scholarly journals Surface reconstruction from FE mesh model

2018 ◽  
Vol 6 (2) ◽  
pp. 197-208 ◽  
Author(s):  
Jung Min Park ◽  
Byung Chai Lee ◽  
Soo Won Chae ◽  
Ki Youn Kwon
Keyword(s):  
Finite Element ◽  
Finite Element Mesh ◽  
Design Stage ◽  
Free Form ◽  
Surface Model ◽  
Element Analysis ◽  
Element Mesh ◽  
Design Modification ◽  
B Spline ◽  
Mesh Model

Abstract In the computer aided engineering process with finite element analysis, a CAD surface model is sometimes needed for various tasks such as remeshing, shape optimization or design modification. Occasionally, engineers who perform an analysis at the product design stage are given only finite element mesh models; corresponding CAD models can be unavailable. This paper presents a method to extract free-form B-spline surfaces and certain feature curves from a surface mesh model. First, using the k-means clustering method, our process segments given meshes into a number of regions according to principal curvature information; then, region operations are performed. Next, each region is converted to an approximately free-form B-spline surface. In the last step, feature curves to create loft or sweep surfaces are calculated by minimizing the distance error. Some practical examples are also presented to demonstrate the effectiveness and usefulness of our method. Highlights We propose a new method of creating CAD surfaces from given finite element mesh model. Feature curves are extracted for creating sweep or loft surfaces. By using the generated surfaces based on the feature curves, the shape modification can be easily performed in the designing process.

Finite Element Mesh Generator Applying Constraints’ Propagation and Isoparametric Mapping

1991 ◽  
Author(s):  
J. Rodriguez ◽  
M. Him
Keyword(s):  
Finite Element ◽  
Mesh Generation ◽  
Element Model ◽  
Finite Element Mesh ◽  
Fe Model ◽  
Element Analysis ◽  
Element Mesh ◽  
Mesh Generator ◽  
Generation Algorithm ◽  
Essential Input

Abstract This paper presents a finite element mesh generation algorithm (PREPAT) designed to automatically discretize two-dimensional domains. The mesh generation algorithm is a mapping scheme which creates a uniform isoparametric FE model based on a pre-partitioned domain of the component. The proposed algorithm provides a faster and more accurate tool in the pre-processing phase of a Finite Element Analysis (FEA). A primary goal of the developed mesh generator is to create a finite element model requiring only essential input from the analyst. As a result, the generator code utilizes only a sketch, based on geometric primitives, and information relating to loading/boundary conditions. These conditions represents the constraints that are propagated throughout the model and the available finite elements are uniformly mapped in the resulting sub-domains. Relative advantages and limitations of the mesh generator are discussed. Examples are presented to illustrate the accuracy, efficiency and applicability of PREPAT.

Automatical Reconstruction of Deficient CAD Model

2011 ◽  
Vol 186 ◽  
pp. 241-245 ◽  
Author(s):  
Gui Ping Qian ◽  
Ruo Feng Tong
Keyword(s):  
Finite Element ◽  
Complex Surface ◽  
Finite Element Mesh ◽  
Surface Model ◽  
Reconstruction Method ◽  
Cad Model ◽  
Element Mesh ◽  
Surface Patches ◽  
Topological Errors ◽  
Surface Representations

This paper presents a new CAD model reconstruction method for finite element mesh analysis. It has been accepted by many researchers that modification of a model is often a necessity as a precursor to effective mesh generation. We design an IGES surface model transformation and repairing method based on trimmed B-spline surface patches, and give an algorithm for reconstructing Brep model from surface model without correct topology information. In processing Brep model for numerical simulation, the critical issues involves the rectification of geometrical and topological errors, clearing up sharp edges and cracks, geometry healing will be emphasized. Our model-healing algorithm essentially simplifies the problems of the imperfect models and allows one to deal with simple surface model rather than complex surface representations for finite element mesh.

Reducing Dynamic Response Variation Using NURBS Finite Element-Based Geometry Perturbation

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
K. Zhou ◽  
J. Tang
Keyword(s):  
Finite Element ◽  
Design Optimization ◽  
Finite Element Mesh ◽  
Dynamic Responses ◽  
Robust Design Optimization ◽  
Design Parameters ◽  
Surface Geometry ◽  
Element Mesh ◽  
Design Modification ◽  
Response Variation

The uncertainties in real structures usually lead to variations in their dynamic responses. In order to reduce the likelihood of unexpected failures in structures, it is necessary to reduce the response variations. Among various design manipulations, the modification of surface geometry could be a viable option to achieve performance robustness against uncertainties. However, such design modification is difficult to achieve based on conventional finite element methods, primarily due to the inevitable discrepancy between the conventional finite element mesh and the corresponding surface geometry. This issue may become even more severe in design optimization, as an optimized mesh based on conventional finite element analysis may yield nonsmooth surface geometry. In this research, we adopt the nonuniform rational B-splines (NURBS) finite element method to facilitate the robust design optimization (RDO), where the fundamental advantage is that the NURBS finite element mesh is conformal to the underlying NURBS geometry. Furthermore, this conformal feature ensures that, upon finite element-based optimization, the resulting surface geometry is smooth. Taking advantage of that both the uncertainties and the design modifications are small, we formulate a sensitivity-based algorithm to rapidly evaluate the response variations. Based on the direct relation between the response variations and design parameters, the optimal surface geometry that yields the minimal response variation can be identified. Systematic case analyses are carried out to validate the effectiveness and efficiency of the proposed approach.

Finite Element Analysis Using Uniform B-Spline Basis

2008 ◽  
Author(s):  
Ashok V. Kumar ◽  
Ravi K. Burla
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Curve Surface ◽  
Stress And Strain ◽  
Element Analysis ◽  
Element Mesh ◽  
B Spline ◽  
Structured Grids ◽  
Spline Basis ◽  
Element Method

Implicit boundary finite element method uses structured grids for analysis instead of a conforming finite element mesh. The geometry of the structure is represented independently using curve / surface equations. These equations are used to apply boundary conditions even though there may not be nodes available on the boundary. In this paper, this method is applied for analysis using uniform B-spline basis defined over structured grids. Solutions can be constructed that are C1 or C2 continuous throughout the analysis domain using B-spline basis functions. Therefore, the computed stress and strain are continuous in the analysis domain thus eliminating the need for smoothing stress/strain results. Compared to conforming mesh, it is easier to generate structured grids that overlap the geometry and the elements in the grid are regular shaped and undistorted. Numerical examples are presented to demonstrate the performance of these B-spline elements. The results are compared with analytical solutions as well as traditional finite element solutions. Convergence studies for several examples show that B-spline elements provide accurate solutions with fewer elements and nodes as compared to traditional finite element method (FEM).

scholarly journals Coupling Finite Element and Mesh-free Methods for Modelling Brain Deformation in Response to Tumour Growth

2008 ◽  
Author(s):  
Jamie Berger ◽  
Asley Horton ◽  
Grand roman Joldes ◽  
Adam Wittek ◽  
Karol Miller
Keyword(s):  
Finite Element ◽  
Tumour Growth ◽  
Finite Element Mesh ◽  
Element Analysis ◽  
Element Mesh ◽  
High Deformation ◽  
Brain Deformation ◽  
Mesh Free ◽  
Mesh Free Methods ◽  
The Brain

Very little is known about the deformation effects of tumour growth within the brain. Computer simulations have the potential to calculate such deformations. A method for computing localised high deformations within the brain’s soft tissue is presented. Such knowledge would be significant towards neuroscience and neurosurgery, particularly for quantifying tumour aggressiveness, therapy planning, as well as surgical planning and simulation. A Finite Element mesh used in the vicinity of a growing tumour is very quickly destroyed and cannot be used reliably unless complicated automatic re-meshing exists. Mesh-free methods are capable of handling much larger deformations, however are known to be less reliable that Finite Element analysis for moderate deformations. A mixed-mesh approach utilises mesh-free regions within localised high-deformation zones, with the remaining model comprised of a Finite Element mesh. In this study, a new algorithm is proposed coupling the Finite Element and Element Free Galerkin methods for use in applications of high localised deformation, such as brain tumour growth. The algorithm is verified against a number of separate Finite Element and mesh-free problems solved via validated/commercial software. Maximum errors of less than 0.85 mm were maintained, corresponding to the working resolution of an MRI scan. A mixed-mesh brain model is analysed with respect to different tumour growth volumes located behind the left ventricle. Significant displacements of up to 9.66 mm surrounding a 4118 mm3 sized tumour are noted, with 14.5% of the brain mesh suffering deformation greater than 5 mm.

Sign in / Sign up

Export Citation Format

Share Document