Computer-Aided Design最新文献_第2页

Point containment algorithms for constructive solid geometry with unbounded primitives 无界基元构造实体几何的点包含算法

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-09-11 DOI: 10.1016/j.cad.2024.103803

Paul K. Romano , Patrick A. Myers , Seth R. Johnson , Aljaz̆ Kols̆ek , Patrick C. Shriwise

{"title":"Point containment algorithms for constructive solid geometry with unbounded primitives","authors":"Paul K. Romano , Patrick A. Myers , Seth R. Johnson , Aljaz̆ Kols̆ek , Patrick C. Shriwise","doi":"10.1016/j.cad.2024.103803","DOIUrl":"10.1016/j.cad.2024.103803","url":null,"abstract":"<div><p>We present several algorithms for evaluating point containment in constructive solid geometry (CSG) trees with unbounded primitives. Three algorithms are presented based on postfix, prefix, and infix notations of the CSG binary expression tree. We show that prefix and infix notations enable short-circuiting logic, which reduces the number of primitives that must be checked during point containment. To evaluate the performance of the algorithms, each algorithm was implemented in the OpenMC Monte Carlo particle transport code, which relies on CSG to represent solid bodies through which subatomic particles travel. Two sets of tests were carried out. First, the execution time to generate a rasterized image of a 2D slice of three CSG models of varying complexity was measured. Use of both prefix and infix notations offered significant speedup over the postfix notation that has traditionally been used in particle transport codes, with infix resulting in a 6<span><math><mo>×</mo></math></span> reduction in execution time relative to postfix for a model of a tokamak fusion device. We then measured the execution time of neutron transport simulations of the same three models using each of the algorithms. The results and performance improvements reveal the same trends as for the rasterization test, with a 5.52<span><math><mo>×</mo></math></span> overall speedup using the infix notation relative to the original postfix notation in OpenMC for the tokamak model.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010448524001301/pdfft?md5=8fddc42a59401cae480fb7d7905061a3&pid=1-s2.0-S0010448524001301-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tessellation and interactive visualization of four-dimensional spacetime geometries 四维时空几何图形的细分和交互式可视化

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-08-24 DOI: 10.1016/j.cad.2024.103792

Philip Claude Caplan

{"title":"Tessellation and interactive visualization of four-dimensional spacetime geometries","authors":"Philip Claude Caplan","doi":"10.1016/j.cad.2024.103792","DOIUrl":"10.1016/j.cad.2024.103792","url":null,"abstract":"<div><p>This paper addresses two problems needed to support four-dimensional (<span><math><mrow><mn>3</mn><mi>d</mi><mo>+</mo><mi>t</mi></mrow></math></span>) spacetime numerical simulations. The first contribution is a general algorithm for producing conforming spacetime meshes of moving geometries. Here, the surface points of the geometry are embedded in a four-dimensional space as the geometry moves in time. The geometry is first tessellated at prescribed time steps and then these tessellations are connected in the parameter space of each geometry entity to form tetrahedra. In contrast to previous work, this approach allows the resolution of the geometry to be controlled at each time step. The only restriction on the algorithm is the requirement that no topological changes to the geometry are made (i.e. the hierarchical relations between all geometry entities are maintained) as the geometry moves in time. The validity of the final mesh topology is verified by ensuring the tetrahedralizations represent a closed 3-manifold. For some analytic problems, the <span><math><mrow><mn>4</mn><mi>d</mi></mrow></math></span> volume of the tetrahedralization is also verified. The second problem addressed in this paper is the design of a system to interactively visualize four-dimensional meshes when the <span><math><mrow><mn>4</mn><mi>d</mi></mrow></math></span> view changes, including tetrahedra (embedded in <span><math><mrow><mn>4</mn><mi>d</mi></mrow></math></span>) and pentatopes. Algorithms that either include or exclude a geometry shader are described, and the efficiency of each approach is then compared. Overall, the results suggest that visualizing tetrahedra (either those bounding the domain, or extracted from a pentatopal mesh) using a geometry shader achieves the highest frame rate, realizing interactive frame rates of at least 15 frames per second for meshes with about 50 million tetrahedra.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010448524001192/pdfft?md5=e51e1de5cf978ffc80f6145b0ad55e2e&pid=1-s2.0-S0010448524001192-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142117737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Topology-aware blending method for implicit heterogeneous porous model design 用于隐式异质多孔模型设计的拓扑感知混合法

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-08-08 DOI: 10.1016/j.cad.2024.103782

Depeng Gao, Yang Gao, Yuanzhi Zhang, Hongwei Lin

{"title":"Topology-aware blending method for implicit heterogeneous porous model design","authors":"Depeng Gao, Yang Gao, Yuanzhi Zhang, Hongwei Lin","doi":"10.1016/j.cad.2024.103782","DOIUrl":"10.1016/j.cad.2024.103782","url":null,"abstract":"<div><p>Porous structures are materials consisting of minuscule pores, where the microstructure morphology significantly impacts their macroscopic properties. Integrating different porous structures through a blending method is indispensable to cater to diverse functional regions in heterogeneous models. Previous studies on blending methods for porous structures have mainly focused on controlling the shape of blending regions, yet they have fallen short in effectively addressing topological errors in blended structures. This paper introduces a new blending method that successfully addresses this issue. Initially, a novel initialization method is proposed, which includes distinct strategies for blending regions of varying complexities. Subsequently, we formulate the challenge of eliminating topological errors as an optimization problem based on persistent homology. Through iterative updates of control coefficients, this optimization problem is solved to generate a blended porous structure. Our approach not only avoids topological errors but also governs the shape and positioning of the blending region while remaining unchanged in the structure outside blending region. The experimental outcomes validate the effectiveness of our method in producing high-quality blended porous structures. Furthermore, these results highlight potential applications of our blending method in biomimetics and the design of high-stiffness mechanical heterogeneous models.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Handlebody Plesiohedra Unchained: Topologically Interlocked Cell-Transitive 3-Honeycombs 解锁的手体 Plesiohedra：拓扑互锁细胞传递 3-蜂巢

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-08-08 DOI: 10.1016/j.cad.2024.103779

Matthew Ebert , Doyeon Kim , Ergun Akleman , Vinayak Krishnamurthy

{"title":"Handlebody Plesiohedra Unchained: Topologically Interlocked Cell-Transitive 3-Honeycombs","authors":"Matthew Ebert , Doyeon Kim , Ergun Akleman , Vinayak Krishnamurthy","doi":"10.1016/j.cad.2024.103779","DOIUrl":"10.1016/j.cad.2024.103779","url":null,"abstract":"<div><p>We present an approach for systematic design of generalized Plesiohedra, a new type of 3D space-filling shapes that can even include unchained handlebodies. We call these handlebody plesiohedra unchained, since they are <strong>topologically interlocked</strong>, i.e., they can be assembled and disassembled without breaking any of the solids apart and they can keep in place with a set of boundary constraints. These space-filling shapes (i.e. congruent prototiles) are obtained from the Voronoi decomposition of symmetric Delone (Delaunay) point sets. To create this new class of shapes, we generalize the design space of classical Plesiohedra by introducing two novel geometric steps: (a) extension of point sites to piecewise linear approximations of higher-dimensional geometries and (b) extension of symmetries to 3D crystallographic symmetries. We show how these specific collections of higher-dimensional geometries can admit the symmetric Delone property. A Voronoi partitioning of 3D space using these specific collections of higher-dimensional shapes as Voronoi sites naturally results in congruent prototiles. This generalizes the idea of classical Plesiohedra by allowing for piecewise linear approximation of curved edges and faces, non-convex boundaries, and even handlebodies with positive genus boundaries to provide truly volumetric material systems in contrast to traditional planar or shell-like systems. To demonstrate existence of these solid shapes, we produced a large set of unchained congruent space-filling handlebodies as proofs of concept. For this, we focused our investigation using isometries of some space-filling polyhedra, such as a cube and a truncated octahedron with circles, and curve complexes as Voronoi sites. These results point to a rich and vast parametric design space of unchained handlebody plesiohedra making them an excellent representations for engineering applications such as topologically interlocked architectured materials.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141964515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimum design of uniform and non-uniform infill-coated structures with discrete variables 具有离散变量的均匀和非均匀灌注涂层结构的优化设计

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-08-05 DOI: 10.1016/j.cad.2024.103781

Alain Garaigordobil, José Antonio Postigo, Rubén Ansola, Javier Canales

{"title":"Optimum design of uniform and non-uniform infill-coated structures with discrete variables","authors":"Alain Garaigordobil, José Antonio Postigo, Rubén Ansola, Javier Canales","doi":"10.1016/j.cad.2024.103781","DOIUrl":"10.1016/j.cad.2024.103781","url":null,"abstract":"<div><p>This article introduces a novel computer-aided procedure to design optimised coated structures with precise shell thickness control using the Smallest Univalue Segment Assimilating Nucleus operator and a novel augmentation-projection technique. Structures with heterogeneous sections, or coated structures, combine two different materials for the nucleus and the shell, which are generally chosen so that the material in the infill is lighter and the material in the coating is stiffer, which in this work are supposed homogeneous. Solving the interface problem requires material properties interpolation equations that consider three material phases, accurate placement of the coating over the base material, and precise control over the coating's thickness. The formation of the coating is controlled by the <em>Smallest Univalue Segment Assimilating Nucleus</em>, an edge detection operator developed in <em>Digital Image Processing</em>. The coating's thickness is controlled by an innovative methodology consisting of the projection of an augmented contour field, which is shown to create a constant thickness coating around the material domain. The optimisation problem is solved with the <em>Sequential Element Rejection and Admission</em> method. The validity of the procedure has been verified by solving various numerical application examples.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010448524001088/pdfft?md5=818e970a6501d02a83f834dc682faba0&pid=1-s2.0-S0010448524001088-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural regularity detection and enhancement for surface mesh reconstruction in reverse engineering 用于逆向工程中曲面网格重建的结构规整性检测与增强

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-08-02 DOI: 10.1016/j.cad.2024.103780

Anyu Mu, Zhenyu Liu, Guifang Duan, Jianrong Tan

{"title":"Structural regularity detection and enhancement for surface mesh reconstruction in reverse engineering","authors":"Anyu Mu, Zhenyu Liu, Guifang Duan, Jianrong Tan","doi":"10.1016/j.cad.2024.103780","DOIUrl":"10.1016/j.cad.2024.103780","url":null,"abstract":"<div><p>Recovering geometric regularities from scanned mesh models with various types of surface features has always been a challenging task in reverse engineering. To address this problem, this paper presents a regularity detection and enhancement framework for surface mesh reconstruction. Initially, surface patches are identified by decomposing the original model into planar, quadric and freeform surface patches. Similar surface patches are aligned with each other by pairwise registration, and symmetry patterns are detected from the accumulated affine transformations using an improved grid fitting method. Regular relations between symmetry patterns and individual surface patches are enumerated and progressively strengthened by orientation, dimension and placement optimizations. Finally, the resultant model with enhanced regularities is obtained by projecting surface patches onto the optimized parametric surfaces iteratively. Comparative experiments on test models demonstrate that the proposed method outperforms existing methods in recovering both lower- and higher-level regularities of engineering models, especially those with freeform surfaces.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mesh Denoising of Developable Surfaces with Curved Foldings 带曲线折叠的可展开曲面的网格去噪

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-07-29 DOI: 10.1016/j.cad.2024.103776

Jiale Pan, Pengbo Bo, Yifeng Li, Zhongquan Wang

引用次数: 0

Design methodology of functionally graded cellular materials: Manipulating design parameters of triply periodic minimal surfaces through three-dimensional density distributions 功能分级蜂窝材料的设计方法：通过三维密度分布操纵三重周期极小曲面的设计参数

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-07-24 DOI: 10.1016/j.cad.2024.103778

Emilio A. Ramírez , Nicolas Béraud , Franck Pourroy , François Villeneuve , Jorge L. Amaya , Matthieu Museau

{"title":"Design methodology of functionally graded cellular materials: Manipulating design parameters of triply periodic minimal surfaces through three-dimensional density distributions","authors":"Emilio A. Ramírez , Nicolas Béraud , Franck Pourroy , François Villeneuve , Jorge L. Amaya , Matthieu Museau","doi":"10.1016/j.cad.2024.103778","DOIUrl":"10.1016/j.cad.2024.103778","url":null,"abstract":"<div><p>Functionally Graded Cellular Materials (FGCM) with variable volume fractions have demonstrated significant advantages, including weight reduction, improved stiffness, and enhanced load distribution, when compared to uniform density counterparts. Their design is often characterized by the application of a density distribution to locally modify Representative Volume Elements (RVEs). Current studies have explored the application of Triply Periodic Minimal Surfaces (TPMS) topologies, given their capability to create seamless and interconnected structures, thus avoiding stress concentration issues commonly encountered in traditional lattice configurations. Consequently, this paper introduces a design methodology tailored to TPMS-based FGCM allowing for independent or simultaneous adjustments of RVE thickness and size. Models for predicting relative density as a function of the RVE design parameters of Primitive and Gyroid topologies are presented and discussed. These models are employed to adapt the topologies to three-dimensional density distributions. The proposed method is implemented as a set of design tools and is illustrated for the studied TPMS topologies.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141850732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Generalizing feature preservation in iso-surface extraction from triple dexel models 在从三重 dexel 模型中提取等值面时实现特征保存的通用化

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-07-24 DOI: 10.1016/j.cad.2024.103777

Tobias Schleifstein , Arne Lorenz , Svenja Schalthöfer , Denys Plakhotnik , Leif Kobbelt

引用次数: 0

Density-Based Isogeometric Topology Optimization of Shell Structures 基于密度的壳体结构等几何拓扑优化

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-07-22 DOI: 10.1016/j.cad.2024.103773

Qiong Pan, Xiaoya Zhai, Falai Chen

{"title":"Density-Based Isogeometric Topology Optimization of Shell Structures","authors":"Qiong Pan, Xiaoya Zhai, Falai Chen","doi":"10.1016/j.cad.2024.103773","DOIUrl":"10.1016/j.cad.2024.103773","url":null,"abstract":"<div><p>Shell structures with high stiffness-to-weight ratios are desirable in various engineering applications. Topology optimization serves as a popular and effective tool for generating optimal shell structures. The solid isotropic material with penalization (SIMP) method is often chosen because of its simplicity and convenience. However, SIMP method is typically integrated with conventional Finite Element Analysis (FEA) which has limitations in computational accuracy. Achieving high accuracy with FEA necessitates a substantial number of elements, leading to computational burdens. In addition, the discrete representation of the material distribution function may result in rough boundaries. Owing to these limitations, this paper proposes an Isogeometric Analysis (IGA) based SIMP method for optimizing the topology of shell structures based on Reissner–Mindlin theory. This method uses Non-Uniform Rational B-Splines (NURBS) to represent both the shell structure and the material distribution function with the same basis functions, allowing for higher accuracy and smoother boundaries. The optimization model takes compliance as the objective function with a volume fraction constraint and the coefficients of the density function as design variables, resulting in an optimized shell structure defined by the material distribution function. To obtain fairing boundaries of the holes in the optimized shell structure, further process is conducted by fitting the boundaries with fair B-spline curves automatically. Furthermore, the proposed IGA-SIMP framework is applied to generate porous shell structures by imposing different local volume fraction constraints. Numerical examples are provided to demonstrate the feasibility and efficiency of the IGA-SIMP method, showing that it outperforms the FEA-SIMP method and produces smoother boundaries.</p></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141960451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0