PRODUCTION ENGINEERING

The high-risk exposure associated with highway construction projects needs special attention from contractors to analyze and manage their risks. They cannot be eliminated but can be minimized or transferred from one project stakeholder to another. Highway projects carry out higher risk than traditional because they entail high capital outlays and intricate site conditions. Therefore, current research aims at identifying two main risk areas that affect highway projects: company (macro) and project (micro) levels; assessing their effect on risk; and introducing a risk model (R) that facilitate this assessment procedure and prioritize these projects. Four Chinese case studies (projects A, B, C, and D) were selected to implement the designed model (R) and test its results. The R index model is developed using the analytic hierarchy process (AHP). Results show that political risk has the highest average weight of 0.5196; however, financial risk has the second highest average weight of 0.2336 in the macro level (company) areas. On the other hand, in the micro level (project), emerging technology and resource risks have the highest average weight of 0.2492 and 0.2098, respectively. The developed R model is tested, which prove its robustness in risk assessment (93%). It can also be used to sort highway construction projects based upon risk. It is an essential tool to assess the level of risk associated with the highway project under study in the bidding phase in order to take preventive actions.

Abstract The present paper outlines an experimental study to investigate the effects of cutting parameters on finish and power consumption by employing Taguchi techniques. The high speed machining of AISI 1045 using coated carbide tools was investigated. A combined tech- ...

This paper presents a solution for the photorealistic rendering of synthetic objects into dynamic real scenes, in Augmented Reality applications. In order to achieve this goal, an Image Based Lighting approach is used, where environment maps with different levels of glossiness are generated for each virtual object in the scene at every frame. Due to this, illumination effects, such as color bleeding and specular reflections, can be simulated for virtual objects in a consistent way. A unifying sampling method for the spherical harmonics transformation pass is also used. It is independent of map format and does not need to apply different weights for each sample. The developed technique is combined with an extended version of Lafortune Spatial BRDF, featuring Fresnel effect and an innovative tangent rotation parameterization. The solution is evaluated in various Augmented Reality case studies, where other features like shadowing and lens effects are also exploited.

This experimental study investigates the bioactive potential of filaments produced via hot melt extrusion (HME) and intended for fused deposition modeling (FDM) 3D printing purposes. The oleo-gum-resins from benzoin, myrrha, and olibanum in pure state and also charged with 10% of metal oxide nanoparticles, TiO 2 , P25, Cu 2 O, and MoO 3 , were characterized by ultraviolet-visible (UV-Vis) and Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray microanalysis (EDXMA), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). Disks were 3D-printed into model geometries (10 × 5 mm) and the disk-diffusion methodology was used for the evaluation of antimicrobial and antifungal activity of materials in study against the clinical isolates: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. Due to their intrinsic properties, disks containing resins in pure state mostly prevent surface-associated growth; meanwhile, disks loaded with 10% oxides prevent planktonic growth of microorganisms in the susceptibility assay. The microscopy analysis showed that part of nanoparticles was encapsulated by the biopolymeric matrix of resins, in most cases remaining disorderly dispersed over the surface of resins. Thermal analysis shows that plant resins have peculiar characteristics, with a thermal behavior similar to commercial available semicrystalline polymers, although their structure consists of a mix of organic compounds.

In order to get a deeper understanding of laser beam welding, a process model was developed at the Chair of Manufacturing Technology. It is based on the continuity equation, the equation of heat conduction and the Navier-Stokes equation. The model includes effects of Fresnel absorption, vapor pressure, surface tension, melting and evaporation enthalpy and energy loss due to evaporating material. This paper presents the results of a three-dimensional, transient finite volume simulation of a laser beam deep penetration welding process based on this model. The simulations show periodic keyhole oscillations and the complex fluid dynamics of the melt pool. A comparison of the evaporation rates calculated from the simulations and the experimentally observed process emissions shows good correlation. Furthermore, the simulations show pore formation at higher feed rates, the influence of a gap on the welding process and give an explanation for the welding behavior of zinc coated steel sheets.

This paper introduces the aim, scope and content of this special issue on mass customization. It begins by providing a background review of mass customization, which revolves around two questions: what is mass customization, and why mass customize? By focusing on these, the paper presents definitions and explanations of the different approaches to mass customization, and describes the potential reasons for and benefits of mass customization. In addition to setting the scene for the special issue, this introductory review asserts that there is a relative dearth of research on how to design and operate a manufacturing system capable of mass customizing. This is a system design or configuration issue, which involves determining the most appropriate or viable design for the available range of multiple and interdependent design variables. However, despite the strong interest in configurational research in the business and operations strategy area, there are few works that develop and propose models for understanding how to mass customize.

The evaluation and selection among the best production practices beyond the conventional linear models is, nowadays, concerned with those holistic approaches drawn toward environmental assessment in industry. Therefore, researchers need to develop an analysis that can evaluate the performance of industrial organization in the light of their environmental viewpoint. This study implemented a pilot co-integrated scheme based on an innovative in-house Holistic Assessment Performance Index for Environment (HAPI-E) industry tool while assimilating the principles of circular economy through the Eco-innovation Development and Implementation Tool (EDIT). For the latter, nine qualitative indicators were motivated and enriched the weighting criteria of the questionnaire. The decomposition of the complexity and preferences mapping was accompanied by a multi-criteria holistic hierarchical analysis methodology in order to synthesize a single index upon a need-driven scoring. This multi-criteria decision approach in industry can quantify the material and process flows, thus enhancing the existing knowledge of manipulating internal resources. The key-criteria were based on administrative, energy, water, emissions, and waste strategies. Subsequently, the HAPI-E industry tool was modeled on the food industry, being particularly focused on pasta-based industrial production. Then, the parameters of this tool were modeled, measured, and evaluated in terms of the environmental impact awareness. The magnitude of necessary improvements was unveiled, while future research orientations were discussed. The HAPI-E industry tool can be utilized as a precautionary methodology on sustainable assessment while incorporating multifaceted and quantification advantages.

Though Bangladesh is one of the largest garments manufacturingcountry in the world and there happened revolutionary changesmore than four decades ago, they couldn’tachievesustainableplat-form yet. The failure to achieve up to the requirement level for thecompetitive capabilities/manufacturing metrics is the common phe-nomenon for the manufacturers. Even there is an alarming issue thatthe manufacturers yet don’tknowhowtheyareaffected by thesefailures and also can’t measure how much they are statisticallyfit.By being motivated from manufacturer’sfailure,weworkedona manufacturing unit of a garments industry where we aggregatedmanufacturing metrics and determined how the manufacturers areaffected by the failure of these metrics. This research work will concludeby proposing few models with their mathematical and graphical expla-nation. By using these models, the manufacturers will be able todetermine their strategicfitness, security level, and associated loss/penalty.

| Focusing on the instantaneous velocities of passive joints, a new formulation approach is proposed for the instantaneous kinematics and singularity analysis of a class of three-legged parallel robots. Since only four 3 3 matrices need to be analyzed, the complexity of singularity analysis is signi cantly reduced. Using the Product-of-Exponential (POE) formula, the kinematic equations possess well-de ned algebraic structures so that the instantaneous kinematics and singularity analysis algorithms can be readily and systematically formulated. Three types of singularities, i.e, the forward, inverse, and combined singularities, have been identi ed. A uni ed condition for various singularities is proposed. Signi cant geometric conditions are also presented for identifying singularity con gurations that require simple computations.

For Citations:
Salem, H.S., 2001. Determination of the acoustic coupling factor of Biot's theory of elasticity, using in situ seismic measurements. Energy Sources, 23(10) December: 917-936. (A Scholarly Paper Published in an International Journal).

Abstract:
Besides other elastic, petrophysical, and hydrophysical parameters, the acoustic coupling factor (coupling factor or structure factor, μ) is a critical micro-geometrical parameter in the Biot’s theory of elasticity. The coupling factor exerts a
speci®c in¯uence on the mechanisms of propagation and attenuation of vibrations (seismic waves and acoustic signals) in porous media. It is a measure of the internal structure (geometry and shape of pores and pore tubes) of a porous medium, and
thus it is a good indicator of the degree of coupling between pore ¯uid and solid grains. It is unity for no coupling and in®nity for perfect coupling. In this study, the coupling factor is obtained for surface soils and shallow sediments, using compressional
wave velocity (¸p) determined from in situ seismic refraction measurements. The investigated soils and underlying sediments (aeration zone and aquifer) exhibit a general μ range of 1.22±3.19 (average = 1.82), corresponding to a general ¸f range of 134±2060 m/s (average = 1134m/s). The μ values are correlated to the
bulk modulus-shear modulus ratio (K/·) and the porosity (¿). A direct linear correlation between μ and K/· and an inverse polynomial correlation between μ and ¿ are obtained, with
coefficients of correlation of 0.91 and 0.98, respectively.
Also, various items related to the coupling factor, Biot’s theory, attenuation mechanisms, fast and slow compressional waves (®rst and second kinds), and shear waves are discussed.

Keywords:
Acoustic coupling factor (structure factor), attenuation mechanisms, Biot’s theory, compressibility, compressional and shear wave velocities, fast and slow compressional waves, frequency, in situ seismic refraction measurements,
permeability, porosity, rigidity, shallow sediments (aeration zone and aquifer), surface soils, tortuosity, viscosity.

Purpose -The purpose of this paper is to exploit student preference and propose, discuss and experimentally validate a strategy that aims to reduce time necessary to introduce tutoring of mind mapping to engineering students. Design/methodology/approach -A survey instrument was designed and used to collect student preferences about mind mapping. Preferences were linked to alternative scenarios of mind mapping deployment. Survey responses from a 100 second-year students from the Department of Production Engineering and Management were analyzed using conjoint analysis. Findings -Results indicate that an effective strategy to present mind mapping to engineering students is to explain in detail all the possible applications of mind mapping; present mind maps with different colours using both words and drawings and encourage students to use mind maps in team assignments. Originality/value -The findings of this paper provide a well documented framework in addressing mind mapping technique to engineering students. The proposed framework tries to make the best use of the available time for creativity development programs, in engineering departments. This framework may also be applied to other creativity enhancing techniques, providing solutions for incorporating creativity in engineering curricula.

"Many countries now suffer from shortage in fresh water, hence, currently 125 countries around the
world are taking advantage of desalination methods to access fresh water from brackish and seawater.
As desalination is one of the important processes for producing potable water that can be used for human
consumption, irrigation and industry. In the last decades, many researchers have been conducted to
minimize the cost of this process, and several methods have been developed. Among these methods,
distillation appears as one of the best practical and the most economical, especially for mass production
of fresh water from high saline water like seawater. On the other hand, most of the ongoing desalination
researches concentrate on large-scale plants which are suitable for mass production of fresh water. A
few researches have been conducted on small scale water distillation. This study will focus on different
distillation methods for small scale production of potable water which is suitable for domestic, small
factories, laboratories, and emergency use. This review presents various technologies available for small
scale distillation with focus on Refro-distiller systems. Consequently, the theoretical analysis to determine
the efficiency and energy costs are presented."

http://www.sciencedirect.com/science/article/pii/S1364032111003224

The metal 3-D printing market is currently dominated by high-end applications, which make it inaccessible for small and medium enterprises, fab labs, and individual makers who are interested in the ability to prototype and additively manufacture final products in metal. Recent progress led to low-cost open-source metal 3-D printers using a gas metal arc welding (GMAW)-based print head. This reduced the cost of metal 3-D printers into the range of desktop prosumer polymer 3-D printers. Consequent research established good material properties of metal 3-D printed parts with readily-available weld filler wire, reusable substrates, thermal and stress properties, toolpath planning, bead-width control, mechanical properties, and support for overhangs. These previous works showed that GMAW-based metal 3-D printing has a good adhesion between layers and is not porous inside the printed parts, but they did not proceed far enough to demonstrate applications. In this study, the utility of the GMAW approach to 3-D printing is investigated using a low-cost open-source metal 3-D printer and a converted Computer Numerical Control router machine to make useful parts over a range of applications including: fixing an existing part by adding a 3-D metal feature, creating a product using the substrate as part of the component, 3-D printing in high resolution of useful objects, near net objects, and making an integrated product using a combination of steel and polymer 3-D printing. The results show that GMAW-based 3-D printing is capable of distributed manufacturing of useful products for a wide variety of applications for sustainable development.

Over the past few years the grown global competition has enforced the manufacturing industries to upgrade their old production strategies with the modern day approaches. As a result of which, recent interest has been developed towards finding an appropriate policy that could enable them to compete with others, and facilitate them to emerge as a market winner. Keeping in mind the abovementioned facts, in this paper the authors have proposed an integrated process planning and scheduling model inheriting the salient features of outsourcing, and leagile principles to compete in the existing market scenario. The paper also proposes a model based on leagile principles, where the integrated planning management has been practiced. In the present work a scheduling problem has been considered and overall minimization of makespan has been aimed. The paper shows the relevance of both the strategies in performance enhancement of the industries, in terms of their reduced makespan. The authors have also proposed a new hybrid Enhanced Swift Converging Simulated Annealing (ESCSA) algorithm, to solve the complex real time scheduling problems. The proposed algorithm inherits the prominent features of the Genetic Algorithm (GA), Simulated Annealing (SA), and the Fuzzy Logic Controller (FLC). The ESCSA algorithm reduces the makespan significantly in less computational time and number of iterations. The efficacy of the proposed algorithm has been shown by comparing the results with GA, SA, Tabu, and hybrid Tabu-SA optimization methods.

Additive manufacturing (AM) has developed and gained popularity across the globe into a multi-billion-dollar industry that involves many materials and techniques. AM has created itself as a technology for the manufacturing of metallic parts with enhanced mechanical characteristics that are scientifically sound and commercially feasible. However, there are various challenges, from business point of view, like high machine and material costs. Considering the complexities involved, sustainable manufacturing, optimization tools, and simulation models are necessary in order to save time and costly trial and errors. Topology optimization and simulation of AM processes are commercially available and are receiving attention from scientists and industry. Thus, this chapter is designed to provide readers with a brief introduction to AM technologies with typical applications. The main objective of this chapter is to provide the current trends and innovations in the field of design for additive manufacturing (DFAM), topology optimization, and simulation technologies.

Designing appropriate quality-inspections in manufacturing processes has always been a challenge to maintain competitiveness in the market. Recent studies have been focused on the design of appropriate in-process inspection strategies for assembly processes based on probabilistic models. Despite this general interest, a practical tool allowing for the assessment of the adequacy of alternative inspection strategies is still lacking. This paper proposes a general framework to assess the effectiveness and cost of inspection strategies. In detail, defect probabilities obtained by prediction models and inspection variables are combined to define a pair of indicators for developing an inspection strategy map. Such a map acts as an analysis tool, enabling positioning assessment and benchmarking of the strategies adopted by manufacturing companies, but also as a design tool to achieve the desired targets. The approach can assist designers of manufacturing processes, and particularly low-vol...

A supervisory controller is derived for scheduling (single/multiple-part-type, reentrant) production networks. The supervisory controller is used to tune a set of lower level distributed fuzzy control modules that reduce work-in-process (WIP) and synchronize the production system's operation. The overall production-control system is viewed as a two-level surplus-based system with the overall control objective to keep the WIP and cycle time as low as possible, while maintaining quality of service by keeping backlog to acceptable levels. The production rate in each production stage is controlled to satisfy demand, avoid overloading, and eliminate machine starvation or blocking. The system's improvement is demonstrated using a set of performance measures. Extensive simulation results show that the supervisory controller, when compared with the single-level distributed fuzzy controllers reduces WIP and cycle time while keeping backlog to acceptable levels.

Lean and agile principles have grown interest in the past few decades. The industrial sectors throughout the world are upgrading to these principles to enhance their performance, since they have proven to be efficient in handling supply chains. However, the present market trend demanded a more robust strategy inheriting the salient features of both lean and agile principles. Inspired by these, the leagility principle has been emerged encapsulating, features of lean and agile. The present work proposes a leagile supply chain based model, for the manufacturing industries. The paper accentuates the various aspects of leagile supply chain modeling and implementation, and proposes a new Hybrid Chaos-based Fast Genetic Tabu Simulated Annealing (CFGTSA) algorithm to solve the complex scheduling problem prevailing in leagile environment. The proposed CFGTSA algorithm has been compared to GA, SA, TS, and Hybrid Tabu SA algorithms to reveal its efficacy in handling the complex scheduling problems.

The assessment of the performance of inspection strategies is a crucial element in the design phase of product quality inspections of manufacturing companies. The aspects that inspection designers need to consider include: (1) the typology of quality inspection, (2) the inspection variables involved, (3) the potential interaction between variables and (4) the presence of inspection errors. In particular, low-volume inspection design is critical due to the lack of historical data and the inadequacy of traditional statistical approaches. By considering these issues, this paper proposes a novel approach to support inspection designers in the prediction of offline quality inspection performance. The development of a probabilistic model based on the analysis of the possible variable interactions and inspection errors and the definition of some performance measures may successfully help designers in the early design stages of inspection process planning. The approach is supported by a pra...

Tailored Heat Treated Blanks (THTB) are blanks, which exhibit locally different material properties optimized for the succeeding sheet metal forming process. The distribution of the material properties is obtained by a local, short-term heat treatment. As a result of the optimized property gradients in the sheet metal's plain, THTB allow enhancing the forming limits significantly. The research work covered in this paper focuses on THTB made out of aluminum alloys. The article presents the microstructural mechanisms due to a short-term heat treatment as well as design principles for the heat treatment layout for THTB made out of AlMgSi alloys and ultra-fine grained (UFG) aluminum alloys produced by the Accumulative Roll Bonding process.

This paper presents a remote laboratory for industrial automation comprising different programmable logic controller (PLC) manufacturers. This facility provides an environment for remote users to learn many automation topics while using different PLCs together with several types of sensors, actuators, and industrial communication networks. The laboratory architecture that makes up the remote automation laboratory (RAL) is based on a Moodle-server master PC (MPC), which also manages the booking system of PLC benches available in the laboratory. There exist a cluster of virtual machines (VMs) running on several slave PCs (SPCs), four VMs per SPC. Each VM can manage a type of PLC bench of the automation laboratory. The MPC server balances the load of SPCs allowing the implementation and easy upgrading of the RAL offering different PLCs at the same time within the same remote interface. The remote laboratory has Internet protocol cameras providing a view of the real environment of each PLC bench to the remote user. The authentication system and management of remote users and PLC benches are made via Moodle plug-ins and hypertext preprocessor (PHP) scripts. Two external/internal routers dynamically configure the remote users' access to a particular PLC bench. RAL architecture can be applied to other e-learning areas.

Steel sandwich panels welded by laser can offer 30-50 % weight savings compared to the conventional steel structures. Helsinki University of Technology/Ship Laboratory has done active research during the past 10 years on various topics related to the laser welded steel sandwich panels. The work carried out includes development of design formulations for the ultimate and impact strength, analysis of fatigue strength for the joints, and development of solutions to improve the behaviour under fire. A number of research projects both at the national and European level have been ongoing. In the paper, a summary of the marine applications, main benefits and problem areas of the panels as well as available design tools are given. A case study for weight and cost optimisation of a hoistable cardeck is also presented proving some of the described benefits of all steel sandwich panels.

It is now generally recognized that in order to make significant advances in accident prevention, the focus of industrial firms must shift from assessing the risks of existing production and manufacturing systems to discovering technological alternatives, i.e. from the identification of problems to the identification of solutions. Encouraging the industrial firm to perform (1) an inherent safety opportunity audit (ISOA) to identify where inherently safer technology is needed, and (2) a technology options analysis (TOA) and to identify specific inherently safer options will advance the adoption of primary prevention strategies that will alter production systems so that there are less inherent safety risks. Experience gained from a methodology to encourage inherently safer production in industrial firms in the Netherlands and Greece is discussed. Successful approaches require both technological and managerial changes. Firms must have the willingness, opportunity, and the capability to change. Implications for the EU Seveso, IPPC, and EMAS Directives are also discussed.

In the present paper an experimental study to investigate the turning of hardened AISI 6150 heat treatable steel using polycrystalline boron nitride (PCBN) tools is presented. Design and analysis of computer experiments (DACE) was used to generate a comprehensive empirical description of the process characteristics. More specific, the effects of the parameters cutting speed, feed and depth of cut on the objectives tool wear, tool life, tool life volume, surface finish and process forces were modeled. A total of 157 experiments was carried out with 15 different parameter-value sets to obtain the training data for modeling the progression of the objectives versus cutting path length and width of flank wear land. Pseudo-3D surface plots are generated to visualize the effects and interactions. Unexpected effects of depth of cut on tool life were found and the validity of conclusions about the effect of cutting speed on tool wear and tool life are discussed. Moreover, qualitative explanations for some of the observed effects are presented.

The design and manufacture of fixtures and other dedicated tooling for positioning of workpieces are among the major cost drivers in product industrialization. This has spurred research and commercial interest towards other fixturing solutions like reconfigurable fixtures, with the ability to be changed, or ''reconfigured'', to suit different parts and products. When reconfiguring, the product interface not only has to be moved but moved to a desired position and orientation. Several different approaches have been used to move and position these devices, all with their own advantages and disadvantages. This article presents different methods used to position and reconfigure flexible fixture devices using a parallel kinematic device as a case. Discussing the different ways to reconfigure a flexible device, the article aims to arrange the techniques according to their key features.

To determine the possibility of using sugar- cane bagasse (SCB)and ground nut shell particulate(GNSP) waste as reinforcing ?ller in the thermo plastic polymer matrix, SCB&GNSP-reinforced polypropylene (PP) composites were prepared. The PP and SCB and GNSP composites were prepared by the extrusion of PP and GNSP with 5, 10, 15, and 20 wt % of SCB and GNSP with 3,6,9 and 12% filler in a co rotating twin screw extruder.. The extruded strands were cut into pellets and injection molded to make test specimens. These specimens were tested for physical and mechanical properties such as tensile, flexural, Izod impact strength shore D hardness and water absorption. It was found that the Tensile strength increased from 29.06 to 31.38 MPa, Flexural strength increased from 28.62 to 43.56 MPa, Izod impact strength decreased from 35.11 to 30.93 J/m, and Shore D Hardness increased from 64.88 to 77.89, with increase in filler loading from 5 to 20% in the PP matrix. The decrease in Izod Impact strength and elongation with addition of SCB & GNSP filler to PP matrix follows the general trend of filler effects on polymer matrix. However, the main purpose of this work was to study the effect of SCB & GNSP waste on the mechanical properties of the PP Composites. The SCB and GNSP waste can be used as filler in the PP composites, which will reduce cost and give environmental benefits.

Agility, reactivity and sustainability are key to cope with today's dynamic markets, as has been broadly recognized. Depending on the source, manufacturing systems are required to be modular, hierarchical or heterarchical, distributed, flexible or reconfigurable; companies can be represented using the Bionic, Fractal and Holonic concepts.

Laser powder bed fusion additive manufacturing is used for demanding applications in industries such as aerospace. However, machine-specific, optimized process conditions and parameters are required to assure consistent part quality. In addition, differences in supplied powder can cause variation in the mechanical properties of the final parts. In this paper, the variability in mechanical properties of 316L stainless steel produced with two different laser powder bed fusion machines from two different powder batches was studied by producing an identical set of tensile and impact toughness test specimens. The samples were subjected to stress-relieving, solution annealing and hot isostatic pressing to assess the effectiveness of standardized heat-treatments in reducing variation in the mechanical properties of the built parts. Porosity, microstructure, tensile properties, and impact toughness of the specimens were measured to study the effect of changing the material, machine, and heat treatment. The maximum differences observed between the studied machine-powder combinations were approximately 7% for tensile properties and approximately 20% for impact toughness. HIP reduced the variability in all other studied properties except elongation. All the specimens fulfil the minimum requirements set in ASTM F3184-16 for AM 316L.

To counteract increasing competition and satisfy evolving customers’ needs, many firms are changing the positioning of their offering, from being product-based into service-based. Despite the increasing relevance of this shift, it is still unclear if this choice has a differential impact on customer perceived value.

Therefore the purpose of this paper is to analyze customer perceived value for a firm’s offering being positioned either as service-based or product-based. An experiment was conducted using stimuli from two different product categories (hearing aids and bicycles) and measuring customers perceived value through the PERVAL scale’s four dimensions (quality value, emotional value, price value, social value).

The results show that presenting the product as service-based instead of good-based can enhance customer perceived value (in particular: quality, emotional and social value), but only if customers are not familiar with the product.

This paper presents a study of the effect of process parameters on production accuracy obtained through ultrasonic drilling of holes in alumina based ceramics using silicon carbide abrasive. Production accuracy in ultrasonic drilling involves both dimensional accuracy (hole oversize) and form accuracy (out-ofroundness and conicity). The parameters considered are workpiece material, tool material, grit size of the abrasive, power rating and slurry concentration. Taguchi's optimization approach is used to obtain the optimal parameters. The significant parameters are also identified and their effect on oversize, out-of-roundness and conicity are studied. The results obtained are validated by conducting the confirmation experiments.

The occurrence of tool vibrations in the micromilling process is undesirable because of its negative influence on the quality of microstructures. Due to the small dimensions of the undeformed chip parameter, the influence of the cutting edge on the chip formation and on the regenerative effect seems to be larger than in macrodimensions. Within this paper the results of an experimental investigation with micro end-milling cutters (d = 1 mm) are presented. Additionally, the influences of the cutting edge radius, the corner radius, and the feed per tooth on the tool vibration trajectories, the process forces, and chatter and its causes are discussed.

In the last years, hard-to-machine nickel-based alloys have been widely employed in the aerospace industry for their properties of high strength, excellent resistance to corrosion and oxidation, and long creep life at elevated temperatures. As the machinability of these materials is quite low due to high cutting forces, high temperature development and strong work hardening, during machining the cutting tool conditions tend to rapidly deteriorate. Thus, tool health monitoring systems are highly desired to improve tool life and increase productivity. This research work focuses on tool wear estimation during turning of Inconel 718 using wavelet packet transform (WPT) signal analysis and machine learning paradigms. A multiple sensor monitoring system, based on the detection of cutting force, acoustic emission and vibration acceleration signals, was employed during experimental turning trials. The detected sensor signals were subjected to WPT decomposition to extract diverse signal feat...

Today a large number of microstructures are already employed as separate components or as constituents of larger modules in a broad spectrum of production in medical technology, optics, biotechnology, mechatronics, fluidics, (micro)-forming and tool construction. Current research activities are directed towards the downscaling of manufacturing procedures or the formation of complex process chains for the manufacture of micro workpieces. The

Additive manufacturing (AM) is expanding the manufacturing capabilities. However, quality of AM produced parts is dependent on a number of machine, geometry and process parameters. The variability of these parameters affects the manufacturing drastically and therefore standardized processes and harmonized methodologies need to be developed to characterize the technology for end use applications and enable the technology for manufacturing. This research proposes a composite methodology integrating Taguchi Design of Experiments, multi-objective optimization and statistical process control, to optimize the manufacturing process and fulfil multiple requirements imposed to an arbitrary geometry. The proposed methodology aims to characterize AM technology depending upon manufacturing process variables as well as to perform a comparative assessment of three AM technologies (Selective Laser Sintering, Laser Stereolithography and Polyjet). Results indicate that only one machine, laser-based Stereolithography, was feasible to fulfil simultaneously macro and micro level geometrical requirements but mechanical properties were not at required level. Future research will study a single AM system at the time to characterize AM machine technical capabilities and stimulate pre-normative initiatives of the technology for end use applications.

Manufacturing companies from high-wage countries must focus on future markets and products to remain competitive and to ensure long-term success. In a dynamic, global environment it is necessary to further improve the underlying production technologies and methodologies to achieve sustainable competitive advantages. Thus, a technology roadmap for advanced production technologies and approaches has been developed. The roadmap provides an overview

Computer numerical control (CNC) machine
tools are automated devices capable of generating complicated
and intricate product shapes in shorter time.
Selection of the best CNC machine tool is a critical,
complex and time-consuming task due to availability of a
wide range of alternatives and conflicting nature of several
evaluation criteria. Although, the past researchers had
attempted to select the appropriate machining centres using
different knowledge-based systems, mathematical models
and multi-criteria decision-making methods, none of those
approaches has given due importance to the voice of customers.
The aforesaid limitation can be overcome using
quality function deployment (QFD) technique, which is a
systematic approach for integrating customers’ needs and
designing the product to meet those needs first time and
every time. In this paper, the adopted QFD-based
methodology helps in selecting CNC turning centres for a
manufacturing organization, providing due importance to
the voice of customers to meet their requirements. An
expert system based on QFD technique is developed in
Visual BASIC 6.0 to automate the CNC turning centre
selection procedure for different production plans. Three
illustrative examples are demonstrated to explain the realtime
applicability of the developed expert system.

A key to solving the discrepancies of deterministic and static assembly sequences at manual work places is seen in situation-oriented and cognitive methodologies in assembly. These provide means for efficient and ergonomically feasible worker guidance. An accurate and detailed technique of adjusting the instructional content is seen as a prerequisite. In this context the authors present factors for a multi-dimensional measurement of the degree of detail and complexity of manual assembly tasks. It extends the concept and application of common systems of predetermined times. It includes dimensions of actual human performance and attention allocation, as well as learning effects based on the product and its reference levels. It is assumed that identifying global attributes that contribute to assembly difficulty will provide means for predicting assembly complexity more effectively.

The main objective of this research work is to investigate size effects by downscaling the twist drilling process into the micro range (diameter: d = 50 lm to 1 mm). Therefore, experimental micro drilling tests in steel AISI 1045 (normalized and full-annealed) are performed with different cutting conditions (drill diameter, feed, cutting speed) and compared with data obtained from conventional drilling. Various size effects and its significant influence on the micro cutting process are characterized with help of the experimental results. Additionally, the formula of Victor-Kienzle is adjusted to model the feed force in micro drilling operations.

The COVID-19 pandemic has caused a surge of demand for medical supplies and spare parts, which has put pressure on the manufacturing sector. As a result, 3D printing communities and companies are currently operating to ease the breakdown in the medical supply chain. If no parts are available, 3D printing can potentially be used to produce time-critical parts on demand such as nasal swabs, face shields, respirators, and spares for ventilators. A structured search using online sources and feedback from key experts in the 3D printing area was applied to highlight critical issues and to suggest potential solutions. The prescribed outcomes were estimated in terms of cost and productivity at a small and large scale. This study analyzes the number and costs of parts that can be manufactured with a single machine within 24 h. It extrapolates this potential with the number of identical 3D printers in the world to estimate the global potential that can help practitioners, frontline workers, and those most vulnerable during the pandemic. It also proposes alternative 3D printing processes and materials that can be applicable. This new unregulated supply chain has also opened new questions concerning medical certification and Intellectual property rights (IPR). There is also a pressing need to develop new standards for 3D printing of medical parts for the current pandemic, and to ensure better national resilience.