Laurent Deshayes

AN ONTOLOGY ARCHITECTURE FOR STANDARDS INTEGRATION AND CONFORMANCE IN MANUFACTURING

Standards reflect consensus on the semantics of terms. When used to communicate, whether between people or software systems, standards ensure the communication is correct. Different standards have different semantics for the same terms and express common concepts using different terms and in different ways. Communication between software systems based on different standards is sometimes difficult to achieve. Standards integration concerns the explicit representation of the overlapping sets of concepts in standards and the differences in their semantics to ensure that these standards are used consistently together. This in turn enables software that is based on integrated standards to interoperate, reducing the cost of software integration. Standards conformance determines whether the interpretation of the standardized terms used by software applications is consistent with semantics given by the standards. This paper proposes a general architecture to design ontologies for standards integration and conformance in manufacturing engineering. The ontology architecture is divided into four levels: vendor, standards, domain, and core. Manufacturing turning tools are used as a case study to illustrate the approach. Finally this paper offers some short examples of first order logic propositions.

Smart machining systems: issues and research trends

Smart Machining Systems (SMS) are an important part of Life Cycle Engineering (LCE) since its capabilities include: producing the first and every product correct; improving the response of the production system to changes in demand (just in time); realizing rapid manufacturing; and, providing data on an as needed basis. Thereby, SMS improve the performance of production systems and reduce production costs. In addition, an SMS not only has to improve a particular machining process, but it also has to determine the best optimized solution to produce the part faster, better, at lower cost, and with a minimum impact on the environment. In addition, new software tools are required to facilitate the improvement of a machining system, characterized by a high level of expertise or heuristic methods. A global approach requires integrating knowledge/information about the product design, production equipment, and machining process. This paper first discusses the main characteristics and components that are envisioned to be part of SMS. Then, uncertainties associated with models and data and the optimization tasks in SMS are discussed. Robust Optimization is an approach for coping with such uncertainties in SMS. Current use of machining models by production engineers and associated problems are discussed. Finally, the paper discusses interoperability needs for integrating SMS into the product life cycle, as well as the need for knowledge-based systems. The paper ends with a description of future research trends and work plans.

Serrated Chip Morphology and Comparison with Finite Element Simulations

ABSTRACT The complexity of chip formation in machining processes stems from the confluence of several physical phenomena - mechanical, thermal, and chemical - occurring at very high strain rate. The prediction of chip morphology depends on a fundamental understanding of these phenomena and is of industrial importance for cutting force prediction and surface integrity control. Within this framework, our paper focuses on the modelling of serrated-chip formation (saw-tooth shape chip) and on the physical phenomena accompanying the serrated-chip formation according to the variation of feed rate. In the first part, bibliography review and experimental study on chip formation is made. The experimental study, based on metallographic analysis of chip morphology, focuses on the machining of an American Iron and Steel Institute (AISI) 4340 steel alloy work material. The second part of the paper deals with the FEM model to simulate cutting processes using the Abaqus explicit code and Third Wave Systems Advantedge software. The simulations utilize plasticity models for material behaviour and damage to predict chip morphology. The third section proposes a comparison of simulations results with experimental observations. Experimental results support the results of the simulations for various cutting parameters. We end the paper with some concluding remarks.

Robust Optimization for Smart Machining Systems: An Enabler for Agile Manufacturing

This paper reports our efforts towards developing a mathematical and information framework for optimization of machining processes within a Smart Machining System (SMS). An SMS uses diverse integrated technologies that enable an enterprise to: (1) produce the first and every product correct; (2) improve the response of the production system to changes in demand (just in time); (3) realize rapid and agile manufacturing; and (4) provide data to the rest of the enterprise as needed. Optimization of machining processes is an important component of an SMS and contributes to realizing these capabilities. Based on a prototype, we demonstrate the concepts for robust optimization within an SMS and develop requirements and challenges for robust optimization in an SMS.

A Failure Analysis of an Experimental AlMgB14 Cutting Tool

A recently developed ultra-hard boride-based material, AlMgB14, has been fabricated into a standard cutting tool geometry (TPG-222) and tested using single-point turning of Ti-6Al-4V. The initial testing was conducted to compare this new cutting tool’s performance relative to a WC-Co cutting tool. During the tests the boride-based inserts suffered catastrophic failure for a wide range of cutting conditions, and so a failure analysis was conducted on these inserts.

Mechanical and Thermal Behavior for Machining Ti-6Al-4V With AlMgB14 and WC-Co Tools

Many tool materials dissolve, diffuse, and/or react with titanium due to the high temperatures at the tool/workpiece interface. Potential next generation tool materials that would improve the machining of titanium and eliminate the contamination of the work piece are being developed. One material, Aluminum Boride (AlMgB14 ), is the basis of the research presented in this paper. Specimens of the newly developed tool material, AlMgB14 were fabricated into a standard tool geometry. This tool material was compared with a standard WC-Co tool material to machine a Ti-6Al-4V workpiece. During orthogonal cutting, thermal and force measurements were made using both types of tool material. The measurements are compared with finite element simulations. This paper shows higher chip temperatures are obtained with AlMgB14 and this material demonstrates benefits associated with tool thermal conductivity, including improved chip segmentation, smaller cutting and thrust forces. Nevertheless, a weakness of AlMgB14 is its fracture toughness, which needs to be improved for better performance in an industrial environment.© 2005 ASME