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期刊论文 36

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B样条函数 1

C-Bézier曲面;降阶;边界约束 1

三维构造 1

三维点云;孔洞修补;立体匹配;B样条 1

临界应力 1

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交互式图像分割;多元自适应回归样条;集成学习;薄板样条回归;半监督学习;支持向量回归 1

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吸附 1

地质曲面 1

多源地质数据 1

大幅面 1

子模型 1

废水处理 1

弯曲结构表面;柔性加速度计;微机电系统(MEMS)技术;无线非接触式测量 1

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Interpolation of a spline developable surface between a curve and two rulings

Alicia CANTÓN,Leonardo FERNÁNDEZ-JAMBRINA

《信息与电子工程前沿(英文)》 2015年 第16卷 第3期   页码 173-190 doi: 10.1631/FITEE.14a0210

摘要: In this paper we address the problem of interpolating a spline developable patch bounded by a given spline curve and the first and the last rulings of the developable surface. To complete the boundary of the patch, a second spline curve is to be given. Up to now this interpolation problem could be solved, but without the possibility of choosing both endpoints for the rulings. We circumvent such difficulty by resorting to degree elevation of the developable surface. This is useful for solving not only this problem, but also other problems dealing with triangular developable patches.

关键词: Developable surfaces     Spline surfaces     Blossoms    

Multiresolution and multimaterial topology optimization of fail-safe structures under B-spline spaces

《机械工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11465-023-0768-9

摘要: This study proposes a B-spline-based multiresolution and multimaterial topology optimization (TO) design method for fail-safe structures (FSSs), aiming to achieve efficient and lightweight structural design while ensuring safety and facilitating the postprocessing of topological structures. The approach involves constructing a multimaterial interpolation model based on an ordered solid isotropic material with penalization (ordered-SIMP) that incorporates fail-safe considerations. To reduce the computational burden of finite element analysis, we adopt a much coarser analysis mesh and finer density mesh to discretize the design domain, in which the density field is described by the B-spline function. The B-spline can efficiently and accurately convert optimized FSSs into computer-aided design models. The 2D and 3D numerical examples demonstrate the significantly enhanced computational efficiency of the proposed method compared with the traditional SIMP approach, and the multimaterial TO provides a superior structural design scheme for FSSs. Furthermore, the postprocessing procedures are significantly streamlined.

关键词: multiresolution     multimaterial     topology optimization     fail-safe structure     B-spline    

指数多项式均匀样条模型

赵颜利,平萍,刘凤玉

《中国工程科学》 2008年 第10卷 第7期   页码 147-152

摘要:

给出了k( k ≥ 3) 阶指数多项式的均匀样条模型。该类模型具有很多与B 样条模型相同的性质,并 且增加了一个可调节的形状参数。由该模型构造的曲线,通过改变形状参数的取值,可以调整曲线接近其控 制多边形的程度。应用于CAD/CAM领域,可作为几何造型的一种新的有效模型。

关键词: 指数多项式样条函数     B样条函数     形状参数    

Crack fault quantitative diagnosis based on finite element of B-spline wavelet on the interval

XIANG Jia-wei, CHEN Xue-feng, HE Zheng-jia, HE Yu-min

《机械工程前沿(英文)》 2006年 第1卷 第2期   页码 177-182 doi: 10.1007/s11465-006-0001-7

摘要: The model-based forward and inverse problems in the diagnosis of structural crack faults were studied. The forward problem is to solve the natural frequencies through a cracked structural model and the inverse problem is to quantitatively determine the crack parameters using the experimental testing frequencies. Then, the one-dimensional crack element of B-spline wavelet on the interval (BSWI) was built to solve the forward problem. Contour plots of normalized crack location versus normalized crack size were plotted by using the first three natural frequencies as the inputs. The intersection of the three curves predicted the normalized crack location and size. The experimental study verified the validity of the wavelet-based crack element in solving crack singular problems to overcome the disadvantages of the traditional finite element method (FEM), such as low efficiency, insufficient accuracy, slow convergence to correct solutions, etc. At the same time, it had adequate identification precision. The new method can be applied to prognosis and quantitative diagnosis of incipient crack.

关键词: one-dimensional     B-spline     incipient     prognosis     identification precision    

Geosynthetics used to stabilize vegetated surfaces for environmental sustainability in civil engineering

Jie HAN,Jun GUO

《结构与土木工程前沿(英文)》 2017年 第11卷 第1期   页码 56-65 doi: 10.1007/s11709-016-0380-8

摘要: Geosynthetics, factory-manufactured polymer materials, have been successfully used to solve many geotechnical problems in civil engineering. Two common applications are earth stabilization and erosion control. Geosynthetics used for earth stabilization include but are not limited to stabilized slopes, walls, embankments, and roads. Geosynthetics used for erosion control are mostly related to slopes, river channels and banks, and pond spillways. To enhance environmental sustainability, vegetation has been increasingly planted on the facing or surfaces of these earth structures. Under such a condition, geosynthetics mainly function as surficial soil stabilization while vegetation provides green appearance and erosion protection of earth surfaces. Recently, geosynthetic or geosynthetic-like material has been used to form green walls outside or inside buildings to enhance sustainability. Geosynthetics and vegetation are often integrated to provide combined benefits. The interaction between geosynthetics and vegetation is important for the sustainability of the earth and building wall surfaces. This paper provides a review of the current practice and research in the geosynthetic stabilization of vegetated earth and building surfaces for environmental sustainability in civil engineering with the emphases on geosynthetic used for erosion protection, geosynthetic-stabilized slopes, geosynthetic-stabilized unpaved shoulders and parking lots, and geosynthetic-stabilized vegetated building surfaces.

关键词: erosion     geosynthetic     stabilization     sustainability     vegetation    

Contact of surfaces and contact characteristics of offset surfaces

CAO Lixin, GONG Hu, LIU Jian

《机械工程前沿(英文)》 2008年 第3卷 第3期   页码 318-324 doi: 10.1007/s11465-008-0067-5

摘要: Based on differential geometry, the contact problems of two surfaces are discussed in this paper. The relationship between the contact status of two surfaces and that of offset surfaces are also analyzed. For a 5-axis NC machining, some research such as optimization of cutter location and calculation of the geometrical cusp height are important. The research results indicate that the relative normal curvature is an important geometrical invariant for describing the contact state of two surfaces. For point contact two surfaces, the calculation equation for the second order remained error is given. For line contact two surfaces, the condition of the second order line contact is that the principal directions and curvatures of the two surfaces are the same along the contact curve. If two surfaces keep the second order line contact, their two offset surfaces will also keep the second order line contact, and their third order remained errors are also uniform with that of the two offset surfaces.

关键词: relative     important geometrical     relationship     geometrical invariant     calculation    

Optimal localization of complex surfaces in CAD-based inspection

XU Jinting, LIU Weijun, SUN Yuwen

《机械工程前沿(英文)》 2008年 第3卷 第4期   页码 426-433 doi: 10.1007/s11465-008-0068-4

摘要: Complex surface inspection requires the optimal localization of the measured surface related to the design surface so that the two surfaces can be compared in a common coordinate frame. This paper presents a new technique for solving the localization problem. The basic approach consists of two steps: 1) rough localization of the measured points to the design surface based on curvature features, which can produce a good initial estimate for the optimal localization; 2) fine localization based on the least-square principle so that the deviation between the measured surface and the design surface is minimized. To efficiently compute the closest points on the design surface of the measured points, a novel method is proposed. Since this approach does not involve an iterative process of solving non-linear equations for the closest points, it is more convenient and robust. The typical complex surface is used to test the developed algorithm. Analysis and comparison of experimental results demonstrate the validity and applicability of the algorithm.

关键词: deviation     comparison     non-linear     localization     inspection    

Strategies on designing multifunctional surfaces to prevent biofilm formation? ?

Yang Lu,Zhanguo Yue,Wei Wang,Zhiqiang Cao

《化学科学与工程前沿(英文)》 2015年 第9卷 第3期   页码 324-335 doi: 10.1007/s11705-015-1529-z

摘要: Bacteria adhesion and biofilm formation have raised severe problems on public health, food industry and many other areas. A variety of reagents and surface coatings have been developed to kill bacteria and/or limit their interaction with surfaces. It has also attracted many efforts to integrate different bactericidal elements together and maximize antibacterial efficiency. Herein, we review mechanisms for both passive and active approaches to resist and kill bacteria respectively, and discuss integrated strategies based on these two approaches. We also offer perspective on future research direction.

关键词: antimicrobial     surface     multifunctional    

Morphologies of diblock copolymer confined in a slit with patterned surfaces studied by dissipative particle

FENG Jian, HUANG Yongmin, LIU Honglai, HU Ying

《化学科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 132-139 doi: 10.1007/s11705-007-0025-5

摘要: Diblock copolymers with ordered mesophase structures have been used as templates for nano-fabrication. Unfortunately, the ordered structure only exists at micrometer-scale areas, which precludes its use in many advanced applications. To overcome this disadvantage, the diblock copolymer confined in a restricted system with a patterned surface is proved to be an effective means to prohibit the formation of defects and obtain perfect ordered domains. In this work, the morphologies of a thin film of diblock copolymer confined between patterned and neutral surfaces were studied by dissipative particle dynamics. It is shown that the morphology of the symmetric diblock copolymer is affected by the ratio of the pattern period on the surface to the lamellar period of the symmetric diblock copolymer and by the repulsion parameters between blocks and wall particles. To eliminate the defects in the lamellar phase, the pattern period on the surface must match the lamellar period. The difference in the interface energy of different compartments of the pattern should increase with increasing film thickness. The pattern period on the surface has a scaling relationship with the chain length, which is the same as that between the lamellar period and the chain length. The lamellar period is also affected by the polydispersity of the symmetric diblock copolymer. The total period is the average of the period of each component multiplied by the weight of its volume ratio. The morphologies of asymmetric diblock copolymers are also affected by the pattern on the surface, especially when the matching period of the asymmetric diblock copolymer is equal to the pattern period, which is approximately equal to the lamellar period of a symmetric diblock copolymer with the same chain length.

关键词: weight     nano-fabrication     morphology     matching     dissipative particle    

A hypothesis for crack free interior surfaces of Longyou caverns caved in argillaceous siltstone 2000

Zhong Qi YUE, Shaopeng FAN, Zhifa YANG, Lihui LI, Luqing ZHANG, Zhongjian ZHANG,

《结构与土木工程前沿(英文)》 2010年 第4卷 第2期   页码 165-177 doi: 10.1007/s11709-010-0018-1

摘要: Five complete caverns were discovered in Longyou in 1992. They were manually caved in argillaceous siltstone at shallow depths more than 2000 years ago. When they were un-watered, their integrity was maintained completely, and their interior rock surfaces were free of old cracks. Since then, however, the rock’s interior faces have initiated and propagated more and more cracks. This paper attempts to address the question of why the rock interior faces were free of old cracks once they were unearthed. To address this question, this paper proposes a hypothesis that the argillaceous siltstone has the ability of self-healing its cracks over a short period of time under weak acid water environment. Data and evidence are presented herewith to prove the hypothesis. They include observations and measurements in the field and test results in the laboratory. Specifically, a three-point bending test is used to form a tensile crack in a rectangular rock specimen and a dead load test for the specimen immersed in initially weak acid water is used for self-healing its crack. The results have shown that the argillaceous siltstone is in a state of weak alkalinity and the rain water at the site is in a state of weak acidity. Therefore, when it is immersed in weak acid water for some time, the argillaceous siltstone would be able to make chemical reactions to generate new minerals such as calcite. The new minerals would be able to infill the cracks and then heal the crack within a few years. Once the crack is self-healed, the rock can regain its strength and integrity. Consequently, the rock interior surfaces could be free of old cracks when the water was pumped out of the caverns.

关键词: rock cavern     grotto     Longyou     argillaceous siltstone     crack     water     environment     self-healing    

Optimal design analysis of a tubular heat exchanger network with extended surfaces using multi-objective

Hassan HAJABDOLLAHI, Mohammad SHAFIEY DEHAJ, Babak MASOUMPOUR, Mohammad ATAEIZADEH

《能源前沿(英文)》 2022年 第16卷 第5期   页码 862-875 doi: 10.1007/s11708-022-0839-3

摘要: The present work aims to investigate the influence of extended surfaces (fins) on the multi-objective optimization of a tubular heat exchanger network (THEN). An increase in the heat transfer area using various extended surfaces (fins) to enhance the performance of the heat exchanger was used while considering the effectiveness and total heat transfer area as two objective functions. In addition to the simulation of simple fins, a new set of fins, called constructal fins, was designed based on the constructal theory. Tubular heat exchanger network design parameters were chosen as optimization variables, and optimization results were achieved in such a way as to enhance the effectiveness and decrease the total heat transfer area. The results show the importance of constructal fins in improving the objective functions of heat exchangers. For instance, the simple fins case enhances the effectiveness by up to 5.3% compared to that without fins (usual heat exchanger) while using constructal fins, in addition to the 7% increment of effectiveness, reduces the total heat transfer area by 9.47%. In order to optimize the heat exchanger, the heat transfer rate and cold fluid temperature must increase, and at the same time, the hot exiting fluid temperature should decrease at the same constant total heat transfer area, which is higher in the constructal fins case. Finally, optimized design variables were studied for different cases, and the effects of various fins were reported.

关键词: constructal theory     extended surface     effectiveness     total heat transfer area     multi-objective optimization    

Leidenfrost drops on micro/nanostructured surfaces

Vishal TALARI, Prakhar BEHAR, Yi LU, Evan HARYADI, Dong LIU

《能源前沿(英文)》 2018年 第12卷 第1期   页码 22-42 doi: 10.1007/s11708-018-0541-7

摘要: In the Leidenfrost state, the liquid drop is levitated above a hot solid surface by a vapor layer generated via evaporation from the drop. The vapor layer thermally insulates the drop from the heating surface, causing deteriorated heat transfer in a myriad of important engineering applications. Thus, it is highly desirable to suppress the Leidenfrost effect and elevate the Leidenfrost temperature. This paper presents a comprehensive review of recent literature concerning the Leidenfrost drops on micro/nanostructured surfaces with an emphasis on the enhancement of the Leidenfrost temperature. The basic physical processes of the Leidenfrost effect and the key characteristics of the Leidenfrost drops were first introduced. Then, the major findings of the influence of various micro/nanoscale surface structures on the Leidenfrost temperature were presented in detail, and the underlying enhancement mechanism for each specific surface topology was also discussed. It was concluded that multiscale hierarchical surfaces hold the best promise to significantly boost the Leidenfrost temperature by combining the advantages of both micro- and nanoscale structures.

关键词: Leidenfrost drop     Leidenfrost temperature     heat transfer enhancement     micro/nanostructured surfaces    

带约束条件的C-Bézier曲面最优降多阶逼近 Article

Lian ZHOU, Xin-hui LIN, Hong-yan ZHAO, Jun CHEN

《信息与电子工程前沿(英文)》 2017年 第18卷 第12期   页码 2009-2016 doi: 10.1631/FITEE.1700458

摘要: 本文提出了一种在L2范数下C-Bézier曲面带约束条件的降多阶逼近最优方法。利用C-Bézier基函数的转换矩阵,得到了降阶曲面控制顶点的显式矩阵表示。结合指定的边界约束条件,该法利用于对分片连续曲面或细分子曲面同时降多阶逼近,所得到的系列降阶曲面整体上保持G1连续。数值实验表明该方法的优质高效。

关键词: C-Bézier曲面;降阶;边界约束    

基于形参均匀B样条盈亏修正的图像边缘检测

赵颜利,王湛,郭成昊,刘凤玉

《中国工程科学》 2007年 第9卷 第7期   页码 65-70

摘要:

利用形参均匀B样条平滑公式,建立了一种盈亏修正的图像边缘检测新方法。首先对图像的原型值点进行盈亏修正,进一步减少原始图像和平滑图像之间的残余误差;然后利用形参均匀B样条修匀公式对修正后的图像拟合光滑曲面;最后求拟合后的光滑曲面的一阶导数极值点或二阶导数的零交叉点作为边缘特征点。试验表明,该方法稳定可靠,精度较高,能够很好地去除伪边缘;同时该方法简洁,便于实时处理。

关键词: 形状参数均匀B样条     边缘检测     计算机视觉     盈亏修正    

基于Bézier曲线的柔性曲面装配变动分析 None

Zhen-yu LIU, Shi-en ZHOU, Jin CHENG, Chan QIU, Jian-rong TAN

《信息与电子工程前沿(英文)》 2018年 第19卷 第6期   页码 796-808 doi: 10.1631/FITEE.1601619

摘要: 在装配过程中,柔性零件表面特征会发生形状变化,相比刚性体,其变动分析复杂许多。现有柔性装配变动分析方法大多未考虑零件表面邻近点的相互关系,或者将零件表面上所有特征点的概率分布情况视为统一。本文将柔性曲面零件装配简化为边侧线匹配问题,提出基于Bézier曲线来表征曲面零件边侧线的方法,解决了柔性零件装配中考虑表面连续性的曲面零件装配变动分析问题。该方法利用控制点变动来获取零件边侧线上特征点的偏差,并将它们作为输入参数进行有限元分析,从而计算出最终产品变形量。通过天线表面装配的两个实例,对所提方法进行了验证。

关键词: 装配变动分析;特征点;边侧线;柔性曲面;Bézier曲线    

标题 作者 时间 类型 操作

Interpolation of a spline developable surface between a curve and two rulings

Alicia CANTÓN,Leonardo FERNÁNDEZ-JAMBRINA

期刊论文

Multiresolution and multimaterial topology optimization of fail-safe structures under B-spline spaces

期刊论文

指数多项式均匀样条模型

赵颜利,平萍,刘凤玉

期刊论文

Crack fault quantitative diagnosis based on finite element of B-spline wavelet on the interval

XIANG Jia-wei, CHEN Xue-feng, HE Zheng-jia, HE Yu-min

期刊论文

Geosynthetics used to stabilize vegetated surfaces for environmental sustainability in civil engineering

Jie HAN,Jun GUO

期刊论文

Contact of surfaces and contact characteristics of offset surfaces

CAO Lixin, GONG Hu, LIU Jian

期刊论文

Optimal localization of complex surfaces in CAD-based inspection

XU Jinting, LIU Weijun, SUN Yuwen

期刊论文

Strategies on designing multifunctional surfaces to prevent biofilm formation? ?

Yang Lu,Zhanguo Yue,Wei Wang,Zhiqiang Cao

期刊论文

Morphologies of diblock copolymer confined in a slit with patterned surfaces studied by dissipative particle

FENG Jian, HUANG Yongmin, LIU Honglai, HU Ying

期刊论文

A hypothesis for crack free interior surfaces of Longyou caverns caved in argillaceous siltstone 2000

Zhong Qi YUE, Shaopeng FAN, Zhifa YANG, Lihui LI, Luqing ZHANG, Zhongjian ZHANG,

期刊论文

Optimal design analysis of a tubular heat exchanger network with extended surfaces using multi-objective

Hassan HAJABDOLLAHI, Mohammad SHAFIEY DEHAJ, Babak MASOUMPOUR, Mohammad ATAEIZADEH

期刊论文

Leidenfrost drops on micro/nanostructured surfaces

Vishal TALARI, Prakhar BEHAR, Yi LU, Evan HARYADI, Dong LIU

期刊论文

带约束条件的C-Bézier曲面最优降多阶逼近

Lian ZHOU, Xin-hui LIN, Hong-yan ZHAO, Jun CHEN

期刊论文

基于形参均匀B样条盈亏修正的图像边缘检测

赵颜利,王湛,郭成昊,刘凤玉

期刊论文

基于Bézier曲线的柔性曲面装配变动分析

Zhen-yu LIU, Shi-en ZHOU, Jin CHENG, Chan QIU, Jian-rong TAN

期刊论文