Abstract: Over the past two decades it has been established that composite materials are the leading emerging materials. The natural fibres present a number of advantages over traditional synthetic fibres because of their better corrosion resistance, excellent thermo-mechanical properties and high strength to weight ratio. Also the composite materials play an important role in maintaining the eco-friendly design requirements. Among this, polymer matrix composite is one of the recent developing sectors on the composite field, because it has high strength with less density as compared to the metal matrix composite. Depending on the applications, the properties of the polymer reinforced composite are improved by modifying compositions, process of fabrication and direction of fibre etc. In this analysis the Roselle Fibre (Hibiscus Sabdariffa) is reinforced with polymer composite by wt % in the mode of compression molding. The mechanical properties of the above fabricated material were analyzed by ASTM Standards and also the characterization of polymer composites were analysed using SEM. The compressive strength and the hardness value were high as compared to other strength properties; hence it is more suitable for compressive and structural applications. The results concluded that the treated fibre with chemical reveals better compatibility with polymer matrix than that of untreated fibre.
Abstract: Abstract. Kinetic energy of a machining process is converted into heat energy. The generated heat at cutting tool and work piece interface has substantial impact on cutting tool life and quality of the work piece. On the other hand, development of advanced cutting tool materials, coatings and designs, along with a variety of strategies for lubrication, cooling and chip removal, make it possible to achieve the same or better surface quality with dry or Minimum Quantity Lubrication (MQL) machining than traditional wet machining. In addition, dry and MQL machining is more economical and environment friendly. In this work, 20 no. of experiments were carried out under dry machining conditions with different combinations of cutting speed, feed rate and depth of cut and corresponding cutting temperature and surface roughness are measured. The no. of experiments is determined through Design of Experiments (DOE). Nonlinear regression methodology is used to model the process using Response Surface Methodology (RSM). Multi-objective optimization is carried using Genetic Algorithm which ensures high productivity with good product quality.
Abstract: The flank wear and cutting power in the hot turning of Ni-Hard nickel based alloy by carbide tool was investigated in terms of cutting parameters such as cutting speed, feed rate, depth of cut and preheating temperature. Here, the Grey relational based Taguchi optimization method has carried out for optimizing the flank wear and power as output responses. Grey relational grade is obtained by Grey Relational Analysis (GRA) method and by this value the optimum setting parameter has been recognized. The experimental results show that the cutting speed is the most dominant variable and preheating temperature is the least parameter influence the responses.
Abstract: In the present work, a finite element modeling of hot turning has been carried out for predicting computationally the state variables like temperature distribution on chip surface and cutting forces in hot machining of Inconel 718. The hot turning operation has been carried out with L9 orthogonal design of experiment (DOE) with varying cutting speed, feed rate, heating temperature and constant depth of cut to analyze the responses. The model predicts the temperature distribution, cutting forces with and without heating. DEFORM 2D is applied for modeling hot turning simulation as similar as possible to the experimental result. Flow stress and input parameters should be modeled according to the actual machining conditions. The predicting results i.e. cutting forces and temperature distribution were partially validated with the experimental data.
Abstract: This work aims to provide a review of available published literature that explores the opportunities to improve the quality of fused deposit modelling (FDM) products, particularly in medical applications. The paper presents details concerning the basis of the technology, process parameter settings and their responses, and reviews the properties of common FDM engineering/bio-materials and the available methods applied for improving their performance. Based on the researches which have been reviewed, FDM technology works within a complex environment from process parameters. Thus, it can achieve good results only with the proper settings for these parameters according to the properties of the material used. Improving the polymers is essentially based on the correct selection of additive materials, which can particularly enhance the key property/properties in the matrix material. This review provides a brief insight into FDM technology, provides an idea of the process parameter settings, the available materials and ways of modifying their properties to consequently improve the quality of FDM products.
Abstract: In this paper an attempt has been made to know the effect of Fly Ash (FA) on Roller Compacted Concrete (RCC) properties like strength and abrasion resistance. The Cement was partially replaced by three kinds of replacements (20%, 40% and 60%) of class F Fly Ash. The RCC mixtures were designed to have a 28 days flexural strength of 5.0 N/mm2. The specimens were subjected to two types of abrasion resistance tests such as Contabro test and surface abrasion resistance test with rotating cutter besides Compressive and Flexural strength tests. Experimental results shows that the Cantabro loss and surface abrasion loss were increased with increase in Fly Ash content in relation with the strength of roller compacted concrete pavement at the ages from 7days to 180days compared to control mix concrete. Equations were established based on compressive strength and flexural strength which were influenced by cement replacement by Fly Ash and developed to predict abrasion resistance of FRCC at any age. Also a relationship was established between Cantabro loss and surface abrasion loss of FRCC regardless of age and percent replacement of Fly Ash.
Abstract: The main objective this study is to evaluate the permanent deformation of buton rock asphalt (BRA) modified asphalt paving mixtures using dynamic creep test so that long term deformation behavior of asphalt mixtures can be characterized. The dynamic creep test was conducted on unmodified and BRA modified asphalt mixture using UTM25 machine. Asphalt cement of C170 from a regional supplier in Western Australia was used as the base asphalt binder for unmodified asphalt mixture; and BRA modified asphalt mixtures were made by substituting the base asphalt with 10, 20, and 30% (by weight of total asphalt binder) natural binder continuing granular BRA modified binder. The granular (pellets) BRA modified binder with a diameter of 7-10 mm was produced and extracted according the Australia Standard. Crushed granite was taken from a local quarry of the region; and dense graded for both unmodified and BRA modified asphalt mixture with the nominal size of 10 mm was used. The results of this analysis showed that BRA modified had a good performance as compared with unmodified asphalt mixtures, and increase in the content modified binder to 10%, 20%, and 30% resulted in decrease of the total permanent strain.
Abstract: Reliability of centrifugal pump is considered as a main indicator to measure the capability of the pump in performing its operating envelop delivery without any premature failure. Flow induced vibration namely vane passing pressure pulsation is inherent when interaction between impeller vane wakes passes the casing volute leading edge. However, excessive excitation of hydraulic pulsation might expense the pump integrity in term of unsatisfactory unit availability, frequent equipment breakdown and high maintenance recovery cost. This paper shares a case study experienced by the authors in resolving a long outstanding reliability issue for a high energy double volute centrifugal pump through combination of rotating-stationary exit geometry modification towards an acceptable hydraulic pulsation and stable operating pump. This paper also highlights the balanced approach on the site investigation, root cause analysis and practical remedial action through industrial experiential knowledge.
Abstract: One of the most recently developed modes of propulsion is electric propulsion. The commonly used chemical propulsion systems have the advantage of a high Specific Impulse as compared to that of ion propulsion systems. However, owing to the efficacy of ion propulsion systems, it is considered the future of space exploration.Electro thermal thrusters produce thrust by using electrical fields to force hot plasma out of the nozzle with certain exit velocity. The plasma’s exit velocity and the system’s thrust capacity, as of now, are insufficient for space travel to be conducted within a reasonable time. I intend to study the possibility of improving the thruster’s performance by using an aerospike nozzle as an exit nozzle which meets the conditions required for the thruster to function appropriately. I shall be studying the plasma plume exit velocity variation with respect to the nozzles used. Also, a thermal analysis will be conducted in order to find the correct material for the nozzle.
Abstract: The interest in the localisation of wireless sensor networks has grown in recent years. A variety of machine-learning methods have been proposed in recent years to improve the optimisation of the complex behaviour of wireless networks. Network administrators have found that traditional classification algorithms may be limited with imbalanced datasets. In fact, the problem of imbalanced data learning has received particular interest. The purpose of this study was to examine design modifications to neural networks in order to address the problem of cost optimisation decisions and financial predictions. The goal was to compare four learning-based techniques using cost-sensitive neural network ensemble for multiclass imbalance data learning. The problem is formulated as a combinatorial cost optimisation in terms of minimising the cost using meta-learning classification rules for Naïve Bayes, J48, Multilayer Perceptions, and Radial Basis Function models. With these models, optimisation faults and cost evaluations for network training are considered.