Bio: Gerald Byrne is an academic researcher from University College Dublin. The author has contributed to research in topics: Chemical-mechanical planarization & Machining. The author has an hindex of 8, co-authored 16 publications receiving 357 citations.
TL;DR: In this article, the formation of saw-tooth chips is attributed to the operation of thermally softened micro-shear zones, which, it is suggested, are a precursor to adiabatic shear initiation.
Abstract: The formation of saw-tooth chips is one of the primary characteristics in the machining of hardened steels with geometrically defined cutting tools. Catastrophic failure within the primary shear zone during saw-tooth chip formation is usually attributed to either cyclic crack initiation and propagation or to the occurrence of a thermo-plastic instability. The results presented here show that the primary instability resulting in the formation of saw-tooth chips is initiation of adiabatic shear at the tool tip and propagation partway towards the free surface. Depending on the work material hardness and cutting conditions, catastrophic failure within the upper region of the primary shear zone occurs through either ductile fracture or large strain plastic deformation. Prior to the onset of chip segmentation, which occurs with increases in work material hardness and cutting speed, there is a transition in the morphology of the free surface of continuous chips, from the familiar lamellar structure to what has been termed a fold-type structure. This transition is attributed to the operation of thermally softened micro-shear zones, which, it is suggested, are a precursor to adiabatic shear initiation.
TL;DR: In this article, a new emerging frontier in the evolution of the digitalisation and the 4th industrial revolution (Industry 4.0) is considered to be that of biologicalisation in manufacturing.
Abstract: A new emerging frontier in the evolution of the digitalisation and the 4th industrial revolution (Industry 4.0) is considered to be that of “Biologicalisation in Manufacturing”. This has been defined by the authors to be “The use and integration of biological and bio-inspired principles, materials, functions, structures and resources for intelligent and sustainable manufacturing technologies and systems with the aim of achieving their full potential.” In this White Paper, detailed consideration is given to the meaning and implications of “Biologicalisation” from the perspective of the design, function and operation of products, manufacturing processes, manufacturing systems, supply chains and organisations. The drivers and influencing factors are also reviewed in detail and in the context of significant developments in materials science and engineering. The paper attempts to test the hypothesis of this topic as a breaking new frontier and to provide a vision for the development of manufacturing science and technology from the perspective of incorporating inspiration from biological systems. Seven recommendations are delivered aimed at policy makers, at funding agencies, at the manufacturing research community and at those industries involved in the development of next generation manufacturing technology and systems. It is concluded that it is valid to argue that Biologicalisation in Manufacturing truly represents a new and breaking frontier of digitalisation and Industry 4.0 and that the market potential is very strong. It is evident that extensive research and development is required in order to maximise on the benefits of a biological transformation.
TL;DR: Evidence is shown to suggest that the quality control processes used to manufacture knives fail to produce consistently uniform blade points in knives that are nominally identical, and that the penetration forces associated with Nominally identical knives can vary by as much as 100%.
Abstract: This paper describes the development and use of a biaxial measurement device to analyse the mechanics of knife stabbings In medicolegal situations it is typical to describe the consequences of a stabbing incident in relative terms that are qualitative and descriptive without being numerically quantitative Here, the mechanical variables involved in the possible range of knife-tissue penetration events are considered so as to determine the necessary parameters that would need to be controlled in a measurement device These include knife geometry, in-plane mechanical stress state of skin, angle and speed of knife penetration, and underlying fascia such as muscle or cartilage Four commonly available household knives with different geometries were used: the blade tips in all cases were single-edged, double-sided and without serrations Appropriate synthetic materials were used to simulate the response of skin, fat and cartilage, namely polyurethane, compliant foam and ballistic soap, respectively The force and energy applied by the blade of the knife and the out of plane displacement of the skin were all used successfully to identify the occurrence of skin penetration The skin tension is shown to have a direct effect on both the force and energy for knife penetration and the depth of out of plane displacement of the skin simulant prior to penetration: larger levels of in-plane tension in the skin are associated with lower penetration forces, energies and displacements Less force and energy are also required to puncture the skin when the plane of the blade is parallel to a direction of greater skin tension than when perpendicular This is consistent with the observed behaviour when cutting biological skin: less force is required to cut parallel to the Langer lines than perpendicularly and less force is required to cut when the skin is under a greater level of tension Finally, and perhaps somewhat surprisingly, evidence is shown to suggest that the quality control processes used to manufacture knives fail to produce consistently uniform blade points in knives that are nominally identical The consequences of this are that the penetration forces associated with nominally identical knives can vary by as much as 100%
••01 Oct 2016
TL;DR: In this paper, the authors discuss the latest developments in the area of Internet of Things (IoT) technologies with regard to their potential application in the manufacturing sector and logistics, and a series of enabling technologies are identified and described in relation to how they may foster the further development and wider adoption of IoT technologies.
Abstract: This paper discusses the latest developments in the area of Internet of Things (IoT) technologies with regard to their potential application in the manufacturing sector and logistics. A series of enabling technologies are identified and described in relation to how they may foster the further development and wider adoption of IoT technologies. A number of potential application areas together with some early prototype IoT-based developments are reviewed and the major challenges to be addressed in the near future are listed. IoT technologies may play a very important role towards improving the performance and flexibility of manufacturing operations and logistics processes and may also enable the more efficient design and lifecycle management of products.
TL;DR: In this article, an electromechanical model is used to relate the electrical and mechanical domains, comprising the PZT stacks and the flexure mechanism, with the dynamic characteristics of the latter represented by a multiple degree-of-freedom dynamic model.
Abstract: The piezoelectric flextensional actuator investigated in this paper comprises three pre-stressed piezoceramic lead zirconate titanate (PZT) stacks and an external, flexure-hinged, mechanical amplifier configuration. An electromechanical model is used to relate the electrical and mechanical domains, comprising the PZT stacks and the flexure mechanism, with the dynamic characteristics of the latter represented by a multiple degree-of-freedom dynamic model. The Maxwell resistive capacitive model is used to describe the nonlinear relationship between charge and voltage within the PZT stacks. The actuator model parameters and the electromechanical couplings of the PZT stacks, which describe the energy transfer between the electrical and mechanical domains, are experimentally identified without disassembling the embedded piezoceramic stacks. To verify the electromechanical model, displacement and frequency experiments are performed. There was good agreement between modelled and experimental results, with less than 1.5% displacement error. This work outlines a general process by which other pre-stressed piezoelectric flextensional actuators can be characterized, modelled and identified in a non-destructive way.
TL;DR: An intertwined supply network (ISN) is an entirety of interconnected supply chains (SC) which, in their integrity secure the provision of society and markets with goods and services.
Abstract: An intertwined supply network (ISN) is an entirety of interconnected supply chains (SC) which, in their integrity secure the provision of society and markets with goods and services. The ISNs are o...
TL;DR: The histological investigation concluded that there is a definite correlation between the orientation of the Langer lines and the preferred orientation of collagen fibres in the dermis and the data obtained will provide essential information for those wishing to model the skin using a structural constitutive model.
Abstract: The mechanical properties of skin are important for a number of applications including surgery, dermatology, impact biomechanics and forensic science. In this study, we have investigated the influence of location and orientation on the deformation characteristics of 56 samples of excised human skin. Uniaxial tensile tests were carried out at a strain rate of 0.012 s(-1) on skin from the back. Digital Image Correlation was used for 2D strain measurement and a histological examination of the dermis was also performed. The mean ultimate tensile strength (UTS) was 21.6±8.4 MPa, the mean failure strain 54%±17%, the mean initial slope 1.18±0.88 MPa, the mean elastic modulus 83.3±34.9 MPa and the mean strain energy was 3.6±1.6 MJ/m(3). A multivariate analysis of variance has shown that these mechanical properties of skin are dependent upon the orientation of the Langer lines (P<0.0001-P=0.046). The location of specimens on the back was also found to have a significant effect on the UTS (P=0.0002), the elastic modulus (P=0.001) and the strain energy (P=0.0052). The histological investigation concluded that there is a definite correlation between the orientation of the Langer lines and the preferred orientation of collagen fibres in the dermis (P<0.001). The data obtained in this study will provide essential information for those wishing to model the skin using a structural constitutive model.
TL;DR: The VSC model can help firms in guiding their decisions on recovery and re-building of their SCs after global, long-term crises such as the COVID-19 pandemic and can be of value for decision-makers to design SCs that can react adaptively to both positive changes and negative changes.
Abstract: Viability is the ability of a supply chain (SC) to maintain itself and survive in a changing environment through a redesign of structures and replanning of performance with long-term impacts. In this paper, we theorize a new notion-the viable supply chain (VSC). In our approach, viability is considered as an underlying SC property spanning three perspectives, i.e., agility, resilience, and sustainability. The principal ideas of the VSC model are adaptable structural SC designs for supply-demand allocations and, most importantly, establishment and control of adaptive mechanisms for transitions between the structural designs. Further, we demonstrate how the VSC components can be categorized across organizational, informational, process-functional, technological, and financial structures. Moreover, our study offers a VSC framework within an SC ecosystem. We discuss the relations between resilience and viability. Through the lens and guidance of dynamic systems theory, we illustrate the VSC model at the technical level. The VSC model can be of value for decision-makers to design SCs that can react adaptively to both positive changes (i.e., the agility angle) and be able to absorb negative disturbances, recover and survive during short-term disruptions and long-term, global shocks with societal and economical transformations (i.e., the resilience and sustainability angles). The VSC model can help firms in guiding their decisions on recovery and re-building of their SCs after global, long-term crises such as the COVID-19 pandemic. We emphasize that resilience is the central perspective in the VSC guaranteeing viability of the SCs of the future. Emerging directions in VSC research are discussed.
TL;DR: In this article, a comprehensive study on various factors, that affects the sustainable supply chain were analyzed and the results recorded, based on the review, a framework for assessing the readiness of supply chain organization from various perspectives has been proposed to meet the requirements of the fourth Industrial Revolution.
Abstract: Supply Chain organizations in the present global environment operate in market that is increasingly complex and dynamic in nature. Sustainable supply chain becomes inevitable to meet the aggressive change in the customer requirements. Based on the reviews, it is revealed that manufacturing companies need to speed up in shifting the focus towards sustainability and make use of technology like ‘Internet of Things’ (IoT) to meet the organization’s goal. The objective of this research paper is to review the various aspects of SCM, ERP, IoT and Industry 4.0 and explore the potential opportunities available in IoT embedded sustainable supply chain for Industry 4.0 transformation. In this review, a comprehensive study on various factors, that affects the sustainable supply chain were analyzed and the results recorded. Based on the review, a framework for assessing the readiness of supply chain organization from various perspectives has been proposed to meet the requirements of the fourth Industrial Revolution. The conceptual framework model has been formulated from five important perspectives of supply chain management namely Business, Technology, Sustainable Development, Collaboration and Management Strategy. This study furnishes the criteria that can be assessed by companies to realize the readiness for industry 4.0 transformation.
01 Jun 2015
TL;DR: Project-5-Mapping Existing Research Output Focused on Higher Education Teaching and Learning in Ireland 1990-2015 is presented.
Abstract: Title Mapping Existing Research Output Focused on Higher Education Teaching and Learning in Ireland 1990-2015 Authors(s) O'Sullivan, Sara; Gibney, Amanda; Guerin, Suzanne; Staunton, Michael; Kalaitzake, Manolis Publication date 2015-06 Publisher National Forum Link to online version http://www.teachingandlearning.ie/wp-content/uploads/2015/07/Project-5-Mapping-Existing-Research-Output.pdf Item record/more information http://hdl.handle.net/10197/6860