Using Volume Morphing to Alter Panel Designs to Compensate Shape Distortion in Assembly

2010 ◽  
Vol 10 (2) ◽  
Author(s):  
Ramon F. Sarraga ◽  
Paul A. LeBlanc ◽  
Thomas J. Oetjens
Keyword(s):  
Computer Graphics ◽  
Computer Aided Design ◽  
Computer Software ◽  
Standard Technique ◽  
Free Form ◽  
Annual Conference ◽  
Shape Distortion ◽  
Element Analysis ◽  
Displacement Vectors ◽  
Cad Models

As automotive panels are assembled in a vehicle, they are subjected to shape distorting forces, e.g., the pressure of door seals. A standard technique for preventing shape distortions is to alter the panels’ computer aided design (CAD) in such a way that the panels assume the desired design shape under the action of the distorting forces. Volume morphing, a technique pioneered by Bézier (1978, “General Distortion of an Ensemble of Biparametric Patches,” Comput.-Aided Des., 10(2), pp. 116–120) and by Sederberg and Parry (1986, “Free-Form Deformation of Solid Geometric Models,” International Conference on Computer Graphics and Interactive Techniques, Proceedings of the 13th Annual Conference on Computer Graphics, pp. 151–160), has been extended and implemented in a computer software package called FESHAPE, created at the General Motors Research and Development Center. FESHAPE automatically modifies CAD models according to a finite set of displacement vectors obtained, e.g., from finite-element analysis or scanning tryout parts. This article discusses how FESHAPE has been successfully applied to compensate door panel distortion caused by door seals.

Boundary Element Parallel Computation for 3D Elastostatics Using CUDA

2011 ◽  
Author(s):  
Yingjun Wang ◽  
Qifu Wang ◽  
Gang Wang ◽  
Yunbao Huang ◽  
Yixiong Wei
Keyword(s):  
Boundary Element ◽  
Parallel Computation ◽  
Computer Aided Design ◽  
Graphics Processing Unit ◽  
Computation Method ◽  
Processing Unit ◽  
Element Analysis ◽  
Integral Methods ◽  
Cad Models ◽  
Element Method

Finite Element Method (FEM) is pervasively used in most of 3D elastostatic numerical simulations, in which Computer Aided Design (CAD) models need to be converted into mesh models first and then enriched with semantic data (e.g. material parameters, boundary conditions). The interaction between CAD models and FEM models stated above is very intensive. Boundary Element Method (BEM) has been used gradually instead of FEM in recent years because of its advantage in meshing. BEM can reduce the dimensionality of the problem by one so that the complexity in mesh generation can be decreased greatly. In this paper, we present a Boundary Element parallel computation method for 3D elastostatics. The parallel computation runs on Graphics Processing Unit (GPU) using Computing Unified Device Architecture (CUDA). Three major components are included in such method: (1) BEM theory in 3D elastostatics and the boundary element coefficient integral methods, (2) the parallel BEM algorithm using CUDA, and (3) comparison the parallel BEM using CUDA with conventional BEM and FEM respectively by examples. The dimension reduction characteristics of BEM can dispose the 3D elastostatic problem by 2D meshes, therefore we develop a new faceting function to make the ACIS facet meshes suitable for Boundary Element Analysis (BEA). The examples show that the GPU parallel algorithm in this paper can accelerate BEM computation about 40 times.

A Dual Environment for 3D Modeling With User-Defined Free Form Features

2007 ◽  
Author(s):  
Thomas R. Langerak ◽  
Joris S. M. Vergeest
Keyword(s):  
Computer Aided Design ◽  
Shape Representation ◽  
Target Surface ◽  
Free Form ◽  
Dynamic Feature ◽  
Cad Models ◽  
Form Features ◽  
Definition Of ◽  
High Level ◽  
Aided Design

Modeling with free form features has become the standard in Computer-Aided Design (CAD). With the increasing complexity of free form CAD models, features offer a high-level approach to modeling shapes. However, in most commercial modeling packages, only a static set of free form features is available. Researchers have tried to solve this problem by coming up with methods for user-driven free form feature definition, but failed to connect their methods to a means to instantiate these user-driven free form features on a target surface. Reversely, researchers have proposed tools for modeling with free form features, but these methods are time-intensive in that they are as of yet unsuitable for pre-defined features. This paper presents a new method for user-driven feature definition, as well as a method to instantiate these user-defined features on a target surface. We propose the concept of a dual environment, in which the definition of a feature is maintained simultaneously with its instance on a target surface, allowing the user to modify the definition of an already instantiated feature. This dual environment enables dynamic feature modeling, in which the user is able to change the definition of instantiated features on-the-fly. Furthermore, the proposed instantiation method is independent from the type of shape representation of the target surface and thereby increases the applicability of the method. The paper includes an extensive application example and discusses the results and shortcomings of the proposed methods.

Using CAD Models and Their Semantics to Prepare F.E. Simulations

2005 ◽  
Author(s):  
Okba Hamri ◽  
Jean-Claude Le´on ◽  
Franca Giannini ◽  
Bianca Falcidieno
Keyword(s):  
Finite Element ◽  
Data Structure ◽  
Computer Aided Design ◽  
Simulation Models ◽  
Product Model ◽  
Element Analysis ◽  
Time Model ◽  
Usual Practice ◽  
Shape Adaptation ◽  
Cad Models

The preparation of simulation models from Computer Aided Design (CAD) models is still a difficult task since shape changes are often required to adapt a component or a mechanical system to the hypotheses and specifications of the simulation model. Detail removal or idealization operations are among the current treatments performed during the preparation of simulation models. Most of the time, model exchanges are required between the engineering office and the simulation engineers, often producing losses of information and lacking of robustness. Thus, inefficient processes and remodelling phases form the usual practice. In this paper we show that geometric models can be extracted from CAD software as well as some of their semantics. This semantics can then be transferred, used and eventually preserved during the shape adaptation process required for a given Finite Element Analysis (FEA). The software environment enabling this transfer simultaneously requires the description of the initial B-Rep NURBS model as well as that of the adapted one. The process set up is based on STandard for the Exchange of Product model data (STEP) to provide a robust link between CAD and shape adaptation environments. In order to describe the appropriate variety of shapes required for the Finite Element (FE) preparation, a specific data structure is proposed to express the corresponding topology of the models. Hence, it is shown that the operators associated to the FE preparation process can take advantage of this data structure and the semantics of the initial CAD model that can be attached to the adapted model. Examples illustrating the various process steps and corresponding operations are provided and demonstrate the robustness of the approach.

scholarly journals Application of process mapping for digitization of mechanical parts with 3D laser scanner

2018 ◽  
Vol 9 ◽  
pp. 11 ◽  
Author(s):  
Antonio Piratelli-Filho ◽  
Alberto José Alvares ◽  
Rosenda Valdés Arencibia
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Mapping Method ◽  
Free Form ◽  
Process Mapping ◽  
Mechanical Parts ◽  
Cad Models ◽  
Measurement Planning ◽  
Aided Design

This work presents a systematization method for digitization of mechanical parts with three-dimensional (3D) laser scanner using the process mapping method. The application involves the use of the IDEFØ methodology of process mapping to address the sequence of steps required to obtain the computer-aided design (CAD) model of the measured part. The variables involved in the setup and measurement with 3D laser scanner were investigated and applied to regular and free-form parts, and the parameter geometry, texture, light reflection and procedure of data acquisition were considered in the analysis. The software commands used to create the CAD models were also included and the ones related to mesh and surface creation were detailed. The systematized measurement planning was graphi graphically presented, and it proved useful to operators during the digitization process.

CAD Model Segmentation Via Deep Learning

2020 ◽  
pp. 2041005
Author(s):  
Antoine Van Biesbroeck ◽  
Feifei Shang ◽  
David Bassir
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Computer Aided Design ◽  
Mapping Method ◽  
Learning Technologies ◽  
Cad Model ◽  
Element Analysis ◽  
Novel Approach ◽  
Computer Aided ◽  
Cad Models

Computer aided design (CAD) models are widely employed in the current computer aided engineering or finite element analysis (FEA) systems that necessitate an optimal meshing as a function of their geometry. To this effect, the sub-mapping method is advantageous, as it segments the CAD model into different sub-parts, with the aim mesh them independently. Many of the existing 3D shape segmentation methods in literature are not suited to CAD models. Therefore, we propose a novel approach for the segmentation of CAD models by harnessing deep learning technologies. First, we refined the model and extracted local geometric features from its shape. Subsequently, we devised a convolutional neural network (CNN)-inspired neural network trained with a custom dataset. Experimental results demonstrate the robustness of our approach and its potential to adapt to augmented datasets in future.

scholarly journals Online Design

2000 ◽  
Vol 122 (03) ◽  
pp. 68-72
Author(s):  
Jean Thilmany
Keyword(s):  
Computer Aided Design ◽  
High Speed ◽  
Personal Computers ◽  
Element Analysis ◽  
Mathematical Application ◽  
Design Engineers ◽  
Similar Work ◽  
Cad Models ◽  
Computer Based ◽  
Aided Design

This article discusses that computer-based technologies have greatly influenced the way design engineers work. The first technological innovation was the use of high-powered personal computers. With PCs, engineers had access to high-speed applications of computer-aided design software right at their own desks. Personal computers took the place of rulers and pencils. The second innovation, he said, is the advancing capability of PCs to function as supercomputers, crunching numbers much faster than formerly possible. By taking advantage of this technology, engineers untrained in a mathematical application such as finite element analysis can run an FEA software program that performs calculations automatically and will shave weeks off the design process. Hothouse uses the Spatial technology to repair CAD models brought in from outside sources and to translate CAD files the company sends to its suppliers, collaborators, and clients. Before Hothouse began sending CAD files to the online service, company employees spent days repairing or rebuilding files on their own. Sometimes suppliers or clients that received Hothouse CAD files had to do similar work on their end.

A Topological Model for the Representation of Meshing Constraints in the Context of Finite Element Analysis

2006 ◽  
Author(s):  
Gilles Foucault ◽  
Jean-Claude Le´on ◽  
Jean-Christophe Cuillie`re ◽  
Vincent Franc¸ois ◽  
Roland Maranzana
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Computer Aided Design ◽  
Boundary Representation ◽  
Fe Model ◽  
Element Analysis ◽  
Element Size ◽  
Cad Models ◽  
High Level ◽  
Meshing Process

The preparation of Finite Element analysis models (FE models) from Computer Aided Design (CAD) models is still a difficult task since its Boundary Representation (B-Rep) is often composed of a large number of thin faces, small edges, which are much smaller than the desired element size, and are not relevant for the meshing process. Such inconsistencies often cause poor-shaped FE elements, overdensities of elements, not only slowing down the computation of the FE solution, but also producing poor simulation results. In this paper, we present a “Mesh Constraint Topology” (MCT) model with adaptation operators aiming at transforming the CAD model in a FE model which only contains meshing-relevant edges and vertices, i.e. the explicit model of data intrinsic to the meshing process. Because the topology of faces adapted for meshing could contain interior edges, the MCT is represented with adjacency graphs instead of the B-Rep data-structure. We demonstrate how graphs provide efficient schemes to qualify interior and boundary entities, and facilitate the design of adaptation operators using high-level graph operators. Application and results are presented through adaptation issues of CAD models solved using MCT adaptation operators.

Force-Enabled Sculpting of CAD Models

2000 ◽  
Author(s):  
Pietro Buttolo ◽  
Paul Stewart ◽  
Yifan Chen
Keyword(s):  
Computer Aided Design ◽  
Free Form ◽  
Design Models ◽  
Trade Off ◽  
Cartesian Space ◽  
Computer Aided ◽  
Cad Models ◽  
Geometrical Information ◽  
Aided Design ◽  
Free Form Surfaces

Abstract Transferring geometrical information between Computer-Aided Design models and physical prototypes is a time-intensive task and as such is one of the critical bottlenecks in the automotive design process. Sculpting of free-form surfaces in force enabled CAD applications could bridge the gap between digital models and certain physical prototypes. In this paper a novel force-enabled surface manipulation method called stick-to-surface/stick-to-pen is presented. During sculpting, the haptic device is constrained to follow the virtual surface, and simultaneously the surface is controlled to follow the device. The trade-off between which follows which is managed by partitioning the Cartesian space into a browsing subspace and a manipulation subspace.

Computer-Aided Design, Manufacturing, and Modeling of Polymer Scaffolds for Tissue Engineering

2005 ◽  
Author(s):  
James J.-S. Stone ◽  
Andrew R. Thoreson ◽  
Kurt L. Langner ◽  
Jay M. Norton ◽  
Daniel J. Stone ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Computer Aided Design ◽  
Material Selection ◽  
Polymer Scaffolds ◽  
Servo Motor ◽  
Element Analysis ◽  
Computer Aided ◽  
Different Temperatures ◽  
Cad Models ◽  
Aided Design

A custom computer-controlled rapid prototyping system was designed and developed in this research. This system for bio-manufacturing of polymer scaffolds included 3D motion control components, a nozzle, a pressure controller, and a temperature-controlled reservoir containing a biomaterial. Heating elements built into the reservoir melted the biomaterial. The pressure line attached to the reservoir provided a controllable force that extruded the polymer biomaterial through the nozzle and deposited the polymer biomaterial onto a platform to fabricate scaffolds. A low pressure (830 KPa) system was designed and fabricated to accommodate different temperatures, motion speeds, and viscosities of polymer biomaterials. The reservoir with the nozzle was mounted to servo motor-controlled linear x-y motion devices along with a third servo motor-controlled device that controlled the z-position of the platform. Poly(ε-caprolactone) [PCL] was used to fabricate scaffolds with designed structure that were used in cell and tissue regeneration studies. 3D computer-aided design (CAD) with Pro-Engineer and computational finite element analysis (FEA) programs with MSC_Patran and MSC_Marc were used to model scaffold designs with appropriate architecture and material selection. The CAD models were used in FEA to develop new methods for determining mechanical properties of tissue scaffolds of desired structure and geometry. FEA models were validated by mechanical testing and other published results. Technology developed in this research has potential for the advancement of bio-manufacturing, and design optimization of scaffolds for tissue engineering.

scholarly journals An isogeometric b-rep mortar-based mapping method for non-matching grids in fluid-structure interaction

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Andreas Apostolatos ◽  
Altuğ Emiroğlu ◽  
Shahrokh Shayegan ◽  
Fabien Péan ◽  
Kai-Uwe Bletzinger ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Fluid Structure Interaction ◽  
Mapping Method ◽  
Boundary Representation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Discrete Surface ◽  
Cad Models ◽  
Volume Method ◽  
Aided Design

AbstractIn this study the isogeometric B-Rep mortar-based mapping method for geometry models stemming directly from Computer-Aided Design (CAD) is systematically augmented and applied to partitioned Fluid-Structure Interaction (FSI) simulations. Thus, the newly proposed methodology is applied to geometries described by their Boundary Representation (B-Rep) in terms of trimmed multipatch Non-Uniform Rational B-Spline (NURBS) discretizations as standard in modern CAD. The proposed isogeometric B-Rep mortar-based mapping method is herein extended for the transformation of fields between a B-Rep model and a low order discrete surface representation of the geometry which typically results when the Finite Volume Method (FVM) or the Finite Element Method (FEM) are employed. This enables the transformation of such fields as tractions and displacements along the FSI interface when Isogeometric B-Rep Analysis (IBRA) is used for the structural discretization and the FVM is used for the fluid discretization. The latter allows for diverse discretization schemes between the structural and the fluid Boundary Value Problem (BVP), taking into consideration the special properties of each BVP separately while the constraints along the FSI interface are satisfied in an iterative manner within partitioned FSI. The proposed methodology can be exploited in FSI problems with an IBRA structural discretization or to FSI problems with a standard FEM structural discretization in the frame of the Exact Coupling Layer (ECL) where the interface fields are smoothed using the underlying B-Rep parametrization, thus taking advantage of the smoothness that the NURBS basis functions offer. All new developments are systematically investigated and demonstrated by FSI problems with lightweight structures whereby the underlying geometric parametrizations are directly taken from real-world CAD models, thus extending IBRA into coupled problems of the FSI type.

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