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Due to the full integration of CAD systems into modern product development and engineering, the competency to create usable geometric models has become an essential requirement for current CAD users. To avoid serious repercussions for future engineering labor, the focus of CAD education needs to be raised from the teaching of knowledge that is merely aimed at operating a system, to the development of basic strategic knowledge. From a pedagogical point of view, this situation represents a challenging task that requires new, innovative teaching methodologies. These new methodologies must facilitate the development of know-how and cognitive ability to organize domain knowledge within a holistic mental model allowing for accurate perception of the significance of circumstances and the possible consequences of actions. In this paper a new direction for CAD education is presented, based on the integration of traditional teaching methods with an educational approach based on negative knowledge. Analysis of first empirical results of this newly developed and implemented approach showed promising results. Improvements were observed in a better understanding of issues related to the usability of CAD models and an increased capability to recognize critical modeling situations and thus prevent the mistakes typically made by novices. Also, successful autonomous attempts could be observed of recovery from situations caused either by an accumulation of small mistakes or by severe modeling errors, which usually require remedial intervention by academic supervisors.Highlights Introduction of a novel framework for supporting competency development within the field of higher education for hybrid geometric modeling. Integration of traditional teaching methods with an educational approach based on negative knowledge. Currently observed improvements of learning outcomes include a better understanding of issues related to the usability of CAD models. Increased capability to recognize critical modeling situations and thus prevent the mistakes typically made by novices.

With the rising importance of CAD models for product development and the recent strong promotion of hybrid geometric modeling from within the industry, the focus of teaching methods in current CAD education, as practiced in most institutions of higher education, needs to be reconsidered. From a pedagogical point of view, this situation represents a challenge, as it requires new, innovative teaching methodologies which advance the development of competency going beyond basic domain knowledge and skills limited to operating a CAD system. In this paper, a new and innovative direction for CAD education is offered, which is based on the integration of traditional teaching methods with an educational approach using negative knowledge. Central aspects of framework development and concept translation are presented together with promising results obtained through a multi-method oriented empirical study of this newly developed and now fully implemented approach.

Purpose – High pressure die casting is a widely used industrial process to manufacture complex-shaped products in light alloys. Virtual prototyping techniques, especially numeric-based simulations of the casting process, allow the die filling process to be evaluated and help faster optimization of the gating system, which is the most critical element of the mould. The purpose of this paper is to present a four step approach to design optimal moulds taking advantage of the simulation tools. Design/methodology/approach – No formalized method to design an optimal gating system is available yet and the majority of the studies aim to optimize existing geometries or to choose from alternative solutions. Rather than optimizing the geometries of predefined designs by running attempt trials, the proposed approach defines a procedure to position cavities, gating systems and, finally, to determine the whole mould geometry. Findings – The approach is demonstrated through three different industrial applications. The design of a six-cavity mould for gas cooking burners is reported at first. Then, two test cases, a cup and a radiator, are reported for showing different arrangements of the gating system. The reached quality of the mould design has been assessed using metallographic analyses of the casts. Originality/value – The design of a mould is strictly correlated to its product and mainly based on a trial-and-error approach. Numerical simulations offer a powerful and not expensive way to study the effectiveness of different die designs and filling processes. The paper proposes a structured approach for the definition of the gating system. It ultimately leads to improvements in both product quality and process productivity, including more effective control of the die filling and die thermal performance.

The use of virtual prototypes in product development has been proliferating rapidly in the last two decades. New computational methods and tools have been developed to generate virtual prototypes for various engineering analysis, simulation and optimization tasks. Virtual prototypes can represent several aspects of products, including among others; geometric and structural properties, physical operations and behavior, and production, use and maintenance processes. The development of methods and tools is continuously expanding towards new application domains and users are getting more and more involved in testing virtual prototypes of products. Numerical computations are getting more accurate and reliable. Through the analyses and simulations of virtual prototypes, design engineers are now able to ensure that a product will possess exactly the desired functions, properties, behaviour, quality and cost. In the hope of new opportunities, multi-disciplinary, transdisciplinary and trans-domain knowledge transformation has become one of the central topics of scientific research in virtual prototyping. Typical examples of multiand transdomain knowledge transformation are based on: (i) generalization of methods (e.g., design of computer experiments), (ii) introduction of novel technologies to enable simulation of complex physical phenomena (e.g., multiple contact in ropes), (iii) development of multi-physics solvers that facilitate the analysis of multi-faceted systems, and (iv) integration of interactive virtual testing of concepts into the product validation processes. In the field of computer-aided engineering analysis and simulation, multi-disciplinary transformation of knowledge involves the following activities: (1) identification of opportunities for integration of knowledge of multiple disciplines, (2) exporting knowledge among various mono-disciplinary applications, and (3) combining monodisciplinary knowledge to enable multi-disciplinary simulation and optimization. It has to be noted that the mono-disciplinary analysis and simulation methods are also further refined. The new methods and tools allow us to model, simulate and optimize the operations of complex engineering systems, such as internal combustion engines, industrial process plants, multi-product packaging systems, smart robotic systems, etc. In this Special Issue, we provide examples of multi-, and trans-disciplinary and trans-domain knowledge and numerical computation technology transfer in the field of engineering analysis and simulation, in addition to presenting results of the efforts towards enhancing mono-disciplinary analysis and simulation approaches. Furthermore, we intend to show that the methods and tools proposed by the contributing authors are not only significant from an academic point of view, but are also valuable for the industrial practice. The selected papers cover a wide range of application fields, indicating the importance of multi-domain knowledge enrichment and transfer. Originally, the papers were presented at the Ninth International Symposium on Tools and Methods of Competitive Engineering (TMCE 2010), that was held in Ancona, Italy, from 12 until 16 April, 2010. The TMCE 2010 Symposium was jointly organized by the Universita Politecnica delle Marche, Italy, and the Delft University of Technology, the Netherlands. The papers have been thematically arranged in this special issue. The first five papers are representative examples of knowledge enrichment. They focus on monoZ. Rusak (&) I. Horvath Delft University of Technology, Delft, The Netherlands e-mail: Z.Rusak@tudelft.nl

Traditional computer-aided design (CAD) education in mechanical engineering still remains a major challenge today both in industrial settings and in academia. As in many other CAD-related engineering disciplines there are several shortcomings to be surmounted in the dissemination and development of procedural knowledge and skills in the form of know-how related to the operation of CAD systems. Unfortunately current educational philosophy does not offer a pedagogy providing sufficient strategic knowledge and understanding to enable students to use CAD systems as intended – that is as knowledge-intensive design and communication tools to properly develop and convey design intent. However apart from knowing what to do there is another important aspect to strategic knowledge which is frequently over-looked and ignored in research today and that is knowing how to avoid serious mistakes. This is a central quality of professional expertise which is commonly referred to in the literature as negative knowl...

3D optical scanning systems are used more and more for quality control purposes. The effective utilization of such systems needs an efficient virtual planning of the product acquisition viewpoints. Literature shows how 3D CAD product models can be used as reference in order to manage the verification process and as a basis for the computation of the optimal viewpoints. However, in the mechanical field, a variety of inspection tasks is experienced by engineers involved in the quality control process: GD&T verification, production phases control such as sheet metal cutting, evaluation of aesthetic appearance of parts, global shape deformation measurement and specific point deviations assessment. This leads to the necessity of flexible view planning approaches which adapt to the specificity of the required inspection task. The present work targets the development of a comprehensive view planning approach in which several algorithmic options are triggered by the product features to be inspected. Algorithms have been implemented in a prototypal software system which has been experimented as an off-line application to provide inputs to a multi-axis degree of freedom robot arm mounting an optical 3D scanner. Two test cases from die casting and automotive fields are presented. They show the computation of acquisition poses in a suitable sequence and efficiency in the obtained results.

Mechanical product quality is strongly influenced by the respect of Geometrical Tolerances (GT). On the other hand, competitiveness forces companies to improve their productivity making the tolerance verification process faster and faster and more flexible. Component control by 3D full field optical digitizing systems and specific CAD-based (Computer Aided Design) inspection software tools are important steps forward for the achievement of the above-mentioned goals. However, the adoption of these solutions in industry is minimal. This may be due both to technological factors, i.e. poor systems usability, and organizing factors, i.e. clear separation between design department and quality control department. In this context, our research aims at developing a new easy to use CAD-based tool for simulating, driving and optimizing the GT inspection process. Once a component has been digitized, the developed software system automatically realizes the tolerances virtual control. Hence, the designer can prescribe tolerances, pilot the measurement system and verify the component conformity. The implemented tool is based on Full of Information (FoI) CAD models, which contain tolerance data, linked to a knowledge database, where measurement strategies and verification rules are stored. A computation engine calculates the measurement paths and performs the tolerances verification. The prototypal system has been tested on different real cases. Experimental results showed high performances in terms of timesaving and robustness.

The global market is evermore volatile and turbulent; it requires rapid responses to the emerging customers needs, also to unpredictable ones. Companies are forced towards a continuous research and innovation in terms of flexible technologies and processes in order to provide a high level of market adaptability. In this context, agile approaches, intended as a set of strategies to face the market variability, have to be investigated. They have to interest all processes related to the product development phase. This paper is focused on how to implement an efficient agile strategy in product design. The proposed approach is based on product modularity and on the integration of computer-aided design (CAD)-based tools to support feasibility analysis on virtual prototypes. It allows the concurrent management of possible changes in both product and process platforms by adopting virtual prototypes for performing simulations. The implemented platforms and the connected virtual prototype are structured according t...

The use of modularity in the design of a new product or the adoption of a product platform, as the base to define new solutions within a product family, offers the company a chance to meet diverse customer needs at low cost because of economies of scale in all phases of the product's life cycle. At present, the concept of modularity in product design is becoming widely used in many industries such as automobiles and consumer electronics. However, if modularity and mass customization have attracted the interest of industries and researchers, the greatest efforts have been focused on the theoretical aspect whereas the related design support technologies have been only partially implemented. In this context, our intent is to develop highly reusable models, which are able to reconfigure themselves on the basis of new functional requirements. The proposed approach is based on the definition of what we callself-configuring componentsandmultiple-level functions. To describe the approach, a practical example related to the design of modules for woodworking machines is reported.

Design activity consists, strictly speaking, in synthesizing something new (or arranging existing things in a new way) to satisfy a recognized need. This activity is accomplished through an iterative, knowledge-based, decision-making process. One of the goals pursued by IT applied to product development has been Design Automation that is the execution of all tasks of the design process of a product by a software application. In this context, engineering knowledge elicitation, representation and management are key issues to achieve the so-called “right the first time” design. This chapter summarizes authors research in Mechanical Design Automation (MDA) domain during the last two decades; it focuses the evolution from CAD centered applications to Object-Oriented (O-O) ones up until the more recent issues related to storing, sharing and reusing of engineering knowledge, the role in PLM approach and the support to decision-making. Finally, the fundamental aspects related to development of real-MDA applications are discussed, on the basis of personal experiences of the authors.

Companies applying mass customization paradigm regard the design process as a configuration task where the solution is achieved through the extraction of a new instance from a modular product structure. In this context product configuration management tools are evermore important. Although tools have been already proposed, they fail in real industrial contexts. Main causes are recognizable in high efforts in systems implementation and lack of flexibility in products updating. This research aims to develop an approach to overcome drawbacks and simplify the implementation and the use of product configuration systems also in redesign activities. The paper initially reviews existing systems in terms of design knowledge representation methods and product structure formalization techniques. Then, an approach based on Configuration Virtual Prototypes which store and manage different levels of knowledge, is presented. In particular, a framework is outlined in order to represent design data and its formalization in configuration tools. Three different domains are managed and connected via Configuration Virtual Prototypes: Product Specifications, Geometrical Data and Product Knowledge. Specifically, geometrical data aspects are analyzed in detail providing approaches for eliciting knowledge introduced by parametric template CAD models. The approach will be exemplified through a real application example where an original tool has been developed on the based of the described method. Benefits of the system will be shown and briefly discussed, in particular in terms of reachable flexibility in solutions.Copyright © 2009 by ASME

Virtual Reality (VR) systems provide new modes of human computer interaction that can support several industrial design applications improving time savings, reducing prototyping costs, and supporting the identification of design errors before production. Enhancing the interaction between humans and virtual prototypes by involving multiple sensorial modalities, VR can be adopted to perform ergonomic analysis. The main problems deal with the evaluation both of functional and cognitive sample users behavior as VR interfaces influence the perception of the ergonomic human factors. We state that ergonomic analysis performed in virtual environment can be successful only if supported with a structured protocol for the study both of functional and cognitive aspects and with the proper VR technologies combination that answers to the specific analysis tasks. An ergonomic analysis protocol is presented. It allows the assessment of the consumers’ response in term of behavioral and cognitive human factors, comprehending both operational and emotional agents. The protocol is also used to identify the best combination of visualization and haptic interfaces to perform the analysis. An experimental example, belonging to house appliances field is adopted to investigate the application of the protocol in the virtual set up.Copyright © 2008 by ASME

Concurrent Engineering methodology and process analysis and modeling showed the importance of tools that allow the designers to evaluate, from the beginning, different aspects of product definition. 3D CAD systems, simulation tools and virtual prototyping technologies can support the designer during her/his decision-making activity but, in order to provide an effective support, they must be tailored to the needs of the design process of each specific product.

This paper presents a multi-level approach to define a product model. It is based on the concept of what we call “Intelligent” Component. In order to be able to manage contextually the different types of knowledge involved during the design process, the multi-level model reflects the different steps of the process itself. To describe the approach an applicative example related to shaft design has been implemented. We first illustrate how to define an “Intelligent” Component for shaft design, and, then, how to extend a single-part approach to a library of mechanical “intelligent” components that allow developing complex models. It permits to show how a multi-level product model is able to capture and represent the design process from the preliminary to the detail stage, formalising all the information concerning the behaviour of the model within different application contexts.

Knowledge based engineering is a technology whose aim is to provide tools to develop vertical applications which can integrate different types of knowledge representation within a common model and carry out model evaluation, modification and updating. This paper presents a knowledge based engineering application to support the design of Indy Racing League (IRL) cars. The IRL Championship is regulated by a very strict set of technical specifications, which limit the designer as far as car structure and sizes of the parts are concerned. For this reason it is very important to evaluate the effects of modifying main design parameters on the car configuration. The first part of the paper describes how Dallara’s know-how on IRL car design has been reorganized with specific reference to the problem of weight distribution. This has led to the definition of a hierarchical IRL car model containing the fundamental parameters for weight computation. In the second part the use of examples highlights that different types of knowledge representation are necessary to compute weights distribution. The final part contains the description of the prototype implemented by using results from the previous phases. Comparing the results obtained with experimental data has validated the application.

The application of life cycle assessment (LCA) is usually aimed at products where most parameters relating to architecture, processes and materials are defined and known. However, application of conventional LCA for products or services that are incomplete in their specification is quite difficult or even impossible, if too many significant parameters are unknown. In our previous work targeting the development of eco-design tools, an approach integrating LCA methodology with the concept of product modularity has been introduced. In this paper, further improvements of this novel approach, being based on fuzzy logic and its application, are presented. In this context, fuzzy logic is being used to increase user friendliness of the interface while avoiding any circumstances of compromising the precision of quantitative results computed. A set of fuzzy attributes, membership functions and an inference algorithm are used to evaluate the modification of design parameters of modular products regarding their influence on environmental impact indicators.

The authors present a prototype of an expert system for the automatic recognition of form features. The paper points out how the recognition activity is a useful tool to realize the integration of design activities with manufacturing, handling, assembling etc. The concept on which the system is based is the possibility to utilize, in processes from the design to the manufacturing of a mechanical part, a common model for solid model representation and a set of tools which permits in different contexts, the extraction of information useful to carry out the activities within the considered context. The system is characterized by a rule-based architecture that allows great flexibility and is easily adapted to different contexts. The solid representation model is of the B-rep type while for rules' formalization a particular rewriting system, called caIL (Conditional Attributed Lindenmayer system with Interaction), has been adopted. In particular in this paper the grasping context is pointed out. >

Identifying theories and methods to link geometrica l tolerances specification and inspection processes is a widely spread researc h topic. The growing use of virtual product models which not only represent the geometry information, but also collect attributes, notes, parameters, rules and procedures , can facilitate the digital simulation of many real processes. In the present work we are interested in using such technologies for the purpose of simulating the inspection proces s of manufactured products. In particular, we propose an approach for virtual insp ection of geometrical tolerances based on a feature-based 3D CAD model coupled with a 3D points cloud data model. The 3D CAD model stores the tolerances specificati ons defined by the designer as well as the specification of the inspection methods. The points cloud model is a complete representation of the manufactured product and it i s defined by the digital acquisition of the real product. The acquisition phase is performe d with non-contact techniques to ensure high performances in terms of speed. The inf ormation stored in the CAD model is used to select and drive the different inspectio n procedures to be performed on the acquired data.

Since the assessment of the novelty, feasibility and value of new product ideas is highly subjective and uncertain, it is hard for companies to come up with a final product which successfully embodies customer needs, as well as company requirements. The major goal of this study is to propose a design and managerial step-based framework, moving from idea generation until the early steps of concept embodiment. Russian Theory of Inventive Problem Solving, together with multicriteria-based selection methods are employed. A case study from the household appliances industry is presented, discussing how to guide technical solutions implementation in new product ideas.