon nanotubes (MWCNTs) as reinforcement. Multi-walled carbon nanotubes in different weight percentages (1, 2 and 3%) are reinforced in Light metal 9 (LM 9) aluminium alloy using the ultrasonic stir casting method. Hardness, pitting corrosion potential and erosion resistance are evaluated to assess the influence of different weight percentages of MWCNTs as reinforcements in LM 9 alloy. The results indicate that Aluminium – MWCNTs composites possess an improved hardness of up to 150 % compared to base LM 9 alloy. The pitting corrosion resistance of composites was found to be excellent with minimum corrosion damage to the composite specimen. Cavitation erosion test performed as per ASTM G32 indicates a decrease in erosion wear for composites reinforced with MWCNTs compared to base material LM 9. The property improvement of the LM 9 – MWCNT composite under dynamic conditions is verified using SEM micrographs. The effect of weight percentage of MWCNTs found to be significant in the enhancement of properties. There are 16 % and 30 % reductions respectively in pitting corrosion potential and erosive wear respectively for composite with 3 % MWCNTs. [ABSTRACT FROM AUTHOR]

This paper presents the experimental study of the compression, tension, and lifting stability test on a meter gauge flat wagon. The freight wagon comprises flat body structure and two bogies, where the flat surface is used to transport containers or goods. Two load cells (2000 KN) of HBM Quantum X-MX840 with CATMAN easy software is used for the compression, tension, and lifting stability test. As per EN 12663-2:2010 standard for axial compression test maximum force of 2MN is applied while for diagonal compression test 0.4MN force is applied. The tension test is carried out by applying a maximum tensile load of 1.5 MN while the lifting test is performed with 29T (empty condition) and 57.5T (loaded condition) wagon load. Strain gauges are pasted on identified critical location (based on FEM simulation in ANSYS) of the wagon to capture the strain values. The steady-state strain values are measured and recorded in a data acquisition system. A standard test methodology and the testing setups are established for freight wagon testing. The measured strain values are analyzed for the wagon specific requirements. It is observed that during testing strain values are within the safe zone as per the designed payload for this wagon. [ABSTRACT FROM AUTHOR]

Variable-thickness rolled blank (VRB) technique is one of the most effective methods to improve the level of lightweight and stiffness characteristics of car body. The shape of thickness transition zone (TTZ) is a key factor for the stiffness characteristics of VRB. For better stiffness characteristics of VRB, a new thickness distribution function (i.e. double-power function) of the transitional zone of VRB is proposed in this paper. Firstly, the mathematical model of the VRB with double-power thickness distribution function is established under manufacturing constraint. Secondly, the static stiffness characteristics of VRB with double-power thickness distribution function are compared with that of the VRB with linear thickness distribution and polynomial thickness distribution under the same weight, respectively. The results show that the static stiffness of the VRB with double-power thickness distribution function owns best characteristics. Finally, the mathematical model of the rolling velocity is established, and the influence of the shape of double-power TTZ on rolling velocity is analysed. The outcome of this work can provide some useful guidance for investigating the rollability of the VRB with double-power thickness distribution function, as well as for designing the stiffness of car body outer panels. [ABSTRACT FROM AUTHOR]

Profile shift of the gear significantly affects its form, zone, stress factors, transversal and face load factors. In this paper, an optimum solution to the problem of mating helical gears design considering profile shift is given. The objective of the problem is to minimise volume taking into account tooth root bending strength, contact pressure, face width, and addendum modification coefficients as constraints. The design variables, namely, the module, the face width, the number of teeth, and profile shift coefficients of both gears are considered. Nature-inspired algorithms, namely, Simulated Algorithm (SA), Fire Fly Algorithm (FA), Cuckoo Search (CS), Particle Swarm Optimisation (PSO) and Teaching Learning-Based Optimisation (TLBO) algorithms are employed. Results of simulation with and without profile shift, performance of various algorithms are analysed and validated with literature. Results show that CS and PSO algorithms give the best optimum volume. They also significantly reduce volume by 1.91%, when compared to literature. CS algorithm gives the best optimum design parameters. Furthermore, results show the volume of the mating helical gears with profile shift is much lesser than the pair without profile shift. [ABSTRACT FROM AUTHOR]

This paper presents the full scale experimental as well as software analysis investigation of Gerber frames subjected to elastic lateral torsional buckling (LTB). To understand the elastic buckling load, three experiments were undertaken and recorded the buckling modes. To predict the elastic LTB resistance, shell finite element (FE) solution was conducted. A comparison is made among the experimental elastic buckling load and results obtained by FE model for Gerber frames. A good agreement is observed between experimental and finite element analysis. [ABSTRACT FROM AUTHOR]

Residual stresses become a huge obstacle to improve the quality of precision manufacturing. They impact the static strength, fatigue strength, and corrosion resistance of the manufactured parts seriously. Complexity of the residual stresses initialising, generating, and redistributing still makes it difficult to efficiently control their distribution. In this paper, a new approach based on stress wave is proposed to reveal the propagation mechanism of residual stress in depth during the milling process. An elastic longitudinal wave and a plastic longitudinal wave equations are established. The analytic expression of the stress wave in the real domain is obtained by Laplace transformation and Laplace inverse transformation. The propagation of stress waves in two-dimensional milling is simulated with Finite Element Method (FEM). A simulation case study has been performed in order to demonstrate the practicality and effectiveness of the proposed approach. The simulation results show that the simulated elastic wave propagation velocity agrees well with the theoretical one. The peak value of the milling stress wave decreases with the unloading. The influence of cutting thickness on the decay rate is larger than that of cutting speed. [ABSTRACT FROM AUTHOR]

Coatings have been used tremendously in the recent past for the improvement of mechanical and tribological characteristics of machine elements and metal cutting and forming tools. The study of thin surface coatings has immersed as the large area of interest these days for friction and wear reduction, fatigue life enhancement and reliability in research community and industry. This paper presents the study related to tribological properties of Tungsten carbide/carbon (WC/C) coating for case carburising steels. Two different steel materials namely 20MnCr5 and SAE 8620 were investigated on a pin on disk machine in dry conditions. A strong correlation was found between the surface roughness and the friction coefficient. [ABSTRACT FROM AUTHOR]

Joint clearances need to be specified for the assembly and operation of mechanisms. When the joint clearances are determined while designing, it ensures the robust operation of the mechanism. The robustly designed mechanisms perform the specified tasks with the least deviation. The validation of such robustly designed mechanisms by fabricating experimental setup is a difficult task. Simulated analysis of the parametric model of such robustly designed mechanisms can be done using suitable software. In this paper, the effect of joint clearances on the displacement of the slider in a slider-crank mechanism has been discussed. A slider-crank mechanism with adjustable joint clearances at both ends of the connecting rod has been designed. Three pin pairs have been designed for generating adjustable joint clearances. Two models of the slider-drank mechanism have been developed in ADAMS/View. The first one has been without joint clearances and the second one has been with adjustable joint clearances. The simulated results of without clearance model validate the slider displacement at ideal conditions. The simulated results of the adjustable joint clearance model have been experimentally validated using an experimental setup. [ABSTRACT FROM AUTHOR]

This paper presents sensitivity analysis of stress behaviour in the elements of bicycle frame having diamond structure with respect to design parameters. In order to achieve this goal stress on each element of the diamond frame have been derived in the form of analytical expression in terms of design parameters by imposing static equilibrium condition on 2D representation of the frame. Stresses on all the elements and reactionary forces on the frame are linear combination of two external loads on the frame with coefficients being trigonometric expressions. Stresses on all elements and reactionary forces have a common term which appear as denominator and is termed as Inter-element Interaction Common Factor (IICF). Analytical expressions for stresses on elements have the potential to provide insights into the set of values of design parameters for optimization of bicycle frame with respect to various criteria. Such insights, in addition to being valuable for designers using computer aided engineering softwares like ANSYS, are also helpful for comparative analysis among various design criteria. [ABSTRACT FROM AUTHOR]

In this paper, finite element analysis and response surface methodology (RSM) were used to analyse and study the stress concentration factor (SCF) of a uniaxially loaded isotropic plate with a centrally placed countersunk hole. In this study, the finite element (FE) model was built in ANSYS and employed to generate SCF values. This FE model was first optimised in terms of mesh properties and then validated with literature data. Using RSM, the effect of the plate and countersunk hole geometries, which was implemented by four dimensionless parameters, on the SCF was presented. Additionally, as suggested by RSM and using ordinary least squared method, a high-accuracy second order equation to predict the SCF value based on the non-dimensional geometric factors was formulated. Finally, this paper suggests an optimum plate and countersunk design geometries to minimise the SCF in countersunk holes in isotropic plates. [ABSTRACT FROM AUTHOR]

To overcome such Hybrid Electric Vehicle (HEV) engine problems as high fuel consumption and poor economical efficiency when working in low-efficiency areas, this paper intends to establish the ISG light hybrid vehicle structure-based mathematical models of engines, electric motors, batteries and the whole vehicle power output first; to analyse the relationship between the engine load rate and the optimal engine fuel consumption characteristics, and then to take into consideration the performance characteristics of the motor battery output efficiency, so as to come up with the switching pattern of the ISG parallel hybrid vehicle operating mode. According to the switching rules, the primary influence parameters of the engine load rate as well as the State of Charge (SOC) were extracted and a fuzzy neural network control strategy for torque management was developed. Under the Matlab/Advisor joint simulation platform, a simulation model was established and the effectiveness of the fuzzy control strategy was verified under the typical state of cyclic operation NEDC. The simulation results indicate that the adoption of fuzzy neural network control strategy for torque management can lead to considerable advancements in engine operating efficiency–the fuel economical efficiency can be improved by about 12%. [ABSTRACT FROM AUTHOR]

An adjustable or controllable form of bearing geometry embodying four multiple pads circumferentially positioned around the journal is presented in this study. The proposed pad geometry has a novel feature to undergo radial and tilt adjustments in both inward and outward directions from the reference position. The adjustability principle of bearing pads helps to attain a controlled bearing operation in the clearance spaces. This paper investigates the effect of offset loads on the steady-state characteristics of a four-pad adjustable bearing. A modified film thickness equation is applied to take account of the radial and tilt pad adjustments in the theoretical analysis. Variation in fluid film pressures and static characteristics is analysed for different pad adjustment conditions and offset load positions. From the comparative study, superior static performance is obtained for bearing operated with an offset load of χ/α = 0.45 and negative pad adjustment configurations than compared with central load condition. [ABSTRACT FROM AUTHOR]

Biomaterials are synthetic and natural materials that restore or replace the part of the body to improve human health by functioning the natural living tissue or organ. It should be biocompatible, biodegradable or bioabsorbable depends on the application. Biomaterials could be metal, polymer and ceramic or combination of these. This paper reviews all types of biomaterials and their particular application mainly focusing on metallic materials. Metallic materials mostly used are Titanium alloys, Co-Cr alloys and stainless steel alloys. Presently Stainless steel 316L is widely used and the effect of a different parameters such as manufacturing process, composition, heat treatments and surface treatment on biocompatibility of stainless steel 316L are discussed in detail. [ABSTRACT FROM AUTHOR]

A multi-component measurement system centred on piezoelectric force sensor is an important mechanical measurement device, in which the piezoelectric sensor is mainly composed of force-sensitive components. The force-electric conversion performance of quartz wafer containing seed crystal and quartz crystal wafers is the main issue of the research in this paper. In the way of microscopic imaging and X-ray diffraction spectrum analysis, based on macroscopic physical properties of crystals, the theoretical basis of piezoelectric effects and the Neumann principle of elastic mechanics, both kinds of crystals have the same matrix of positive piezoelectric effects. Through static and continuous loading tests on quartz wafer containing seed crystal and ordinary quartz wafer, the maximum deviation of the electric charge, respectively, generated by X0° and Y0°cut type seed crystal wafers and ordinary quartz wafer in the static test under the same vector force loading is finally obtained, both seed-containing wafer and ordinary quartz wafer have excellent linearity. In continuous loading test, seed-containing wafer also has good continuous loading performance and can maintain a stable charge output under quasi-static input. Therefore, it is concluded that seed crystal wafers can also be used for actual testing. [ABSTRACT FROM AUTHOR]

Recent advances in Minimally Invasive Surgery, multifunctional instruments are essential to improve the efficiency of the surgical procedure. Surgical instruments with combination of wire and links demonstrate high performance, but fabrication and assembly of the instruments are challenging. This open the way for alternate design, and compliant mechanism is the appropriate choice. Compliant mechanism is the flexible mechanism that transfer loads from one point to another through elastic body deformation. This research paper introduces the novel design of compliant forceps, which can cut and collect tissues. Forceps require very high force to cut the tissues and less force to collect the tissues. The concept is developed with respect to the requirement, where switching of functions can be obtained by applying respective input actuation. The concepts of compliant forceps are converted to the realistic model using parameterisation technique. Structural performance of compliant forceps is investigated through the finite element method (FEM). FEM is used to measure the cutting force and grasping force. [ABSTRACT FROM AUTHOR]

The main purpose of this paper is to present a novel Robust Design Optimisation (RDO) strategy based on an efficient Uncertainty Analysis (UA) approach. To this end, a Progressive Latin Hypercube Sampling (PLHS) method was developed to derive the minimum samples for UA. The required sample size is calculated based on the convergence of the UA results. Therefore, UA is achieved by a variable sample size Design of Experiments (DOE). This systematic approach leads to an efficient, adaptive and fast framework for RDO. The proposed algorithm performance was validated by some numerical simulations methods on a benchmark function. In conclusion, the proposed methodology was utilised to the design of a hydrazine catalyst bed as a case study. The results of applied RDO in catalyst bed design parameters and also the corresponding value of objective functions demonstrates the performance of the developed framework in space applications. [ABSTRACT FROM AUTHOR]

In this paper, numerical simulation of transient thermal and static structural analysis was performed here sequentially with coupled thermo-structural method. Numerical procedure of calculation was based on important steps such as the Computational Fluid Dynamics (CFD) and thermal analysis which were well illustrated in 3D. Two different rotor designs and three different brake disc materials were tested and comparative analysis of the results was here conducted in order to get the one with the best thermal behaviour. The current numerical results were in good agreement with the previous experimental results available in the literature. Finally, the resolution of the thermo-mechanical coupling model allows us to visualise other important results of this research. According to the results presented in this study, several conclusions can be drawn. The choice will allow us to deliver the excellent rotor design to ensure and guarantee the good braking performance of the vehicles. [ABSTRACT FROM AUTHOR]

Their attractive mechanical, electrical & thermal properties, superior to state-of-art materials currently being used, results in improving the performance of polymer matrix composites. The challenge is to identify the required potential application of CNT composites for space use. Moreover, it needs space qualifications including material, process & product qualification. This review paper states a few potential applications of Nanofiller composites for space payload components. It also states challenges and requirements for space applications as well as space qualification. [ABSTRACT FROM AUTHOR]

A satellite attitude dynamics simulator (SADS) is a low-cost, ground-based equipment for laboratory simulation of the space environment as satellite weightless, sun and magnetic field simulation as well as implementation of diverse attitude determination and control algorithms. Precise estimation of mass properties plays a significant role in guidance and control algorithms application. The objective of this paper is mass properties identification includes moment of inertia tensor and centre of mass position of a three-degrees-of-freedom SADS at the Space Research Laboratory. This paper investigates the well-known methods to estimate mass properties, i.e. Batch Least Squares and Classical Kalman Filter and presents an innovative approach using the Classical Levenberg–Marquardt (CLM) to solve this major problem. In order to verify the proposed technique, a MATLAB® SIMULINK® model of the SADS is employed. The experimental results indicate that the parameter estimation process using CLM technique is more accurate and reliable than other methods. [ABSTRACT FROM AUTHOR]

Aluminium honeycomb cores were predominantly used in transportation and aerospace sectors because of its outstanding structural and better mechanical properties. In the recent studies, it was found that carbon fibre-reinforced polymer composites (CFRP) tubes also can be used as a filler material to benefit out an improved mechanical behaviour. Until now, many research studies are done on CFRP-filled honeycomb to analyse the energy absorption phenomenon for axial impact loading. Always there is a demand exists to investigate structure for vibrational loading and frequencies also along with the structural loading. In this paper, numerical free-free vibration analysis has been performed for CFRP-filled honeycomb sandwich panels to analyse and predict the resonance frequencies and Eigen modes by varying the number of CFRP tubes inserted in the honeycomb and varying the honeycomb cell size. Vibrational constants like natural frequency, initial bending mode, initial lateral mode, initial torsion modes and second bending mode of CFRP-filled aluminium honeycomb were investigated. [ABSTRACT FROM AUTHOR]