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 1729

会议视频 45

年份

2024 4

2023 141

2022 180

2021 157

2020 145

2019 131

2018 103

2017 102

2016 75

2015 90

2014 59

2013 54

2012 40

2011 46

2010 52

2009 56

2008 66

2007 77

2006 48

2005 34

展开︾

关键词

遗传算法 9

优化 7

神经网络 7

医学 5

可持续发展 5

智能制造 5

信息技术 4

多目标优化 4

机器学习 4

目标识别 4

能源 4

预测 4

BP神经网络 3

COVID-19 3

人工智能 3

工程管理 3

环境 3

算法 3

ANSYS 2

展开︾

检索范围：

排序：展示方式：

Adaptive selective ES-FEM limit analysis of cracked plane-strain structures

H. NGUYEN-XUAN,T. RABCZUK

《结构与土木工程前沿（英文）》 2015年第9卷第4期页码 478-490 doi: 10.1007/s11709-015-0317-7

摘要： This paper presents a simple and efficient approach for predicting the plastic limit loads in cracked plane-strain structures. We use two levels of mesh repartitioning for the finite element limit analysis. The master level handles an adaptive primal-mesh process through a dissipation-based indicator. The slave level performs the subdivision of each triangle into three sub-triangles and constitutes a dual mesh from a pair of two adjacent sub-triangles shared by common edges of the primal mesh. Applying a strain smoothing projection to the strain rates on the dual mesh, the incompressibility constraint and the flow rule constraint are imposed over the edge-based smoothing domains and everywhere in the problem domain. The limit analysis problem is recast into the compact form of a second-order cone programming (SOCP) for the purpose of exploiting interior-point solvers. The present method retains a low number of optimization variables. It offers a convenient way for designing and solving the large-scale optimization problems effectively. Several benchmark examples are given to show the simplicity and effectiveness of the present method.

关键词： cracked structure limit analysis von Mises criterion edge-based strain smoothing second-order cone programming adaptive

HTML PDF 收藏

The smoothed finite element method (S-FEM): A framework for the design of numerical models for desired solutions

Gui-Rong Liu

《结构与土木工程前沿（英文）》 2019年第13卷第2期页码 456-477 doi: 10.1007/s11709-019-0519-5

摘要：

The smoothed finite element method (S-FEM) was originated by G R Liu by combining some meshfree techniques with the well-established standard finite element method (FEM). It has a family of models carefully designed with innovative types of smoothing domains. These models are found having a number of important and theoretically profound properties. This article first provides a concise and easy-to-follow presentation of key formulations used in the S-FEM. A number of important properties and unique features of S-FEM models are discussed in detail, including 1) theoretically proven softening effects; 2) upper-bound solutions; 3) accurate solutions and higher convergence rates; 4) insensitivity to mesh distortion; 5) Jacobian-free; 6) volumetric-locking-free; and most importantly 7) working well with triangular and tetrahedral meshes that can be automatically generated. The S-FEM is thus ideal for automation in computations and adaptive analyses, and hence has profound impact on AI-assisted modeling and simulation. Most importantly, one can now purposely design an S-FEM model to obtain solutions with special properties as wish, meaning that S-FEM offers a framework for design numerical models with desired properties. This novel concept of numerical model on-demand may drastically change the landscape of modeling and simulation. Future directions of research are also provided.

关键词： computational method finite element method smoothed finite element method strain smoothing technique smoothing domain weakened weak form solid mechanics softening effect upper bound solution

HTML PDF 收藏

Concepts and implementation of strain-based criteria in design codes for steel structures

Reidar BJORHOVDE

《结构与土木工程前沿（英文）》 2012年第6卷第3期页码 210-216 doi: 10.1007/s11709-012-0165-7

摘要： A uniaxial tension test is commonly used to determine the mechanical properties of steel, but it has no meaning for the response of the material in a structure. The test was developed as a consensus solution by producers, fabricators, designers and code writers, to have a standard by which similar materials could be compared to a common base. It does not represent the actual behavior of the steel in a structure, and was never intended to do so. To study the true behavior of the structure and how the material responds it would be better to determine the strains and deformations that will take place during actual service condition. Such characteristics reflect the real behavior, whether in the elastic or inelastic range. If stresses or forces are needed, these are easily determined by the value of the strain and the relevant material modulus, along with the type of cross section, whether elastic or inelastic. The paper addresses the properties of a range of structural steels, how these are incorporated into design standards and how the standards define deformation characteristics and demands for bolted and welded connections.

关键词： steel stress-strain characteristics tension test strain design actual behavior improved design codes

HTML PDF 收藏

Real-time task processing method based on edge computing for spinning CPS

Shiyong YIN, Jinsong BAO, Jie LI, Jie ZHANG

《机械工程前沿（英文）》 2019年第14卷第3期页码 320-331 doi: 10.1007/s11465-019-0542-1

摘要： Spinning production is a typical continuous manufacturing process characterized by high speed and uncertain dynamics. Each manufacturing unit in spinning production produces various real-time tasks, which may affect production efficiency and yarn quality if not processed in time. This paper presents an edge computing-based method that is different from traditional centralized cloud computation because its decentralization characteristics meet the high-speed and high-response requirements of yarn production. Edge computing nodes, real-time tasks, and edge computing resources are defined. A system model is established, and a real-time task processing method is proposed for the edge computing scenario. Experimental results indicate that the proposed real-time task processing method based on edge computing can effectively solve the delay problem of real-time task processing in spinning cyber-physical systems, save bandwidth, and enhance the security of task transmission.

关键词： edge computing real-time task scheduling CPS spinning

HTML PDF 收藏

Smoothing ramp events in wind farm based on dynamic programming in energy internet

Jiang LI, Guodong LIU, Shuo ZHANG

《能源前沿（英文）》 2018年第12卷第4期页码 550-559 doi: 10.1007/s11708-018-0593-8

摘要：

The concept of energy internet has been gradually accepted, which can optimize the consumption of fossil energy and renewable energy resources. When wind power is integrated into the main grid, ramp events caused by stochastic wind power fluctuation may threaten the security of power systems. This paper proposes a dynamic programming method in smoothing ramp events. First, the energy internet model of wind power, pumped storage power station, and gas power station is established. Then, the optimization problem in the energy internet is transformed into a multi-stage dynamic programming problem, and the dynamic programming method proposed is applied to solve the optimization problem. Finally, the evaluation functions are introduced to evaluate pollutant emissions. The results show that the dynamic programming method proposed is effective for smoothing wind power and reducing ramp events in energy internet.

关键词： energy internet wind power ramp events dynamic programming

HTML PDF 收藏

Application of a Novel Fuzzy Clustering Method Based on Chaos Immune Evolutionary Algorithm for Edge

《机械工程前沿（英文）》 2006年第1卷第1期页码 85-89 doi: 10.1007/s11465-005-0023-6

摘要：

A novel fuzzy clustering method based on chaos immune evolutionary algorithm (CIEFCM) is presented to solve fuzzy edge detection problems in image processing. In CIEFCM, a tiny disturbance is added to a filial generation group using a chaos variable and the disturbance amplitude is adjusted step by step, which greatly improves the colony diversity of the immune evolution algorithm (IEA). The experimental results show that the method not only can correctly detect the fuzzy edge and exiguous edge but can evidently improve the searching efficiency of fuzzy clustering algorithm based on IEA.

关键词： disturbance amplitude disturbance diversity generation processing

HTML PDF 收藏

FEM-based strain analysis study for multilayer sheet forming process

Rongjing ZHANG,Lihui LANG,Rizwan ZAFAR

《机械工程前沿（英文）》 2015年第10卷第4期页码 373-379 doi: 10.1007/s11465-015-0371-9

摘要：

Fiber metal laminates have many advantages over traditional laminates (e.g., any type of fiber and resin material can be placed anywhere between the metallic layers without risk of failure of the composite fabric sheets). Furthermore, the process requirements to strictly control the temperature and punch force in fiber metal laminates are also less stringent than those in traditional laminates. To further explore the novel method, this study conducts a finite element method-based (FEM-based) strain analysis on multilayer blanks by using the 3A method. Different forming modes such as wrinkling and fracture are discussed by using experimental and numerical studies. Hydroforming is used for multilayer forming. The Barlat 2000 yield criteria and DYNAFORM/LS-DYNA are used for the simulations. Optimal process parameters are determined on the basis of fixed die-binder gap and variable cavity pressure. The results of this study will enhance the knowledge on the mechanics of multilayer structures formed by using the 3A method and expand its commercial applications.

关键词： finite element method (FEM) strain analysis multilayer sheet forming

HTML PDF 收藏

Multiple damage detection in complex bridges based on strain energy extracted from single point measurement

Alireza ARABHA NAJAFABADI, Farhad DANESHJOO, Hamid Reza AHMADI

《结构与土木工程前沿（英文）》 2020年第14卷第3期页码 722-730 doi: 10.1007/s11709-020-0624-5

摘要： Strain Energy of the structure can be changed with the damage at the damage location. The accurate detection of the damage location using this index in a force system is dependent on the degree of accuracy in determining the structure deformation function before and after damage. The use of modal-based methods to identify damage in complex bridges is always associated with problems due to the need to consider the effects of higher modes and the adverse effect of operational conditions on the extraction of structural modal parameters. In this paper, the deformation of the structure was determined by the concept of influence line using the Betti-Maxwell theory. Then two damage detection indicators were developed based on strain energy variations. These indices were presented separately for bending and torsion changes. Finite element analysis of a five-span concrete curved bridge was done to validate the stated methods. Damage was simulated by decreasing stiffness at different sections of the deck. The response regarding displacement of a point on the deck was measured along each span by passing a moving load on the bridge at very low speeds. Indicators of the strain energy extracted from displacement influence line and the strain energy extracted from the rotational displacement influence line (SERIL) were calculated for the studied bridge. The results show that the proposed methods have well identified the location of the damage by significantly reducing the number of sensors required to record the response. Also, the location of symmetric damages is detected with high resolution using SERIL.

关键词： damage detection strain energy influence line complex bridges rotation displacement

HTML PDF 收藏

A three-dimensional two-level gradient smoothing meshfree method for rainfall induced landslide simulations

Dongdong WANG, Jiarui WANG, Junchao WU, Junjun DENG, Ming SUN

《结构与土木工程前沿（英文）》 2019年第13卷第2期页码 337-352 doi: 10.1007/s11709-018-0467-5

摘要： A three-dimensional two-level gradient smoothing meshfree method is presented for rainfall induced landslide simulations. The two-level gradient smoothing for meshfree shape function is elaborated in the three-dimensional Lagrangian setting with detailed implementation procedure. It is shown that due to the successive gradient smoothing operation without the requirement of derivative computation in the present formulation, the two-level smoothed gradient of meshfree shape function is capable of achieving a given influence domain more efficiently than the standard gradient of meshfree shape function. Subsequently, the two-level smoothed gradient of meshfree shape function is employed to discretize the weak form of coupled rainfall seepage and soil motion equations in a nodal integration format, as provides an efficient three-dimensional regularized meshfree formulation for large deformation rainfall induced landslide simulations. The exponential damage and pressure dependent plasticity relationships are utilized to describe the failure evolution in landslides. The plastic response of soil is characterized by the true effective stress measure, which is updated according to the rotationally neutralized objective integration algorithm. The effectiveness of the present three-dimensional two-level gradient smoothing meshfree method is demonstrated through numerical examples.

关键词： meshfree method landslide rainfall three-dimensional two-level gradient smoothing nodal integration

HTML PDF 收藏

应用指数平滑技术预测边坡位移

沈良峰

《中国工程科学》 2007年第9卷第6期页码 94-97

摘要：

应用趋势型指数平滑模型根据其观测值的数据特点（具线性趋势），选取趋势型二次指数平滑的线性预测公式和相应at，bt的计算公式及合适的平滑系数值进行计算，预测了某市滑坡区５号监测点的位移量。预测结果表明，该方法应用于斜坡变形位移的预测，可使预测值与实际位移值之间的误差很小。

关键词：指数平滑预测边坡位移自适应过滤

HTML PDF 收藏

Edge preparation methods for cutting tools: a review

《机械工程前沿（英文）》 2023年第18卷第4期 doi: 10.1007/s11465-023-0766-y

摘要： Edge preparation can remove cutting edge defects, such as burrs, chippings, and grinding marks, generated in the grinding process and improve the cutting performance and service life of tools. Various edge preparation methods have been proposed for different tool matrix materials, geometries, and application requirements. This study presents a scientific and systematic review of the development of tool edge preparation technology and provides ideas for its future development. First, typical edge characterization methods, which associate the microgeometric characteristics of the cutting edge with cutting performance, are briefly introduced. Then, edge preparation methods for cutting tools, in which materials at the cutting edge area are removed to decrease defects and obtain a suitable microgeometry of the cutting edge for machining, are discussed. New edge preparation methods are explored on the basis of existing processing technologies, and the principles, advantages, and limitations of these methods are systematically summarized and analyzed. Edge preparation methods are classified into two categories: mechanical processing methods and nontraditional processing methods. These methods are compared from the aspects of edge consistency, surface quality, efficiency, processing difficulty, machining cost, and general availability. In this manner, a more intuitive understanding of the characteristics can be gained. Finally, the future development direction of tool edge preparation technology is prospected.

关键词： edge preparation method preparation principle cutting edge geometry edge characterization tool performance

HTML PDF 收藏

Surficial stability analysis of soil slope under seepage based on a novel failure mode

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 712-726 doi: 10.1007/s11709-021-0729-5

摘要： Normally, the edge effects of surficial landslides are not considered in the infinite slope method for surficial stability analysis of soil slopes. In this study, the limit stress state and discrimination equation of an infinite slope under saturated seepage flow were analyzed based on the Mohr-Coulomb strength criterion. Therefore, a novel failure mode involving three sliding zones (upper tension zone, middle shear sliding zone, and lower compression zone) was proposed. Accordingly, based on the limit equilibrium analysis, a semi-analytical framework considering the edge effect for the surficial stability of a soil slope under downslope seepage was established. Subsequently, the new failure mode was verified via a numerical finite element analysis based on the reduced strength theory with ABAQUS and some simplified methods using SLIDE software. The results obtained by the new failure mode agree well with those obtained by the numerical analysis and traditional simplified methods, and can be efficiently used to assess the surficial stability of soil slopes under rainwater seepage. Finally, an evaluation of the infinite slope method was performed using the semi-analytical method proposed in this study. The results show that the infinite slope tends to be conservative because the edge effect is neglected, particularly when the ratio of surficial slope length to depth is relatively small.

关键词： soil slope seepage surficial failure mode stress state edge effects

HTML PDF 收藏

Structural design of morphing trailing edge actuated by SMA

Qi WANG, Zhiwei XU, Qian ZHU

《机械工程前沿（英文）》 2013年第8卷第3期页码 268-275 doi: 10.1007/s11465-013-0261-y

摘要：

In this paper, the morphing trailing edge is designed to achieve the up and down deflection under the aerodynamic load. After a detailed and accurate computational analysis to determine the SMA specifications and layout programs, a solid model is created in CATIA and the structures of the morphing wing trailing edge are produced by CNC machining. A set of DSP measurement and control system is designed to accomplish the controlling experiment of the morphing wing trailing edge. At last, via the force analysis, the trailing edge is fabricated with four sections of aluminum alloy, and the arrangement scheme of SMA wires is determined. Experiment of precise control integral has been performed to survey the control effect. The experiment consists of deflection angle tests of the third joint and the integral structure. Primarily, the ultimate deflection angle is tested in these two experiments. Therefore, the controlling experiment of different angles could be performed within this range. The results show that the deflection error is less than 4% and response time is less than 6.7 s, the precise controlling of the morphing trailing edge is preliminary realized.

关键词： morphing wing trailing edge shape memory alloy digital signal processor PID algorithm

HTML PDF 收藏

Frequencies of circular plate with concentric ring and elastic edge support

null

《机械工程前沿（英文）》 2014年第9卷第2期页码 168-176 doi: 10.1007/s11465-014-0299-5

摘要：

Exact solutions for the flexural vibrations of circular plates having elastic edge conditions along with rigid concentric ring support have been presented in this paper. Values of frequency parameter for the considered circular plate are computed for different sets of values of elastic rotational and translation restraints and the radius of internal rigid ring support. The results for the first three modes of plate vibrations are computed and are presented in tabular form. The effects of rotational and linear restraints and the radius of the rigid ring support on the vibration behavior of circular plates are studied over a wide range of non-dimensional parametric values. The values of the exact frequency parameter presented in this paper for varying values of restraint parameters and the radius of the rigid ring support can better serve in design and as benchmark solutions to validate the numerical methods obtained by using other methods of solution.

关键词： circular plate frequency elastic edge rigid ring mode switching

HTML PDF 收藏

Knife-edge technique for laser cooling

WANG Zhanshan, MA Shanshan, MA Yan, ZHAO Min, LIU Hengbiao

《机械工程前沿（英文）》 2007年第2卷第4期页码 468-473 doi: 10.1007/s11465-007-0081-z

摘要： The transfer characteristics of an atomic beam and the effect of laser were investigated in this paper. In the application of knife-edge technique, the temperature of atoms through laser cooling was measured. Results indicate that, after atoms are emitted from an atomic oven, the longer the atoms move, the worse the distribution of the atomic beam shows, regardless the laser cooling is taken or not. Laser cooling can reduce the transverse velocity of the atomic beam to several orders of magnitude and also increase the uniformity of an atomic beam. Knife-edge technique can measure the temperature of an atomic beam through laser cooling. The measurement accuracy depends on the pixel size of the charge coupled device (CCD), which is used for the fluorescent imaging of the atomic beam. The results are very important for the future experiments of laser cooling.

关键词： knife-edge technique uniformity coupled transfer fluorescent