https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Sun, 17 May 2026 09:07:12 GMT 2026-05-17T09:07:12Z 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/10985/9336 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. http://hdl.handle.net/10985/9777 Towards semantic-based 3D mesh modeling GIANNINI, Franca; MIKCHEVITECH, Alexei; FALCIDIENO, Bianca; MARC, Raphael; PERNOT, Jean-Philippe; LOU, Ruding; VERON, Philippe Nowadays, most of the numerical simulations in product maintenance are carried out by several loops of the following steps: 1) CAD model creation/optimization, 2) Finite Element (FE) mesh generation, 3) insertion of semantic data for physical simulation (e.g. material behavior laws, boundary conditions) and 4) FE simulation and analysis of the results. The four steps are repeated for the evaluation of each conceived maintenance solution. The semantic data are attached to the mesh through the use of groups of mesh entities sharing the same semantic characteristics. Thus, any modification of the CAD model always implies an update of the mesh as well as an update of the attached semantic data. This is time-consuming and thus not suitable for industrial maintenance. Moreover, the CAD models do not always exist and should therefore be reconstructed starting from scratch or from the scanned physical object. In this paper, we propose a framework towards the definition of semantics based CAD-less operators wherein semantic enriched meshes are manipulated directly. This work also finds interest in the preliminary design phases where alternative solutions have to be quickly evaluated Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/9777 2010-01-01T00:00:00Z GIANNINI, Franca MIKCHEVITECH, Alexei FALCIDIENO, Bianca MARC, Raphael PERNOT, Jean-Philippe LOU, Ruding VERON, Philippe Nowadays, most of the numerical simulations in product maintenance are carried out by several loops of the following steps: 1) CAD model creation/optimization, 2) Finite Element (FE) mesh generation, 3) insertion of semantic data for physical simulation (e.g. material behavior laws, boundary conditions) and 4) FE simulation and analysis of the results. The four steps are repeated for the evaluation of each conceived maintenance solution. The semantic data are attached to the mesh through the use of groups of mesh entities sharing the same semantic characteristics. Thus, any modification of the CAD model always implies an update of the mesh as well as an update of the attached semantic data. This is time-consuming and thus not suitable for industrial maintenance. Moreover, the CAD models do not always exist and should therefore be reconstructed starting from scratch or from the scanned physical object. In this paper, we propose a framework towards the definition of semantics based CAD-less operators wherein semantic enriched meshes are manipulated directly. This work also finds interest in the preliminary design phases where alternative solutions have to be quickly evaluated http://hdl.handle.net/10985/8374 Merging enriched Finite Element triangle meshes for fast prototyping of alternate solutions in the context of industrial maintenance MIKCHEVITCH, Alexei; PERNOT, Jean-Philippe; LOU, Ruding; VERON, Philippe A new approach to the merging of Finite Element (FE) triangle meshes is proposed. Not only it takes into account the geometric aspects, but it also considers the way the semantic information possibly associated to the groups of entities (nodes, faces) can be maintained. Such high level modification capabilities are of major importance in all the engineering activities requiring fast modifications of meshes without going back to the CAD model. This is especially true in the context of industrial maintenance where the engineers often have to solve critical problems in very short time. Indeed, in this case, the product is already designed, the CAD models are not necessarily available and the FE models might be tuned. Thus, the product behaviour has to be studied and improved during its exploitation while prototyping directly several alternate solutions. Such a framework also finds interest in the preliminary design phases where alternative solutions have to be simulated. The algorithm first removes the intersecting faces in an n-ring neighbourhood so that the filling of the created holes produces triangles whose sizes smoothly evolve according to the possibly heterogeneous sizes of the surrounding triagles. The holefilling algorithm is driven by an aspect ratio factor which ensures that the produced triangulation fits well the FE requirements. It is also constrained by the boundaries of the groups of entities gathering together the simulation semantic. The filled areas are then deformed to blend smoothly with the surroundings meshes. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/8374 2010-01-01T00:00:00Z MIKCHEVITCH, Alexei PERNOT, Jean-Philippe LOU, Ruding VERON, Philippe A new approach to the merging of Finite Element (FE) triangle meshes is proposed. Not only it takes into account the geometric aspects, but it also considers the way the semantic information possibly associated to the groups of entities (nodes, faces) can be maintained. Such high level modification capabilities are of major importance in all the engineering activities requiring fast modifications of meshes without going back to the CAD model. This is especially true in the context of industrial maintenance where the engineers often have to solve critical problems in very short time. Indeed, in this case, the product is already designed, the CAD models are not necessarily available and the FE models might be tuned. Thus, the product behaviour has to be studied and improved during its exploitation while prototyping directly several alternate solutions. Such a framework also finds interest in the preliminary design phases where alternative solutions have to be simulated. The algorithm first removes the intersecting faces in an n-ring neighbourhood so that the filling of the created holes produces triangles whose sizes smoothly evolve according to the possibly heterogeneous sizes of the surrounding triagles. The holefilling algorithm is driven by an aspect ratio factor which ensures that the produced triangulation fits well the FE requirements. It is also constrained by the boundaries of the groups of entities gathering together the simulation semantic. The filled areas are then deformed to blend smoothly with the surroundings meshes. http://hdl.handle.net/10985/8522 Generation of subdivision surface from network of curves LI, Zhihua; LOU, Ruding Subdivision surfaces are usually used to construct freeform surfaces from network of curves for its ability and flexibility to deal with complex wireframes. In freeform surface designing, the designers usually draw at first some curves for describing the models conceived in their mind which form a curve network representing an object of arbitrary topology. Then 3D surfaces are computed to interpolate these curves in order to create a B-Rep model. If the subdivision surface is used in the workflow, its control polyhedrons generation from curves polygons could be a time-consuming stage. In this article, we develop an approach to generate automatically a control polyhedral mesh from an arbitrary topological curve network. One of common problems in interpolating surface patch using subdivision surfaces is how to determine the connectivity of control points. Arbitrary topological curve network has no restriction in topology structure, so another problem is that it has more ambiguousness in defining surface patches. There are three steps in our approach. Firstly, we compute a 1D mesh (a unique polygonal model) from curves. Secondly, we identify on the polygon different cycles that would be the boundaries of potential surface patches. Finally, in each identified cycle we apply an algorithm of quadrangulation to construct the control mesh of subdivision. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/8522 2014-01-01T00:00:00Z LI, Zhihua LOU, Ruding Subdivision surfaces are usually used to construct freeform surfaces from network of curves for its ability and flexibility to deal with complex wireframes. In freeform surface designing, the designers usually draw at first some curves for describing the models conceived in their mind which form a curve network representing an object of arbitrary topology. Then 3D surfaces are computed to interpolate these curves in order to create a B-Rep model. If the subdivision surface is used in the workflow, its control polyhedrons generation from curves polygons could be a time-consuming stage. In this article, we develop an approach to generate automatically a control polyhedral mesh from an arbitrary topological curve network. One of common problems in interpolating surface patch using subdivision surfaces is how to determine the connectivity of control points. Arbitrary topological curve network has no restriction in topology structure, so another problem is that it has more ambiguousness in defining surface patches. There are three steps in our approach. Firstly, we compute a 1D mesh (a unique polygonal model) from curves. Secondly, we identify on the polygon different cycles that would be the boundaries of potential surface patches. Finally, in each identified cycle we apply an algorithm of quadrangulation to construct the control mesh of subdivision. http://hdl.handle.net/10985/13055 Multi-view VR system for co-located multidisciplinary collaboration and its application in ergonomic design LI, Bo; LOU, Ruding; POSSELT, Javier; SEGONDS, Frederic; MERIENNE, Frédéric; KEMENY, Andras In co-located collaborative environment for product design, new groupware of multi-view system allows multiple experts to have individual visual information. A co-located multi-view VR system and a multidisciplinary task have been created and studied. Results show that using multi-view VR system achieves a better effectiveness and user performance. Then, an application for collaborative ergonomic design is explored and an industrial multidisciplinary scenario is realized with proposed system. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/13055 2017-01-01T00:00:00Z LI, Bo LOU, Ruding POSSELT, Javier SEGONDS, Frederic MERIENNE, Frédéric KEMENY, Andras In co-located collaborative environment for product design, new groupware of multi-view system allows multiple experts to have individual visual information. A co-located multi-view VR system and a multidisciplinary task have been created and studied. Results show that using multi-view VR system achieves a better effectiveness and user performance. Then, an application for collaborative ergonomic design is explored and an industrial multidisciplinary scenario is realized with proposed system. http://hdl.handle.net/10985/13735 Design and prototyping of an interactive virtual environment to foster citizen participation and creativity in urban design FALIU, Barnabé; SIARHEYEVA, Alena; MERIENNE, Frédéric; LOU, Ruding Public Participation encounters great challenges in the domain of urban design concerning decision making and citizens’ appropriation of a future place. Many tools and methods have been proposed to ease the participation process. In this paper we are targeting artefacts used in face-to-face workshops, in which citizens are asked to make design proposals for a public space. We claim that current state of the art can be improved (i) by better articulating digital artefacts with participatory processes and (ii) by providing interfaces that enhance citizen’s spatial awareness and comprehension as well as collective creativity in urban design projects. We present the design and prototyping of an interactive virtual environment that follow the design-science research guidelines. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/13735 2018-01-01T00:00:00Z FALIU, Barnabé SIARHEYEVA, Alena MERIENNE, Frédéric LOU, Ruding Public Participation encounters great challenges in the domain of urban design concerning decision making and citizens’ appropriation of a future place. Many tools and methods have been proposed to ease the participation process. In this paper we are targeting artefacts used in face-to-face workshops, in which citizens are asked to make design proposals for a public space. We claim that current state of the art can be improved (i) by better articulating digital artefacts with participatory processes and (ii) by providing interfaces that enhance citizen’s spatial awareness and comprehension as well as collective creativity in urban design projects. We present the design and prototyping of an interactive virtual environment that follow the design-science research guidelines. http://hdl.handle.net/10985/14175 Design in context of use: An experiment with a multi-view and multi-representation system for collaborative design LI, Bo; MATEEV, Céline; MERIENNE, Frédéric; LOU, Ruding; SEGONDS, Frederic The current trend of product design leads to a change in the collaborative working style. To find the most efficient way to exchange information on the digital mock-up of a product, a synchronous co-located collaborative design environment with recent technologies is in needed. A new groupware of multi-view system allows multiple users to have individual visual information of a domain-specific representation of digital mock-up. In this paper, we propose a case study for the development and testing of a co-located multi-view system in collaborative virtual reality, aiming at enhancing the multidisciplinary early collaborative design. An ergonomic method of Personas is introduced to the evaluation of the tool, considering various user performance. With a multidisciplinary mug design scenario, experiments are presented, validating the benefits of the proposed system. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/14175 2018-01-01T00:00:00Z LI, Bo MATEEV, Céline MERIENNE, Frédéric LOU, Ruding SEGONDS, Frederic The current trend of product design leads to a change in the collaborative working style. To find the most efficient way to exchange information on the digital mock-up of a product, a synchronous co-located collaborative design environment with recent technologies is in needed. A new groupware of multi-view system allows multiple users to have individual visual information of a domain-specific representation of digital mock-up. In this paper, we propose a case study for the development and testing of a co-located multi-view system in collaborative virtual reality, aiming at enhancing the multidisciplinary early collaborative design. An ergonomic method of Personas is introduced to the evaluation of the tool, considering various user performance. With a multidisciplinary mug design scenario, experiments are presented, validating the benefits of the proposed system. http://hdl.handle.net/10985/17658 Geometry deformation for reducing cybersickness in VR LOU, Ruding Virtual reality (VR) technologies became more and more widespread for a couple of years as they got more and more mature. The accessibility to VR highly increased thanks to recent low-cost commercial VR head mounted display systems and easy-to-use development toolkits. One important and well-studied human perception issue is related to motion sickness or cybersickness. In this paper we are dealing with case when users feel a visually induced induced self-motion that are not felt through their vestibular systems. This incoherent movement perception provokes cybersickness to the users. To tackle this issue, we present in this paper a novel method to reduce cybersickness through reducing visually induced self-motion by processing geometrically the virtual scene while navigating. The first prototype of geometry deformation applied on virtual building appearing in the peripheral vision of user has been implemented and experimented. The feedback from the experiment participants shows that the visually induced self-motion is reduced and the navigation quality and presence level are guaranteed. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/17658 2019-01-01T00:00:00Z LOU, Ruding Virtual reality (VR) technologies became more and more widespread for a couple of years as they got more and more mature. The accessibility to VR highly increased thanks to recent low-cost commercial VR head mounted display systems and easy-to-use development toolkits. One important and well-studied human perception issue is related to motion sickness or cybersickness. In this paper we are dealing with case when users feel a visually induced induced self-motion that are not felt through their vestibular systems. This incoherent movement perception provokes cybersickness to the users. To tackle this issue, we present in this paper a novel method to reduce cybersickness through reducing visually induced self-motion by processing geometrically the virtual scene while navigating. The first prototype of geometry deformation applied on virtual building appearing in the peripheral vision of user has been implemented and experimented. The feedback from the experiment participants shows that the visually induced self-motion is reduced and the navigation quality and presence level are guaranteed. http://hdl.handle.net/10985/17739 A Virtual Reality and BIM Approach for Clash Resolution RAIMBAUD, Pierre; BONILLA PALACIOS, Mateo; ROMERO CORTES, Juan Pablo; FIGUEROA, Pablo; HERNANDEZ, José Tiberio; MERIENNE, Frédéric; DANGLADE, Florence; LOU, Ruding In the Architecture, Construction and Engineering (AEC) industry, a crucial task is Building Information Modelling (BIM) models coordination. Clashes can be detected automatically by current BIM tools. Clash origins (parn et al., 2018), or avoidance (Singh et al., 2015) have been studied. But, clash resolution still needs the civil engineers’ expertise. Currently, in a computer with a 3D BIM tool, they use annotations. As previous research showed that Virtual Reality (VR) can help to perform better AEC tasks, in terms of time and accuracy (Chalhoup and Ayer, 2018), we propose an immersive VR tool to solve clashes. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/17739 2019-01-01T00:00:00Z RAIMBAUD, Pierre BONILLA PALACIOS, Mateo ROMERO CORTES, Juan Pablo FIGUEROA, Pablo HERNANDEZ, José Tiberio MERIENNE, Frédéric DANGLADE, Florence LOU, Ruding In the Architecture, Construction and Engineering (AEC) industry, a crucial task is Building Information Modelling (BIM) models coordination. Clashes can be detected automatically by current BIM tools. Clash origins (parn et al., 2018), or avoidance (Singh et al., 2015) have been studied. But, clash resolution still needs the civil engineers’ expertise. Currently, in a computer with a 3D BIM tool, they use annotations. As previous research showed that Virtual Reality (VR) can help to perform better AEC tasks, in terms of time and accuracy (Chalhoup and Ayer, 2018), we propose an immersive VR tool to solve clashes.