Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 197

会议视频 2

年份

2023 25

2022 19

2021 17

2020 9

2019 14

2018 10

2017 11

2016 11

2015 5

2014 4

2013 4

2012 4

2011 6

2010 8

2009 8

2008 11

2007 9

2006 2

2005 6

2004 6

展开︾

关键词

三峡工程 2

仿真优化 2

自主开发 2

&ldquo 1

12相整流 1

3D打印 1

ANFIS 1

ARM 1

CAE 1

CAN总线 1

CPR1000 1

Cu(In 1

Ga)Se₂光伏组件 1

IC产业 1

IEEE80216 1

Mesh 1

SAC 1

UniDrop 1

Walsh循环谱 1

展开︾

检索范围：

排序：展示方式：

Self-motions of 3-RPS manipulators

Josef SCHADLBAUER, Manfred L. HUSTY, Stéphane CARO, Philippe WENGERY

《机械工程前沿（英文）》 2013年第8卷第1期页码 62-69 doi: 10.1007/s11465-013-0366-3

摘要：

Recently a complete kinematic description of the 3-RPS parallel manipulator was obtained using algebraic constraint equations. It turned out that the workspace splits into two components describing two kinematically different operation modes. In this paper the algebraic description is used to give a complete analysis of all possible self-motions of this manipulator in both operation modes. Furthermore it is shown that a transition from one operation mode into the other in a self-motion is possible.

关键词： 3-RPS-manipulator singularity self-motion

HTML PDF 收藏

Singularity loci of an orthogonal spherical two-degree-of-freedom parallel mechanism

Jialun YANG, Feng GAO,

《机械工程前沿（英文）》 2009年第4卷第4期页码 379-385 doi: 10.1007/s11465-009-0075-0

摘要： Singularity analysis plays an important role in the design of robots, especially for parallel robots. In this paper, the direct and inverse kinematics of an orthogonal spherical two-degree-of-freedom parallel mechanism is proposed based on the modified Euler angles. All the singular poses of the mechanism are achieved through the direct kinematic analysis. Self-motions, which are different from the general spherical 5 parallel mechanisms, are also discussed. Singularity loci in the joint space and Cartesian space are plotted according to the Jacobin of the mechanism. Result shows that the singularity loci at the joint space are two circles and one line, whereas at the Cartesian space are a circle.

关键词： 2-DOF orthogonal spherical parallel mechanism singularity loci self-motions

HTML PDF 收藏

Cusp points and assembly changing motions in the PRR-PR-PRR planar parallel manipulator

《机械工程前沿（英文）》 2023年第18卷第2期 doi: 10.1007/s11465-022-0743-x

摘要： Most parallel manipulators have multiple solutions to the direct kinematic problem. The ability to perform assembly changing motions has received the attention of a few researchers. Cusp points play an important role in the kinematic behavior. This study investigates the cusp points and assembly changing motions in a two degrees of freedom planar parallel manipulator. The direct kinematic problem of the manipulator yields a quartic polynomial equation. Each root in the equation determines the assembly configuration, and four solutions are obtained for a given set of actuated joint coordinates. By regarding the discriminant of the repeated roots of the quartic equation as an implicit function of two actuated joint coordinates, the direct kinematic singularity loci in the joint space are determined by the implicit function. Cusp points are then obtained by the intersection of a quadratic curve and a cubic curve. Two assembly changing motions by encircling different cusp points are highlighted, for each pair of solutions with the same sign of the determinants of the direct Jacobian matrices.

关键词： planar parallel manipulator assembly changing motions cusp points quartic polynomial discriminant of repeated roots

HTML PDF 收藏

Exploring self-organization and self-adaption for smart manufacturing complex networks

《工程管理前沿（英文）》 2023年第10卷第2期页码 206-222 doi: 10.1007/s42524-022-0225-1

摘要： Trends toward the globalization of the manufacturing industry and the increasing demands for small-batch, short-cycle, and highly customized products result in complexities and fluctuations in both external and internal manufacturing environments, which poses great challenges to manufacturing enterprises. Fortunately, recent advances in the Industrial Internet of Things (IIoT) and the widespread use of embedded processors and sensors in factories enable collecting real-time manufacturing status data and building cyber–physical systems for smart, flexible, and resilient manufacturing systems. In this context, this paper investigates the mechanisms and methodology of self-organization and self-adaption to tackle exceptions and disturbances in discrete manufacturing processes. Specifically, a general model of smart manufacturing complex networks is constructed using scale-free networks to interconnect heterogeneous manufacturing resources represented by network vertices at multiple levels. Moreover, the capabilities of physical manufacturing resources are encapsulated into virtual manufacturing services using cloud technology, which can be added to or removed from the networks in a plug-and-play manner. Materials, information, and financial assets are passed through interactive links across the networks. Subsequently, analytical target cascading is used to formulate the processes of self-organizing optimal configuration and self-adaptive collaborative control for multilevel key manufacturing resources while particle swarm optimization is used to solve local problems on network vertices. Consequently, an industrial case based on a Chinese engine factory demonstrates the feasibility and efficiency of the proposed model and method in handling typical exceptions. The simulation results show that the proposed mechanism and method outperform the event-triggered rescheduling method, reducing manufacturing cost, manufacturing time, waiting time, and energy consumption, with reasonable computational time. This work potentially enables managers and practitioners to implement active perception, active response, self-organization, and self-adaption solutions in discrete manufacturing enterprises.

关键词： cyber–physical systems Industrial Internet of Things smart manufacturing complex networks self-organization and self-adaption analytical target cascading collaborative optimization

HTML PDF 收藏

过程强化装置中双偏心转子的运动分析

朱瑞林,朱国林

《中国工程科学》 2012年第14卷第10期页码 90-96

摘要：

当偏心转子绕定轴旋转时，实际上只有其几何圆心作简谐振动（正/余弦运动），某些情况下由转子驱动的构件（如活塞）并不能作同样的简谐振动，因此在一些过程设备上应用双偏心转子时，会引起一些相关问题，如压力变化问题。为此，在分析一种过程强化装置中所采用的双偏心转子的运动规律的基础上，发现了由于偏心转子所驱动的两活塞的运动不完全对称，可能引起设备内介质压力变化的原因，并提出了相应的解决措施。

关键词：转子活塞简谐振动

HTML PDF 收藏

Parasitic rotation evaluation and avoidance of 3-UPU parallel mechanism

Haibo QU, Yuefa FANG, Sheng GUO

《机械工程前沿（英文）》 2012年第7卷第2期页码 210-218 doi: 10.1007/s11465-012-0317-4

摘要：

Based on the prototype of 3-UPU (universal-prismatic-universal joint) parallel mechanism proposed by Tsai [ ], the parasitic rotation evaluation is performed and calculated the bound of instability of SNU Seoul National University 3-UPU parallel mechanism. Through analysis of the terminal constraint system of the 3-UPU parallel mechanism, the equation about the parasitic rotation and limited clearance is presented. Then the norm of possible parasitic rotation is employed to evaluate the mechanism stability with limited clearance. The higher this number the worst is the pose, the lower it is the best it is. And the contour atlas of parasitic rotation is obtained, which can be used for further analysis and design. With the practice experiment result of SUN 3-UPU parallel mechanism, we find it’s bound of instability, which indicates there will appear the parasitic rotation when the number exceeds the bound. Finally, the method for avoidance of possible parasitic motions is presented by adding redundantly actuated limbs.

关键词： parallel mechanism 3-UPU (universal-prismatic-universal joint) parasitic motions limited clearance redundantly actuated limbs

HTML PDF 收藏

Emerging trends in self-healable nanomaterials for triboelectric nanogenerators: A comprehensive review

《能源前沿（英文）》页码 727-750 doi: 10.1007/s11708-023-0896-2

摘要： A thorough analysis of triboelectric nanogenerators (TENGs) that make use of self-healable nanomaterials is presented in this review. These TENGs have shown promise as independent energy sources that do not require an external power source to function. TENGs are developing into a viable choice for powering numerous applications as low-power electronics technology advances. Despite having less power than conventional energy sources, TENGs do not directly compete with these. TENGs, on the other hand, provide unique opportunities for future self-powered systems and might encourage advancements in energy and sensor technologies. Examining the many approaches used to improve nanogenerators by employing materials with shape memory and self-healable characteristics is the main goal of this review. The findings of this comprehensive review provide valuable information on the advancements and possibilities of TENGs, which opens the way for further research and advancement in this field. The discussion of life cycle evaluations of TENGs provides details on how well they perform in terms of the environment and identifies potential improvement areas. Additionally, the cost-effectiveness, social acceptability, and regulatory implications of self-healing TENGs are examined, as well as their economic and societal ramifications.

关键词： triboelectric nanogenerator (TENG) self-healable nanomaterials self-powered devices energy

HTML PDF 收藏

Modular structure of a self-reconfigurable robot

FEI Yanqiong, DONG Qinglei, ZHAO Xifang

《机械工程前沿（英文）》 2007年第2卷第1期页码 116-119 doi: 10.1007/s11465-007-0020-z

摘要： This paper proposes a novel, hermaphroditic, and lattice self-reconfigurable modular robot. Each module is composed of a center body a cubic part and six sides that can rotate independently. There are two holes and two extensible pegs on each side. The rotary motion of each side and the extensible motion of the pegs are generated by a motor connected to a reducer, using a cone-shaped gear, belt, clutch, etc. The structure of the module is compact, and has space to extend further.

关键词： compact self-reconfigurable modular hermaphroditic cone-shaped clutch

HTML PDF 收藏

Signal separation technology for diphase opposition giant magnetostrictive self-sensing actuator

Xinhua WANG, Shuwen SUN, Jian ZHEN, Qianyi YA, Deguo WANG,

《机械工程前沿（英文）》 2010年第5卷第2期页码 176-183 doi: 10.1007/s11465-010-0001-5

摘要： The structure and principle of a new type of a diphase opposition giant magnetostrictive self-sensing actuator is introduced. A bridge analysis model based on variable inductance is established. Dynamic balance separation technology for the giant magnetostrictive self-sensing actuator comes true by the least means square (LMS) self-adapting algorithm. The scheme design of one important part of the circuit with the real-time separation circuit of the dynamic balance signal based on a digital signal processor is obtained. The part of the signal separated circuit is designed, which includes logarithmic-antilog practical multiplication circuit, amplifying circuit, filter circuits, and amplifier circuit. Based on the embedded system simulation software—PROTUES, the simulation effect of the circuit that separates the sensing signal from the mixed signals is obvious, which indicates that the circuit can rapidly and stably work. Moreover, the structure is simple, reliable, and meets the practical requirement.

关键词： giant magnetostrictive material (GMM) self-sensing actuator least means square (LMS) self-adapting algorithm design of self-adaptive circuit

HTML PDF 收藏

A comprehensive analysis of a 3-P (Pa) S spatial parallel manipulator

Yuzhe LIU,Liping WANG,Jun WU,Jinsong WANG

《机械工程前沿（英文）》 2015年第10卷第1期页码 7-19 doi: 10.1007/s11465-015-0324-3

摘要：

In this paper, a novel 3-degree of freedom (3-DOF) spatial parallel kinematic machine (PKM) is analyzed. The manipulator owns three main motions (two rotations and one translation) and three concomitant motions (one rotation and two translations). At first, the structure of this spatial PKM is simplified according to the characteristic of each limb. Secondly, the kinematics model of this spatial PKM is set up. In addition, the relationship between the main motions and concomitant motions is studied. The workspaces respectively based on the outputs and inputs are derived and analyzed. Furthermore, the velocity model is put forward. Two indexes based on the velocity model are employed to investigate the performance of this spatial PKM. At last, the output error model can be obtained and simulated. The comprehensive kinematics analysis in this paper is greatly useful for the future applications of this spatial PKM.

关键词： parallel mechanism concomitant motions kinematics workspaces error model

HTML PDF 收藏

Behaviour of self-centring shear walls——A state of the art review

《结构与土木工程前沿（英文）》 2023年第17卷第1期页码 53-77 doi: 10.1007/s11709-022-0850-0

摘要： The application of unbonded post-tensioning (PT) in structural walls has led to the development of advanced self-centring (rocking) shear wall systems that has significant advantages, including accelerated construction due to the incorporation of prefabricated elements and segmental construction for different materials (e.g., concrete, masonry, and timber), reduced residual drifts, and little damage upon extreme seismic and wind loads. Concrete, masonry, and timber are often used for the construction of unbonded PT structural wall systems. Despite extensive research since the 1980s, there are no well-established design guidelines available on the shear wall configuration with the required energy dissipation system, joint’s locations and acceptance criteria for shear sliding, confinement, seismic performance factors, PT loss, PT force range and residual drifts of shear walls subjected to lateral loads. In this research a comprehensive state-of-the-art literature review was performed on self-centring shear wall system. An extensive study was carried out to collect a database of 100 concrete, masonry, and self-centring shear wall tests from the literature. The established database was then used to review shear walls’ configurations, material, and components to benchmark requirements applicable for design purposes. The behaviour of concrete, masonry and timber shear walls were compared and critically analysed. The general behaviour, force-displacement performance of the walls, ductility, and seismic response factors, were critically reviewed and analysed for different self-centring wall systems to understand the effect of different parameters including configurations of the walls, material used for construction of the wall (concrete, masonry, timber) and axial stress ratio. The outcome of this research can be used to better understand the behaviour of self-centring wall system in order to develop design guidelines for such walls.

关键词： self-centring shear walls rocking walls energy dissipation seismic performance factors PT loss residual drift

HTML PDF 收藏

Recycled glass replacement as fine aggregate in self-compacting concrete

Yasser SHARIFI, Mahmoud HOUSHIAR, Behnam AGHEBATI

《结构与土木工程前沿（英文）》 2013年第7卷第4期页码 419-428 doi: 10.1007/s11709-013-0224-8

摘要： With increasing environmental pressure to reduce solid waste and to recycle as much as possible, the concrete industry has adopted a number of methods to achieve this goal by replacement of waste glass with concrete composition materials. Due to differences in mixture design, placement and consolidation techniques, the strength and durability of Self Compacting Concrete (SCC) may be different than those of conventional concrete. Therefore, replacement of waste glass with fine aggregate in SCC should deeply be investigated compared to conventional concretes. The aim of the present study is to investigate the effect of glass replacement with fine aggregate on the SCC properties. In present study, fine aggregate has been replaced with waste glass in six different weight ratios ranging from 0% to 50%. Fresh results indicate that the flow-ability characteristics have been increased as the waste glass incorporated to paste volume. Nevertheless, compressive, flexural and splitting strengths of concrete containing waste glass have been shown to decrease when the content of waste glass is increased. The strength reduction of concrete in different glass replacement ratios is not remarkable, thus it can be produced SCC with waste glass as fine aggregate in a standard manner.

关键词： Self Compacting Concrete (SCC) recycle glass fine aggregate fresh and hardened properties

HTML PDF 收藏

Effect of calcium lactate on compressive strength and self-healing of cracks in microbial concrete

Kunamineni VIJAY, Meena MURMU

《结构与土木工程前沿（英文）》 2019年第13卷第3期页码 515-525 doi: 10.1007/s11709-018-0494-2

摘要： This paper presents the effect on compressive strength and self-healing capability of bacterial concrete with the addition of calcium lactate. Compared to normal concrete, bacterial concrete possesses higher durability and engineering concrete properties. The production of calcium carbonate in bacterial concrete is limited to the calcium content in cement. Hence calcium lactate is externally added to be an additional source of calcium in the concrete. The influence of this addition on compressive strength, self-healing capability of cracks is highlighted in this study. The bacterium used in the study is and was added to both spore powder form and culture form to the concrete. spore powder of 2 million cfu/g concentration with 0.5% cement was mixed to concrete. Calcium lactates with concentrations of 0.5%, 1.0%, 1.5%, 2.0%, and 2.5% of cement, was added to the concrete mixes to test the effect on properties of concrete. In other samples, cultured with a concentration of 1×10 cells/mL was mixed with concrete, to study the effect of bacteria in the cultured form on the properties of concrete. Cubes of 100 mm×100 mm×100 mm were used for the study. These cubes were tested after a curing period of 7, 14 and 28 d. A maximum of 12% increase in compressive strength was observed with the addition of 0.5% of calcium lactate in concrete. Scanning electron microscope and energy dispersive X-ray spectroscopy examination showed the formation of ettringite in pores; calcium silicate hydrates and calcite which made the concrete denser. A statistical technique was applied to analyze the experimental data of the compressive strengths of cementations materials. Response surface methodology was adopted for optimizing the experimental data. The regression equation was yielded by the application of response surface methodology relating response variables to input parameters. This method aids in predicting the experimental results accurately with an acceptable range of error. Findings of this investigation indicated the influence of added calcium lactate in bio-concrete which is quite impressive for improving the compressive strength and self-healing properties of concrete.

关键词： calcium lactate bacillus subtilis compressive strength self-healing of cracks

HTML PDF 收藏

Computational fluid dynamic analysis of flutter characteristics for self-anchored suspension bridges

ZHU Zhiwen, WANG Zhaoxiang, CHEN Zhengqing

《结构与土木工程前沿（英文）》 2008年第2卷第3期页码 267-273 doi: 10.1007/s11709-008-0034-6

摘要： This paper outlines the essentials and procedures of computational fluid dynamics (CFD) simulation applicable to evaluating flutter derivatives of bridge decks. An arbitrary Lagrangian-Eulerian (ALE) description of the flow around the moving rigid box girder combined with the finite volume discretization and multi-grid algorithm is presented. The proposed methods are employed to identify flutter derivatives of the bridge deck of the Sanchaji Self-anchored Suspension Bridge. The results agree well with ones from wind tunnel tests. It demonstrates accuracy and efficiency of the present method.

关键词： discretization computational description Self-anchored Suspension simulation applicable

HTML PDF 收藏

Effects of solvents and temperature on spherulites of self-assembled phloroglucinol tristearate

Yawen Yao, Sabine Rosenfeldt, Kai Zhang

《化学科学与工程前沿（英文）》 2020年第14卷第3期页码 389-396 doi: 10.1007/s11705-019-1911-3

摘要： Herein, phloroglucinol tristearate (PhgTS) was used to study the crystallization process due to its unique symmetric structure containing a benzene ring and three aliphatic chains. Spherulites of crystallized PhgTS from four solvents under diverse conditions were analyzed in detail and their formation process was studied. Maltese cross is shown by PhgTS spherulites obtained from aprotic solvents via polarized optical microscopy. In comparison, no Maltese cross can be observed from branch-like crystals formed from protic solvents. Independent on the microscaled morphology, lamellae were found to be the basic blocks constructing both PhgTS spherulites and branch-like crystals, which were formed predominantly by stacked PhgTS molecules. Although differential characters of the solvents did not affect the formation of lamellas, the solvents played a crucial role in the formation of self-assembled microscaled morphologies. In particular, the morphologies of spherulites were strongly affected by the concentration of PhgTS solutions, surrounding temperature and evaporation rate of solvents. Generally, a higher concentration of PhgTS led to more homogeneous spherulites, a lower evaporation rate resulted in more compact spherulites, and a higher surrounding temperature generated preferentially more ring-banded spherulites of PhgTS.

关键词： phloroglucinol tristearate aprotic and protic solvent self-assembly spherulites