Layer Formation Studies in Selective Laser Melting of Steel Powders

This paper advances the findings of the selective laser melting (SLM) of tool steel and stainless steel powders. The distinguishing feature is the melting of single layers in deep powder beds by a continuous CO2 laser. First, effect of process parameters on the surface roughness for each material is investigated. Based on these results combined with visual observation of the solidified tracks, the question is then discussed as how the processability of various type of steels is changed. The results show that surface morphology of layers is affected strongly by scan spacing, thereby giving a lower average roughness at reduced scan spacing. The effect of scan speed is also remarkable. In addition, other roughness parameters such as the peak height and skewness are found to be useful tools for evaluation of laser melted surfaces.Mechanical Engineerin

An Evaluation of Inter-Organizational Workflow Modelling Formalisms

This paper evaluates the dynamic aspects of the UML in the context of inter-organizational workflows. Two evaluation methodologies are used. The first one is ontological and is based on the BWW (Bunge-Wand-Weber) models. The second validation is based on prototyping and consists in the development of a workflow management system in the aerospace industry. Both convergent and divergent results are found from the two validations. Possible enhancements to the UML formalism are suggested from the convergent results. On the other hand, the divergent results suggest the need for a contextual specification in the BWW models. Ce travail consiste en une évaluation des aspects dynamiques du language UML dans un contexte de workflow inter-organisationnel. Le choix du language par rapport à d'autres est motivé par sa richesse grammaticale lui offrant une très bonne adaptation à ce contexte. L'évaluation se fait par une validation ontologique basée sur les modèles BWW (Bunge-Wand-Weber) et par la réalisation d'un prototype de système de gestion de workflows inter-organisationnels. À partir des résultats convergents obtenus des deux différentes analyses, des améliorations au formalisme UML sont suggérées. D'un autre coté, les analyses divergentes suggèrent une possibilité de spécifier les modèles BWW à des contextes plus particuliers tels que ceux des workflows et permettent également de suggérer d'autres améliorations possibles au langage.Ontology, Conceptual study, Prototype Validation, UML, IS development methods and tools., Ontologie, étude conceptuelle, validation du prototype, UML, méthodes et outils de développement IS

System design for periodic data production management

This research project introduces a new type of information system, the periodic data production management system, and proposes several innovative system design concepts for this application area. Periodic data production systems are common in the information industry for the production of information. These systems process large quantities of data in order to produce statistical reports in predefined intervals. The workflow of such a system is typically distributed world-wide and consists of several semi-computerized production steps which transform data packages. For example, market research companies apply these systems in order to sell marketing information over specified timelines. production of information. These systems process large quantities of data in order to produce statistical reports in predefined intervals. The workflow of such a system is typically distributed world-wide and consists of several semi-computerized production steps which transform data packages. For example, market research companies apply these systems in order to sell marketing information over specified timelines. There has been identified a lack of concepts for IT-aided management in this area. This thesis clearly defines the complex requirements of periodic data production management systems. It is shown that these systems can be defines as IT-support for planning, monitoring and controlling periodic data production processes. Their significant advantages are that information industry will be enabled to increase production performance, and to ease (and speed up) the identification of the production progress as well as the achievable optimisation potential in order to control rationalisation goals. In addition, this thesis provides solutions for he generic problem how to introduce such a management system on top of an unchangeable periodic data production system. Two promising system designs for periodic data production management are derived, analysed and compared in order to gain knowledge about appropriate concepts and this application area. Production planning systems are the metaphor models used for the so-called closely coupled approach. The metaphor model for the loosely coupled approach is project management. The latter approach is prototyped as an application in the market research industry and used as case study. Evaluation results are real-world experiences which demonstrate the extraordinary efficiency of systems based on the loosely coupled approach. Special is a scenario-based evaluation that accurately demonstrates the many improvements achievable with this approach. Main results are that production planning and process quality can vitally be improved. Finally, among other propositions, it is suggested to concentrate future work on the development of product lines for periodic data production management systems in order to increase their reuse

Application of the Fourth Industrial Revolution for High Volume Production in the Rail Car Industry

Some recent technological advances in line with the fourth industrial revolution (4IR) are rapidly transforming the industrial sector. This work explores the prospect of robotic and additive manufacturing solutions for mass production in the rail industry. It proposes a dual arm, 12-axis welding robot with advance sensors, camera, and algorithm as well as intelligent control system. The computer-aided design (CAD) of the robotic system was done in the Solidworks 2017 environment and simulated using the adaptive neuro-fuzzy interference system (ANFIS) in order to determine the kinematic motion of the robotic arm and the angles of joint. The simulation results showed the smooth motion of the robot and its suitability to carry out the welding operations for mass production of components during rail car manufacturing. In addition, the ability to fabricate several physical models directly from digital data through additive manufacturing (AM) is a key factor to ensuring rapid product development cycle. Given that AM is embedded in a digitally connected environment, flow of information as well as data processing and transmission in real time will be useful for massive turnout during mass production

Modeling and Simulation in Engineering

This book provides an open platform to establish and share knowledge developed by scholars, scientists, and engineers from all over the world, about various applications of the modeling and simulation in the design process of products, in various engineering fields. The book consists of 12 chapters arranged in two sections (3D Modeling and Virtual Prototyping), reflecting the multidimensionality of applications related to modeling and simulation. Some of the most recent modeling and simulation techniques, as well as some of the most accurate and sophisticated software in treating complex systems, are applied. All the original contributions in this book are jointed by the basic principle of a successful modeling and simulation process: as complex as necessary, and as simple as possible. The idea is to manipulate the simplifying assumptions in a way that reduces the complexity of the model (in order to make a real-time simulation), but without altering the precision of the results