https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Thu, 12 Mar 2026 11:24:25 GMT 2026-03-12T11:24:25Z http://hdl.handle.net/10985/8324 Towards recovery of complex shapes in meshes using digital images for reverse engineering applications PANCHETTI, Minica; PERNOT, Jean-Philippe; VERON, Philippe When an object owns complex shapes, or when its outer surfaces are simply inaccessible, some of its parts may not be captured during its reverse engineering. These deficiencies in the point cloud result in a set of holes in the reconstructed mesh. This paper deals with the use of information extracted from digital images to recover missing areas of a physical object. The proposed algorithm fills in these holes by solving an optimization problem that combines two kinds of information: (1) the geometric information available on the surrounding of the holes, (2) the information contained in an image of the real object. The constraints come from the image irradiance equation, a first-order non-linear partial differential equation that links the position of the mesh vertices to the light intensity of the image pixels. The blending conditions are satisfied by using an objective function based on a mechanical model of bar network that simulates the curvature evolution over the mesh. The inherent shortcomings both to the current holefilling algorithms and the resolution of the image irradiance equations are overcome Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/8324 2010-01-01T00:00:00Z PANCHETTI, Minica PERNOT, Jean-Philippe VERON, Philippe When an object owns complex shapes, or when its outer surfaces are simply inaccessible, some of its parts may not be captured during its reverse engineering. These deficiencies in the point cloud result in a set of holes in the reconstructed mesh. This paper deals with the use of information extracted from digital images to recover missing areas of a physical object. The proposed algorithm fills in these holes by solving an optimization problem that combines two kinds of information: (1) the geometric information available on the surrounding of the holes, (2) the information contained in an image of the real object. The constraints come from the image irradiance equation, a first-order non-linear partial differential equation that links the position of the mesh vertices to the light intensity of the image pixels. The blending conditions are satisfied by using an objective function based on a mechanical model of bar network that simulates the curvature evolution over the mesh. The inherent shortcomings both to the current holefilling algorithms and the resolution of the image irradiance equations are overcome http://hdl.handle.net/10985/8329 A design-for-casting integrated approach based on rapid simulation and modulus criterion MARTIN, Lionel; MORARU, George; VERON, Philippe This paper presents a new approach to the design of cast components and their associated tools. The current methodology is analysed through a case study and its main disadvantages underlined. Then, in order to overcome these identified drawbacks, a new approach is proposed. Knowing that this approach is mainly based on a rapid simulation of the process, basics of a simplified physical model of solidification are presented as well as an associated modulus criterion. Finally, technical matters for a software prototype regarding the implementation of this Rapid Simulation Approach (RSA) in a CAD environment are detailed. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/10985/8329 2009-01-01T00:00:00Z MARTIN, Lionel MORARU, George VERON, Philippe This paper presents a new approach to the design of cast components and their associated tools. The current methodology is analysed through a case study and its main disadvantages underlined. Then, in order to overcome these identified drawbacks, a new approach is proposed. Knowing that this approach is mainly based on a rapid simulation of the process, basics of a simplified physical model of solidification are presented as well as an associated modulus criterion. Finally, technical matters for a software prototype regarding the implementation of this Rapid Simulation Approach (RSA) in a CAD environment are detailed. http://hdl.handle.net/10985/6565 Collaborative Reverse Engineering Design Experiment Using PLM Solutions MARANZANA, Nicolas; SEGONDS, Frederic; VERON, Philippe; AOUSSAT, Améziane The current climate of economic competition forces businesses to adapt to the expectations of their customers. To achieve this, in spite of the increasing complexity of mechanical systems, it becomes necessary, amongst other things, to reduce design time. Faced with new challenges, practices in design training must evolve to allow students to be mindful of these evolutions as well as to be able to manage projects in these new work environments. After presenting a state of the art of collaborative tools used in product design, our paper presents an experiment focusing on the reverse engineering of a complex mechanical product. This experiment was carried out between two centers of the Arts et Métiers ParisTech School of Engineering, located in Paris and Angers.Weanalyze the results obtained in this experiment and propose a collaborative environment that is well suited to our needs for design education, based on ‘‘Product Lifecycle Managament’’ (PLM) concepts. Finally, we present some modifications in collaborative design courses for our students, and we implement network modifications in order to significantly improve the ease of use of the design environment. Sat, 01 Jan 2011 00:00:00 GMT http://hdl.handle.net/10985/6565 2011-01-01T00:00:00Z MARANZANA, Nicolas SEGONDS, Frederic VERON, Philippe AOUSSAT, Améziane The current climate of economic competition forces businesses to adapt to the expectations of their customers. To achieve this, in spite of the increasing complexity of mechanical systems, it becomes necessary, amongst other things, to reduce design time. Faced with new challenges, practices in design training must evolve to allow students to be mindful of these evolutions as well as to be able to manage projects in these new work environments. After presenting a state of the art of collaborative tools used in product design, our paper presents an experiment focusing on the reverse engineering of a complex mechanical product. This experiment was carried out between two centers of the Arts et Métiers ParisTech School of Engineering, located in Paris and Angers.Weanalyze the results obtained in this experiment and propose a collaborative environment that is well suited to our needs for design education, based on ‘‘Product Lifecycle Managament’’ (PLM) concepts. Finally, we present some modifications in collaborative design courses for our students, and we implement network modifications in order to significantly improve the ease of use of the design environment. http://hdl.handle.net/10985/8328 Repairing triangle meshes built from scanned point cloud MORARU, George; PERNOT, Jean-Philippe; VERON, Philippe The Reverse Engineering process consists of a succession of operations that aim at creating a digital representation of a physical model. The reconstructed geometric model is often a triangle mesh built from a point cloud acquired with a scanner. Depending on both the object complexity and the scanning process, some areas of the object outer surface may never be accessible, thus inducing some deficiencies in the point cloud and, as a consequence, some holes in the resulting mesh. This is simply not acceptable in an integrated design process where the geometric models are often shared between the various applications (e.g. design, simulation, manufacturing). In this paper, we propose a complete toolbox to fill in these undesirable holes. The hole contour is first cleaned to remove badly-shaped triangles that are due to the scanner noise. A topological grid is then inserted and deformed to satisfy blending conditions with the surrounding mesh. In our approach, the shape of the inserted mesh results from the minimization of a quadratic function based on a linear mechanical model that is used to approximate the curvature variation between the inner and surrounding meshes. Additional geometric constraints can also be specified to further shape the inserted mesh. The proposed approach is illustrated with some examples coming from our prototype software. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10985/8328 2007-01-01T00:00:00Z MORARU, George PERNOT, Jean-Philippe VERON, Philippe The Reverse Engineering process consists of a succession of operations that aim at creating a digital representation of a physical model. The reconstructed geometric model is often a triangle mesh built from a point cloud acquired with a scanner. Depending on both the object complexity and the scanning process, some areas of the object outer surface may never be accessible, thus inducing some deficiencies in the point cloud and, as a consequence, some holes in the resulting mesh. This is simply not acceptable in an integrated design process where the geometric models are often shared between the various applications (e.g. design, simulation, manufacturing). In this paper, we propose a complete toolbox to fill in these undesirable holes. The hole contour is first cleaned to remove badly-shaped triangles that are due to the scanner noise. A topological grid is then inserted and deformed to satisfy blending conditions with the surrounding mesh. In our approach, the shape of the inserted mesh results from the minimization of a quadratic function based on a linear mechanical model that is used to approximate the curvature variation between the inner and surrounding meshes. Additional geometric constraints can also be specified to further shape the inserted mesh. The proposed approach is illustrated with some examples coming from our prototype software. http://hdl.handle.net/10985/8959 Experimental analysis and simulation of the dynamic response of a propeller pitch change actuator LECLERCQ, Maxime; MALBURET, François; VERON, Philippe This paper focuses specifically on the control of the propeller pitch change mechanisms and their associated dynamics. The subject of this article is restricted to the mechanisms using a hydraulic single acting actuator. They function asymmetrically and are subject to important varying external loads under the full flight envelope. This phenomenon has an impact on their dynamic response. The question of the dynamics of these systems is rarely dealt with because, usually for aircraft applications, there is no real requirement for propeller pitch dynamic control. But, in the case of some applications, such as the Eurocopter X3, this dynamic control aspect and the safety aspect of the propeller pitch change mechanism are particularly important, because this mechanism is fully involved in aircraft safety, control and handling qualities. Firstly, this paper gives an explanation of the phenomena applied to the propeller pitch change mechanism and their contributions to its dynamic response. Then, a model of the dynamic response is proposed. Finally, an experimental identification of the pitch change mechanism dynamics concludes this article. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/10985/8959 2012-01-01T00:00:00Z LECLERCQ, Maxime MALBURET, François VERON, Philippe This paper focuses specifically on the control of the propeller pitch change mechanisms and their associated dynamics. The subject of this article is restricted to the mechanisms using a hydraulic single acting actuator. They function asymmetrically and are subject to important varying external loads under the full flight envelope. This phenomenon has an impact on their dynamic response. The question of the dynamics of these systems is rarely dealt with because, usually for aircraft applications, there is no real requirement for propeller pitch dynamic control. But, in the case of some applications, such as the Eurocopter X3, this dynamic control aspect and the safety aspect of the propeller pitch change mechanism are particularly important, because this mechanism is fully involved in aircraft safety, control and handling qualities. Firstly, this paper gives an explanation of the phenomena applied to the propeller pitch change mechanism and their contributions to its dynamic response. Then, a model of the dynamic response is proposed. Finally, an experimental identification of the pitch change mechanism dynamics concludes this article. http://hdl.handle.net/10985/8325 Direct modification of semanticaly-enriched finite element meshes GIANNINI, Franca; FALCIDIENO, Bianca; MIKCHEVITCH, Alexei; MARC, Raphael; PERNOT, Jean-Philippe; LOU, Ruding; VERON, Philippe Behaviour analysis loop is largely performed on virtual product model before its physical manufacturing. The last avoids high expenses in terms of money and time spent on intermediate manufacturing. It is gainful from the reality to the virtuality but the process could be further optimized especially during the product behaviour optimization phase. This process involves repetition of four main processing steps: CAD design and modification, mesh creation, Finite Element (FE) model generation with the association of physical and geometric data, FE Analysis. The product behaviour analysis loop is performed on the rst design solution as well as on the numerous successive product optimization loops. Each design solution evaluation necessitates the same time as required for the first product design that is particularly crucial in the context of maintenance. In this paper we propose a new framework for CAD-less product optimisation through FE analysis which reduces the model preparation activities traditionally required for FE model creation. More concretely, the idea is to directly operate on the rstly created FE mesh, enriched with physical/geometric semantics, to perform the product modi cations required to achieve its optimised version. In order to accomplish the proposed CAD-less FE analysis framework, modification operators acting on both the mesh geometry and the associated semantics need to be devised. In this paper we discuss the underlying concepts and present possible components for the development of such operators. A high-level operator speci cation is proposed according to a modular structure that allows an easy realisation of di erent mesh modification operators. Here, two instances of this high-level operator are described: the planar cracking and the drilling. The realised prototypes validated on industrial FE models show clearly the feasibility of this approach. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/8325 2010-01-01T00:00:00Z GIANNINI, Franca FALCIDIENO, Bianca MIKCHEVITCH, Alexei MARC, Raphael PERNOT, Jean-Philippe LOU, Ruding VERON, Philippe Behaviour analysis loop is largely performed on virtual product model before its physical manufacturing. The last avoids high expenses in terms of money and time spent on intermediate manufacturing. It is gainful from the reality to the virtuality but the process could be further optimized especially during the product behaviour optimization phase. This process involves repetition of four main processing steps: CAD design and modification, mesh creation, Finite Element (FE) model generation with the association of physical and geometric data, FE Analysis. The product behaviour analysis loop is performed on the rst design solution as well as on the numerous successive product optimization loops. Each design solution evaluation necessitates the same time as required for the first product design that is particularly crucial in the context of maintenance. In this paper we propose a new framework for CAD-less product optimisation through FE analysis which reduces the model preparation activities traditionally required for FE model creation. More concretely, the idea is to directly operate on the rstly created FE mesh, enriched with physical/geometric semantics, to perform the product modi cations required to achieve its optimised version. In order to accomplish the proposed CAD-less FE analysis framework, modification operators acting on both the mesh geometry and the associated semantics need to be devised. In this paper we discuss the underlying concepts and present possible components for the development of such operators. A high-level operator speci cation is proposed according to a modular structure that allows an easy realisation of di erent mesh modification operators. Here, two instances of this high-level operator are described: the planar cracking and the drilling. The realised prototypes validated on industrial FE models show clearly the feasibility of this approach. http://hdl.handle.net/10985/8326 A generic formalism for the semantic modeling and representation of architectural elements DE LUCA, Livio; FLORENZANO, Michel; VERON, Philippe This article presents a methodological approach to the semantic description of architectural elements based both on theoretical reflections and research experiences. To develop this approach, a first process of extraction and formalization of architectural knowledge on the basis of the analysis of architectural treaties is proposed. Then, the identified features are used to produce a template shape library dedicated to buildings surveying. Finally, the problem of the overall model structuring and organization using semantic information is addressed for user handling purposes. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10985/8326 2007-01-01T00:00:00Z DE LUCA, Livio FLORENZANO, Michel VERON, Philippe This article presents a methodological approach to the semantic description of architectural elements based both on theoretical reflections and research experiences. To develop this approach, a first process of extraction and formalization of architectural knowledge on the basis of the analysis of architectural treaties is proposed. Then, the identified features are used to produce a template shape library dedicated to buildings surveying. Finally, the problem of the overall model structuring and organization using semantic information is addressed for user handling purposes. http://hdl.handle.net/10985/9838 Review of the “ as-buit BIM ” approaches HICHRI, Nouha; STEFANI, Chiara; DE LUCA, Livio; VERON, Philippe Today, we need 3D models of heritage buildings in order to handle more efficiently projects of restoration, documentation and maintenance. In this context, developing a performing approach, based on a first phase of building survey, is a necessary step in order to build a semantically enriched digital model. For this purpose, the Building Information Modeling is an efficient tool for storing and exchanging knowledge about buildings. In order to create such a model, there are three fundamental steps: acquisition, segmentation and modeling. For these reasons, it is essential to understand and analyze this entire chain that leads to a well- structured and enriched 3D digital model. This paper proposes a survey and an analysis of the existing approaches on these topics and tries to define a new approach of semantic structuring taking into account the complexity of this chain. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/9838 2013-01-01T00:00:00Z HICHRI, Nouha STEFANI, Chiara DE LUCA, Livio VERON, Philippe Today, we need 3D models of heritage buildings in order to handle more efficiently projects of restoration, documentation and maintenance. In this context, developing a performing approach, based on a first phase of building survey, is a necessary step in order to build a semantically enriched digital model. For this purpose, the Building Information Modeling is an efficient tool for storing and exchanging knowledge about buildings. In order to create such a model, there are three fundamental steps: acquisition, segmentation and modeling. For these reasons, it is essential to understand and analyze this entire chain that leads to a well- structured and enriched 3D digital model. This paper proposes a survey and an analysis of the existing approaches on these topics and tries to define a new approach of semantic structuring taking into account the complexity of this chain. http://hdl.handle.net/10985/6716 The use of early design tools in engineering processes : a comparative case study IRAQI-HOUSSAINI, Mehdi; ROUCOULES, Lionel; SEGONDS, Frederic; VERON, Philippe; AOUSSAT, Améziane Nowadays, product design is increasingly complex: not only must it answer customer needs through complex functions; it must also ensure traceability throughout the design process, keeping in mind that standards and stringent regulations must be complied with. Faced with new challenges, engineering practices have evolved to allow stakeholders to be able to manage projects in new work environments, especially during the early stages of design. After presenting a state of the art of early design tools used in product design and their integration in PLM context, we compare class diagrams for two of them : TDC software (Knowllence©) and RFLP module of CATIA V6 (Dassault Systems©). Then, our paper presents an experiment focusing on these tools, which aims to assess their usability, to evaluate and compare them. Users can raise issues, take note of which functionalities are appreciated, and provide qualitative feedback. We analyze the results obtained in this experiment and propose a comparison based on four topics: learnability, satisfaction of users, efficiency and error correction. Finally, we present some links between class diagrams and usability of the tools. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/6716 2010-01-01T00:00:00Z IRAQI-HOUSSAINI, Mehdi ROUCOULES, Lionel SEGONDS, Frederic VERON, Philippe AOUSSAT, Améziane Nowadays, product design is increasingly complex: not only must it answer customer needs through complex functions; it must also ensure traceability throughout the design process, keeping in mind that standards and stringent regulations must be complied with. Faced with new challenges, engineering practices have evolved to allow stakeholders to be able to manage projects in new work environments, especially during the early stages of design. After presenting a state of the art of early design tools used in product design and their integration in PLM context, we compare class diagrams for two of them : TDC software (Knowllence©) and RFLP module of CATIA V6 (Dassault Systems©). Then, our paper presents an experiment focusing on these tools, which aims to assess their usability, to evaluate and compare them. Users can raise issues, take note of which functionalities are appreciated, and provide qualitative feedback. We analyze the results obtained in this experiment and propose a comparison based on four topics: learnability, satisfaction of users, efficiency and error correction. Finally, we present some links between class diagrams and usability of the tools. http://hdl.handle.net/10985/9336 Filleting sharp edges of multi-partitioned volume finite element meshes GIANNINI, Franca; FALCIDIENO, Bianca; PERNOT, Jean-Philippe; LOU, Ruding; VERON, Philippe Purpose – The purpose of this paper is to set up a new framework to enable direct modifications of volume meshes enriched with semantic information associated to multiple partitions. An instance of filleting operator is prototyped under this framework and presented in the paper. Design/methodology/approach – In this paper, a generic mesh modification operator has been designed and a new instance of this operator for filleting finite element (FE) sharp edges of tetrahedral multi-partitioned meshes is also pro-posed. The filleting operator works in two main steps. The outer skin of the tetrahedral mesh is first deformed to round user-specified sharp edges while satisfying constraints relative to the shape of the so-called Virtual Group Boundaries. Then, in the filleting area, the positions of the inner nodes are relaxed to improve the aspect ratio of the mesh elements. Findings – The classical mainstream methodology for product behaviour optimization involves the repetition of four steps: CAD modelling, meshing of CAD models, enrichment of models with FE simulation semantics and FEA. This paper highlights how this methodology could be simplified by two steps: simulation model modification and FEA. The authors set up a new framework to enable direct modifications of volume meshes enriched with semantic information associated to multiple and the corresponding fillet operator is devised. Research limitations/implications – The proposed framework shows only a paradigm of direct modifications of semantic enriched meshes. It could be further more improved by adding or changing the modules inside. The fillet operator does not take into account the exact radius imposed by user. With this proposed fillet operator the mesh element density may not be enough high to obtain wished smoothness. Originality/value – This paper fulfils an identified industry need to speed up the product behaviour analysis process by directly modifying the simulation semantic enriched meshes. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9336 2015-01-01T00:00:00Z GIANNINI, Franca FALCIDIENO, Bianca PERNOT, Jean-Philippe LOU, Ruding VERON, Philippe Purpose – The purpose of this paper is to set up a new framework to enable direct modifications of volume meshes enriched with semantic information associated to multiple partitions. An instance of filleting operator is prototyped under this framework and presented in the paper. Design/methodology/approach – In this paper, a generic mesh modification operator has been designed and a new instance of this operator for filleting finite element (FE) sharp edges of tetrahedral multi-partitioned meshes is also pro-posed. The filleting operator works in two main steps. The outer skin of the tetrahedral mesh is first deformed to round user-specified sharp edges while satisfying constraints relative to the shape of the so-called Virtual Group Boundaries. Then, in the filleting area, the positions of the inner nodes are relaxed to improve the aspect ratio of the mesh elements. Findings – The classical mainstream methodology for product behaviour optimization involves the repetition of four steps: CAD modelling, meshing of CAD models, enrichment of models with FE simulation semantics and FEA. This paper highlights how this methodology could be simplified by two steps: simulation model modification and FEA. The authors set up a new framework to enable direct modifications of volume meshes enriched with semantic information associated to multiple and the corresponding fillet operator is devised. Research limitations/implications – The proposed framework shows only a paradigm of direct modifications of semantic enriched meshes. It could be further more improved by adding or changing the modules inside. The fillet operator does not take into account the exact radius imposed by user. With this proposed fillet operator the mesh element density may not be enough high to obtain wished smoothness. Originality/value – This paper fulfils an identified industry need to speed up the product behaviour analysis process by directly modifying the simulation semantic enriched meshes.