Computer-Aided Design最新文献

Plate Manufacturing Constraint in Topology Optimization Using Anisotropic Filter 利用各向异性滤波器优化拓扑结构中的板材制造约束

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-11-23 DOI: 10.1016/j.cad.2024.103823

Yuji Wada , Tokimasa Shimada , Koji Nishiguchi , Shigenobu Okazawa , Makoto Tsubokura

{"title":"Plate Manufacturing Constraint in Topology Optimization Using Anisotropic Filter","authors":"Yuji Wada , Tokimasa Shimada , Koji Nishiguchi , Shigenobu Okazawa , Makoto Tsubokura","doi":"10.1016/j.cad.2024.103823","DOIUrl":"10.1016/j.cad.2024.103823","url":null,"abstract":"<div><div>The manufacturing constraint of topology optimization for finding structures composed primarily of plate cross sections with an automatically decided surface normal is discussed. The anisotropic partial differential equation filter for the sensitivity of the objective function is designed such that the eigenvalue-resolved stress tensor is converted to the anisotropic filter tensor. The user can obtain an optimal shape proposal with different degrees of plate formation by changing the influence radius of the ellipsoidal filter. Plate structure formation and stiffness compliance performance are discussed through three sample problems: a solid bar subjected to torsional loads, an L-shaped member subjected to multiple loads, and a vehicle body frame intended to be a complex frame. The finite element analysis with 3–300 million degrees of freedom is required to form a shell plate structure from a large ingot with a volume fraction constraint of 1%–5%. A voxel topology optimization software that utilizes the building cube method framework available in massively parallel environments is developed, and the parallel performance of the optimization routine, including the plate filtering, is measured.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"180 ","pages":"Article 103823"},"PeriodicalIF":3.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722617","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

Fast algorithm for extracting domains and regions from three-dimensional triangular surface meshes 从三维三角形曲面网格中提取域和区域的快速算法

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-11-19 DOI: 10.1016/j.cad.2024.103824

Sebastian Bohm, Erich Runge

引用次数: 0

Feature-aware Singularity Structure Optimization for Hex Mesh 六边形网格的特征感知奇点结构优化

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-11-19 DOI: 10.1016/j.cad.2024.103825

Xiaopeng Zheng, Junyi Duan, Na Lei, Zhongxuan Luo

{"title":"Feature-aware Singularity Structure Optimization for Hex Mesh","authors":"Xiaopeng Zheng, Junyi Duan, Na Lei, Zhongxuan Luo","doi":"10.1016/j.cad.2024.103825","DOIUrl":"10.1016/j.cad.2024.103825","url":null,"abstract":"<div><div>Hexahedral (Hex) mesh topology optimization holds significant importance in various engineering and scientific applications. Most of the previous algorithms just use collapse operations in most cases, and less frequently use inflation operations, limited by the flexibility as well as the complexity of inflation operations in complex singularity structures, which restricts efficacy of methods. Furthermore, the singularities from previous optimization methods are located in the interior, which cannot be aligned to the features. In this paper, we verify that sheet collapse and inflation operations are capable of representing all hex mesh topology operations. Moreover, we introduce a feature-aware hex mesh optimization algorithm via sheet operations. The algorithm employs a greedy collapse strategy to simplify singularities, utilizes inflation operations to optimize high-degree singularities, and aligns singularities with feature lines. The sheet inflation algorithm we propose obtains the initial surface from an edge and is capable of generating simple surfaces even in complex topological structures. The experiments demonstrate the superior performance of our algorithm in feature preservation and optimization capability.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"180 ","pages":"Article 103825"},"PeriodicalIF":3.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697679","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

Higher-degrees Hybrid Non-uniform Subdivision Surfaces 更高的混合非均匀细分曲面

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-11-15 DOI: 10.1016/j.cad.2024.103822

Fangyuan Luo, Xin Li

{"title":"Higher-degrees Hybrid Non-uniform Subdivision Surfaces","authors":"Fangyuan Luo, Xin Li","doi":"10.1016/j.cad.2024.103822","DOIUrl":"10.1016/j.cad.2024.103822","url":null,"abstract":"<div><div>Non-Uniform Rational B-splines Surfaces can be defined for any degrees and non-uniform knots, but existing subdivision surfaces are either uniform or of a fixed degree. The only existing non-uniform arbitrary degree subdivision is the scheme in Cashman et al. (2009). However, in order to improve the surface quality, the knot insertion strategy in Cashman et al. (2009) has the problem that the limit surface does not change continuously in terms of the perturbation of knot intervals. This paper solves this problem by introducing higher-degree hybrid non-uniform subdivision surfaces (HNUSS), where the first level refinement converts each valence <span><math><mi>n</mi></math></span> extraordinary point (EP) into a valence <span><math><mi>n</mi></math></span> face (Li et al., 2019). And then, the subdivision scheme can be defined with one step of splitting and several steps of averaging, where most rules are tensor-product of the arbitrary degree B-spline refinement rule with one double knot. We verify that higher-degree HNUSS limit surface is <span><math><msup><mrow><mi>G</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> at the EPs if the knot intervals for the spoke edges of an EP are the same and has a higher order of continuity in other regions. In the absence of multiple knots at EPs, we provide a knot insertion strategy to create a uniform region around an EP. Additionally, numerical experiments show that the limit surface has satisfactory shape quality.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"179 ","pages":"Article 103822"},"PeriodicalIF":3.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699329","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

An Enriched Polyhedral-based Simulation for the Contact Modeling with Form Defects and Mechanical Loads 考虑形状缺陷和机械载荷的接触建模的丰富多面体仿真

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-11-13 DOI: 10.1016/j.cad.2024.103820

Carlos Andrés Restrepo García , Yann Ledoux , Nabil Anwer , Vincent Delos , Laurent Pierre , Denis Teissandier

{"title":"An Enriched Polyhedral-based Simulation for the Contact Modeling with Form Defects and Mechanical Loads","authors":"Carlos Andrés Restrepo García , Yann Ledoux , Nabil Anwer , Vincent Delos , Laurent Pierre , Denis Teissandier","doi":"10.1016/j.cad.2024.103820","DOIUrl":"10.1016/j.cad.2024.103820","url":null,"abstract":"<div><div>Contact modeling is an important activity in the geometrical and tolerancing management. The research on contact modeling using methods based on sets of constraints has focused on the stack-up functions or graph reductions for the accumulation of geometric variations. Even when the Skin Model paradigm is used to simulate form deviations on mating surfaces, the impact of disregarding those deviations has not been formally discriminated. In this paper, an enriched polyhedral-based approach for the contact modeling of mechanisms is proposed. The contact is simulated through a rigid body model with no frictional forces based on the screw theory. In this method, the external loadings on the mechanism are translated into an additional half-space in the polyhedron that imposes an additional restriction to the polyhedron operand. By explicitly including the external mechanical loadings, the impact of the form deviations on a functional condition can be discriminated precisely. In this paper, a case study of a sliding contact between two mating parts of a spectrometer is presented to further illustrate the method advantages.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"180 ","pages":"Article 103820"},"PeriodicalIF":3.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748666","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

Extracting fiber paths from the optimized lamination parameters of variable-stiffness laminated shells based on physic-informed neural network 基于物理信息神经网络从可变刚度层压壳的优化层压参数中提取纤维路径

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-11-01 DOI: 10.1016/j.cad.2024.103821

Xinming Li, Lujie Ma, Bowen Ji, Kuan Fan, Zhengdong Huang

{"title":"Extracting fiber paths from the optimized lamination parameters of variable-stiffness laminated shells based on physic-informed neural network","authors":"Xinming Li, Lujie Ma, Bowen Ji, Kuan Fan, Zhengdong Huang","doi":"10.1016/j.cad.2024.103821","DOIUrl":"10.1016/j.cad.2024.103821","url":null,"abstract":"<div><div>This paper presents a novel approach for extracting fiber paths from the optimized lamination parameters (LPs) of variable stiffness laminated shells, utilizing the framework of physics-informed neural network (PINN). In this methodology, each fiber layer is associated with a specific stream function, which is approximated by an independent neural network. The stream function is governed by a partial differential equation (PDE) derived from the fiber orientation field in the parameter space. Moreover, the isocontours of the stream function are transformed into the actual fiber paths in the physical space. To account for manufacturing constraints, Riemannian geometry serves as a computational tool to determine the intrinsic distance between adjacent fiber paths and the geodesic curvature of the isocontours. By incorporating regularization terms into the loss function based on the physical relationships, the constrained optimization problem is converted into an unconstrained one, making it more suitable for neural network training. Meanwhile, a fiber path extraction (FPE) algorithm is used to minimize the loss function at randomly sampled points through gradient descent. The numerical results suggest that the extraction of fiber paths using PINN can achieve satisfactory levels of accuracy while effectively satisfying the imposed constraints.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"179 ","pages":"Article 103821"},"PeriodicalIF":3.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657976","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

A Hybrid Recognition Framework for Highly Interacting Machining Features Based on Primitive Decomposition, Learning and Reconstruction 基于基元分解、学习和重构的高度交互加工特征混合识别框架

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-11-01 DOI: 10.1016/j.cad.2024.103813

Jianping Yang , Qiaoyun Wu , Yuan Zhang , Jiajia Dai , Jun Wang

{"title":"A Hybrid Recognition Framework for Highly Interacting Machining Features Based on Primitive Decomposition, Learning and Reconstruction","authors":"Jianping Yang , Qiaoyun Wu , Yuan Zhang , Jiajia Dai , Jun Wang","doi":"10.1016/j.cad.2024.103813","DOIUrl":"10.1016/j.cad.2024.103813","url":null,"abstract":"<div><div>For the highly interacting machining features, Layered Projection Decomposition Method presents inferior recognition efficiency and accuracy, due to its high-cost 3D projection and failures in determining projection faces for internal occluded faces. To address these issues, we propose a potential hybrid recognition framework. We first introduce a straightforward adjacent projection wire (APW) over UV wires, automatically restoring the full projection wires from highly interacting features. Building on APWs, an efficient hybrid boundary representation and its corresponding unambiguous primitive definitions are proposed by combining with graph-based boundary representations. Subsequently, we design an efficient primitive decomposition method by introducing primitive boundary matching to decide the initial projection faces, and introducing iterative projection boundary expansion to complete the full primitives from occluded faces. Moreover, we establish an efficient Graph Neural Network to learn the distinguishable distributions over the decomposed primitives. Specifically, an Adjacency Attention Unit is proposed to automatically perceive the influence weight of adjacent nodes, leading to more discriminative self-adaptive shape embedding for efficient primitive recognition. Finally, we summarize convenient reconstruction rules to correct the wrong predictions of feature faces with indistinguishable adjacent relationships. To evaluate the effectiveness of the proposed recognition framework, CAD models of complex aircraft structural parts are collected to present a challenging machining feature dataset. Extensive numerical experiments demonstrate that the proposed hybrid recognition framework enables significant improvements over the state-of-the-art machining feature recognition techniques.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"179 ","pages":"Article 103813"},"PeriodicalIF":3.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657977","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

SITF: A Self-Supervised Iterative Training Framework for Point Cloud Denoising SITF：用于点云去噪的自监督迭代训练框架

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-10-18 DOI: 10.1016/j.cad.2024.103812

Zhiyong Su , Changchang Wang , Kun Jiang , Kai Jiang , Weiqing Li

{"title":"SITF: A Self-Supervised Iterative Training Framework for Point Cloud Denoising","authors":"Zhiyong Su , Changchang Wang , Kun Jiang , Kai Jiang , Weiqing Li","doi":"10.1016/j.cad.2024.103812","DOIUrl":"10.1016/j.cad.2024.103812","url":null,"abstract":"<div><div>Despite existing supervised point cloud denoising methods having made great progress, they require paired ideal noisy-clean datasets for training which is expensive and impractical in real-world applications. Moreover, they may perform the denoising process multiple times with fixed network parameters for better denoising results at test time. To address above issues, this paper proposes a self-supervised iterative training framework (SITF) for point cloud denoising, which only requires single noisy point clouds and a noise model. Given an off-the-shelf denoising network and original noisy point clouds, firstly, an intermediate noisier-noisy dataset is created by adding additional noises from the known noise model to noisy point clouds (i.e. learning targets). Secondly, after training on the noisier-noisy dataset, the denoising network is employed to denoise the original noisy point clouds to obtain the learning targets for the next iteration. The above two steps are iteratively and alternatively performed to get a better and better trained denoising network. Furthermore, to get better learning targets for the next round, this paper also proposes a novel iterative denoising network (IDN) architecture of stacked source attention denoising modules. The IDN explicitly models the iterative denoising process internally within a single network via reforming the given denoising network. Experimental results show that existing supervised networks trained through the SITF can achieve competitive denoising results and even outperform supervised networks under high noise conditions. The source code can be found at: <span><span>https://github.com/VCG-NJUST/SITF</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"179 ","pages":"Article 103812"},"PeriodicalIF":3.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528272","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

Two-Level High-Resolution Structural Topology Optimization with Equilibrated Cells 利用平衡单元进行两级高分辨率结构拓扑优化

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-10-17 DOI: 10.1016/j.cad.2024.103811

Rafael Merli , Antolín Martínez-Martínez , Juan José Ródenas , Marc Bosch-Galera , Enrique Nadal

{"title":"Two-Level High-Resolution Structural Topology Optimization with Equilibrated Cells","authors":"Rafael Merli , Antolín Martínez-Martínez , Juan José Ródenas , Marc Bosch-Galera , Enrique Nadal","doi":"10.1016/j.cad.2024.103811","DOIUrl":"10.1016/j.cad.2024.103811","url":null,"abstract":"<div><div>In today’s industry, the rapid evolution in the design and development of optimized mechanical components to meet customer requirements represents a significant challenge for companies. These companies seek efficient solutions to enhance their products in terms of stiffness and strength. One powerful approach is Topology Optimization, which aims to determine the optimal material distribution within a predefined domain to maximize the overall component’s stiffness. Achieving high-resolution solutions is also crucial for accurately defining the final material distribution. While standard Topology Optimization tools can propose optimal solutions for entire components, they struggle with small-scale details (such as trabecular structures) due to prohibitive computational costs. To address this issue, our proposed approach introduces a two-level topology optimization methodology considering density-based techniques. The proposed methodology includes three steps: The first one subdivides the whole component in cells and generates a coarse optimized low-definition material distribution, assigning a different density to each cell. Since the output stresses from the coarse problem are not equilibrated into each cell, they must not be directly used in the fine level. Thus, the second step uses the equilibrating traction recovery approach to convert the cell nodal forces into equilibrated lateral tractions over the cell boundary. Finally, taking as input data the densities from the coarse optimization and imposing these lateral tractions as Neumann boundary conditions, each cell is optimized at fine level. The main goal of this work is to efficiently solve high-resolution topology optimization problems using a two-level mechanically-continuous method, which would be unaffordable with standard computing facilities and the current techniques.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"179 ","pages":"Article 103811"},"PeriodicalIF":3.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528347","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

SplineGen: Approximating unorganized points through generative AI SplineGen：通过生成式人工智能逼近无组织点

IF 3 3区计算机科学

Computer-Aided Design Pub Date : 2024-10-10 DOI: 10.1016/j.cad.2024.103809

Qiang Zou, Lizhen Zhu, Jiayu Wu, Zhijie Yang

{"title":"SplineGen: Approximating unorganized points through generative AI","authors":"Qiang Zou, Lizhen Zhu, Jiayu Wu, Zhijie Yang","doi":"10.1016/j.cad.2024.103809","DOIUrl":"10.1016/j.cad.2024.103809","url":null,"abstract":"<div><div>This paper presents a learning-based method to solve the traditional parameterization and knot placement problems in B-spline approximation. Different from conventional heuristic methods or recent AI-based methods, the proposed method does not assume ordered or fixed-size data points as input. There is also no need for manually setting the number of knots. Parameters and knots are generated in an associative way to attain better parameter-knot alignment, and therefore a higher approximation accuracy. These features are attained by using a new generative model SplineGen, which casts the parameterization and knot placement problems as a sequence-to-sequence translation problem. It first adopts a shared autoencoder model to learn a 512-D embedding for each input point, which has the local neighborhood information implicitly captured. Then these embeddings are autoregressively decoded into parameters and knots by two associative decoders, a generative process automatically determining the number of knots, their placement, parameter values, and their ordering. The two decoders are made to work in a coordinated manner by a new network module called internal cross-attention. Once trained, SplineGen demonstrates a notable improvement over existing methods, with one to two orders of magnitude increase in approximation accuracy on test data.</div></div>","PeriodicalId":50632,"journal":{"name":"Computer-Aided Design","volume":"178 ","pages":"Article 103809"},"PeriodicalIF":3.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433629","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