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 489

会议视频 25

会议信息 2

年份

2024 1

2023 45

2022 43

2021 53

2020 27

2019 25

2018 29

2017 16

2016 25

2015 23

2014 17

2013 17

2012 18

2011 24

2010 20

2009 29

2008 14

2007 18

2006 12

2005 7

展开︾

关键词

钢结构 8

建筑科学 7

三峡工程 3

优化设计 3

耐久性 3

飞机结构 3

DSM（设计结构矩阵） 2

Quantitative structure 2

imge analysis 2

stereology 2

产业结构 2

关键技术 2

压力容器技术 2

可持续发展 2

城镇建设 2

机械结构 2

疲劳寿命 2

结构调整 2

能源结构 2

展开︾

检索范围：

排序：展示方式：

Image analyses for video-based remote structure vibration monitoring system

Yang YANG,Xiong (Bill) YU

《结构与土木工程前沿（英文）》 2016年第10卷第1期页码 12-21 doi: 10.1007/s11709-016-0313-6

摘要： Video-based vibration measurement is a cost-effective way for remote monitoring the health conditions of transportation and other civil structures, especially for situations where accessibility is restricted and does not allow installation of conventional monitoring devices. Besides, video-based system is global measurement. The technical basis of video-based remote vibration measurement system is digital image analysis. Comparison of the images allow the field of motion to be accurately delineated. Such information is important to understand the structure behaviors including the motion and strain distribution. This paper presents system and analyses to monitor the vibration velocity and displacement field. The performance is demonstrated on a testbed of model building. Three different methods (i.e., frame difference method, particle image velocimetry, and optical Flow Method) are utilized to analyze the image sequences to extract the feature of motion. The Performance is validated using accelerometer data. The results indicate that all three methods can estimate the velocity field of the model building, although the results can be affected by factors such as background noise and environmental interference. Optical flow method achieved the best performance among these three methods studied. With further refinement of system hardware and image processing software, it will be developed into a remote video based monitoring system for structural health monitoring of transportation infrastructure to assist the diagnoses of its health conditions.

关键词： structure health monitoring velocity estimation frame difference PIV optical-flow method

HTML PDF 收藏

The convexity about ultimate bearing hypersurfaces of structures

Chengxi GUO,Tingting GUO

《结构与土木工程前沿（英文）》 2016年第10卷第4期页码 456-461 doi: 10.1007/s11709-016-0334-1

摘要： The relationship between the convexity on the ultimate bearing surface of a structure and the second-order effects of loads is discussed. All of generalized non-overload forces acted on a structure forms a convex set when ignoring the second-order effects (coupling effects between the generalized forces). It is true also when the Hessian matrix composed of the second-order partial derivatives on the hypersurface about the ultimate bearing of the structure is negative definite. The outward convexity is kept when the surface is expressed by certain dimensionless parameters. A series of properties based on the convexity are pointed out. Some applications in the analysis of bearing capacity of structures were illustrated with examples. The study shows that an evaluation about the bearing capacity state of a complex structure can be made on the basis of several points on the surface of the ultimate bearing of the structure.

关键词： service limit load ultimate bearing surface convexity generalized force generalized displacement frame structure

HTML PDF 收藏

设计创新对东方明珠和雅加达塔的贡献

江欢成

《中国工程科学》 1999年第1卷第1期页码 30-35

摘要：

东方明珠，塔高463.85m，高居亚洲之二，世界第三，被公认为是上海最重要的城市标志。雅加达塔，高558m，建筑面积32万m²，均堪称世界之最。东方明珠的成功，雅加达塔的中标，在很大程度上要归功于设计创新。东方明珠设计者用一串明珠来标志上海，用带斜撑的巨型空间框架作为主体结构，打破了混凝土电视塔常用的单筒体结构模式，从而获得了很好的标志性。这种结构同时很有利于抗风抗震。该塔还采用了许多高新技术，如预应力混凝土壳、双重悬挂钢结构和攀升天线等设计，它们巧妙而合理地解决了复杂的结构构造和高难度施工的问题。设计者在雅加达塔上，继承和发扬东方明珠的长处，克服它的不足，并赋予许多新的创造。为了使新的创造建立在坚实科学基础上，设计者为东方明珠塔进行了大量的试验研究工作。

关键词：创新电视塔空间框架斜撑球体钢桅杆悬挂结构

HTML PDF 收藏

论安全科学技术学科体系的结构和内涵

傅贵,张江石,许素睿

《中国工程科学》 2004年第6卷第8期页码 12-16

摘要：

安全科学技术学科作为《学科分类与代码》的一个一级学科，有明确的研究对象——事故，其研究目的是事故预防和控制事故损失。该学科以事故的发生发展规律为基础科学，它与不同的研究手段和工具交叉形成了该学科的应用科学体系。根据研究范围的不同，安全学科在不同的领域又形成了一个分支学科体系，但研究方法和工具仍然是相同的。就作者的鉴别能力和学科发展现状来说，安全科学技术学科的结构由至少6个基础概念、3条公理组成，学科的科学结构基本完整。

关键词：安全科学技术学科内涵研究对象事故预防基础概念公理

HTML PDF 收藏

Seismic performance of moment resisting steel frame subjected to earthquake excitations

Fadzli M. NAZRI, Pang Yew KEN

《结构与土木工程前沿（英文）》 2014年第8卷第1期页码 19-25 doi: 10.1007/s11709-014-0240-3

摘要： This study presents static and dynamic assessments on the steel structures. Pushover analysis (POA) and incremental dynamic analysis (IDA) were run on moment resisting steel frames. The IDA study involves successive scaling and application of each accelerogram followed by assessment of the maximum response. Steel frames are subjected to nonlinear inelastic time history analysis for 14 different scaled ground motions, 7 near field and 7 far field. The results obtained from POA on the 3, 6 and 9 storey steel frames show consistent results for both uniform and triangular lateral loading. Uniform loading shows that the steel frames exhibits higher base shear than the triangular loading. The IDA results show that the far field ground motions has caused all steel frame design within the research to collapse while near field ground motion only caused some steel frames to collapse. The POA can be used to estimate the performance-based-seismic-design (PBSD) limit states of the steel frames with consistency while the IDA seems to be quite inconsistent. It is concluded that the POA can be consistently used to estimate the limit states of steel frames while limit state estimations from IDA requires carefully selected ground motions with considerations of important parameters.

关键词： incremental dynamic analysis (IDA) pushover analysis performance-based seismic design

HTML PDF 收藏

Development of rocking constraint device with vertical damping capacity for three-dimensional base-isolated frame

《结构与土木工程前沿（英文）》 2023年第17卷第3期页码 350-367 doi: 10.1007/s11709-022-0923-0

摘要： A new rocking constraint device (RCD) is developed for three-dimensional (3D) base-isolated frame structures by connecting a custom-designed cylinder pair to provide vertical damping with replaceable damping components installed outside the cylinders when the superstructure undergoes translational motion, and rocking constraint capacity when the superstructure is susceptible to rocking. Theoretical formulas for calculating the damping and rocking constraint stiffness of the RCD are proposed. Two series of sinusoidal loading tests are conducted at different loading frequencies and amplitudes to verify the damping and rocking constraint performance of the RCD. The test results show that the cylinder without orifices on its piston can provide the desired damping with a replaceable damping component, and that the RCD can effectively suppress rocking. Although the vertical stiffness of an individual cylinder is affected by the location of the replaceable damping component and loading frequency, the average vertical stiffness of the two cylinders, which determines the rocking constraint stiffness of the RCD, is independent of the two factors. Comparisons of the test and theoretical results indicate that the errors of the proposed formulas for calculating the damping and rocking constraint stiffness of the RCD do not exceed 12.9% and 11.0%, respectively.

关键词： three-dimensional isolation rocking behavior rocking constraint device replaceable damping component sinusoidal test

HTML PDF 收藏

Seismic tests of post-tensioned self-centering building frames with column and slab restraints

Chung-Che CHOU, Jun-Hen CHEN

《结构与土木工程前沿（英文）》 2011年第5卷第3期页码 323-334 doi: 10.1007/s11709-011-0119-5

摘要： Post-tensioned (PT) self-centering moment frames have been developed as an alternative to typical moment-resisting frames (MRFs) for earthquake resistance. When a PT frame deforms laterally, gaps between the beams and columns open. However, the gaps are constrained by the columns and the slab in a real PT self-centering building frame. This paper presents a methodology for evaluating the column restraint and beam compression force based on the column deformation and gap openings at all stories. The method is verified by cyclic tests of a full-scale, two-bay by one-story PT frame. Moreover, a sliding slab is proposed to minimize restraints on the expansion of the PT frame. Shaking table tests were conducted on a reduced-scale, two-by-two bay one-story specimen, which comprises one PT frame and two gravitational frames. The PT frame and gravitational frames are self-centering throughout the tests, responding in phase with only minor differences in peak drifts caused by expansion of the PT frame. When the specimen is excited by a simulation of the 1999 Chi-Chi earthquake with a peak ground acceleration of 1.87 g, the maximum interstory drift and the residual drift are 7.2% and 0.01%, respectively.

关键词： post-tensioned frame frame expansion column restraint sliding slab frame test shake table test

HTML PDF 收藏

Tests on impact effect of partial fracture at steel frame connections

CHEN Yiyi, BIAN Ruoning

《结构与土木工程前沿（英文）》 2008年第2卷第4期页码 295-301 doi: 10.1007/s11709-008-0049-z

摘要： Impact effect of sudden fracture at steel frame connections under severe earthquake or other extreme loads is presented in this paper. The relation of impulse caused by structural fracture to the release of inner force at the cracked location, the magnitude of the response to impact on the basis of one degree of freedom model, and the ratio of the peak value of response to natural period of the system are investigated. Two types of fracture tests were designed and carried out both on uniaxial steel bar tensioned and moment resistant steel frame model. It is proven that the response during the fracture process can be measured quite well using high-frequency data processing system. It is also revealed that the instant fracture of structural connection is characterized by progressive and partial fracture. Numerical evaluation of the impact effect of connection fracture is carried out.

关键词： structural fracture natural fracture progressive high-frequency

HTML PDF 收藏

Deep reinforcement learning-based critical element identification and demolition planning of frame structures

Shaojun ZHU; Makoto OHSAKI; Kazuki HAYASHI; Shaohan ZONG; Xiaonong GUO

《结构与土木工程前沿（英文）》 2022年第16卷第11期页码 1397-1414 doi: 10.1007/s11709-022-0860-y

摘要： This paper proposes a framework for critical element identification and demolition planning of frame structures. Innovative quantitative indices considering the severity of the ultimate collapse scenario are proposed using reinforcement learning and graph embedding. The action is defined as removing an element, and the state is described by integrating the joint and element features into a comprehensive feature vector for each element. By establishing the policy network, the agent outputs the Q value for each action after observing the state. Through numerical examples, it is confirmed that the trained agent can provide an accurate estimation of the Q values, and handle problems with different action spaces owing to utilization of graph embedding. Besides, different behaviors can be learned by varying hyperparameters in the reward function. By comparing the proposed method and the conventional sensitivity index-based methods, it is demonstrated that the computational cost is considerably reduced because the reinforcement learning model is trained offline. Besides, it is proved that the Q values produced by the reinforcement learning agent can make up for the deficiencies of existing indices, and can be directly used as the quantitative index for the decision-making for determining the most expected collapse scenario, i.e., the sequence of element removals.

关键词： progressive collapse alternate load path demolition planning reinforcement learning graph embedding

HTML PDF 收藏

Effect of RC wall on the development of plastic rotation in the beams of RC frame structures

Amar KAHIL, Aghiles NEKMOUCHE, Said BOUKAIS, Mohand HAMIZI, Naceur Eddine HANNACHI

《结构与土木工程前沿（英文）》 2018年第12卷第3期页码 318-330 doi: 10.1007/s11709-017-0420-z

摘要：

The objective of this study is, to interpret the influence of reinforced concrete walls addition in reinforced concrete frame structures considering behavior laws that reflects the actual behavior of such structures, by means of Castem2000computer code (pushover analysis). A finite element model is proposed in this study, using the TAKEDA modified behavior model with Timoshenko beams elements. This model is validated initially on experimental model. Then the work has focused on the behavior of a RC frame with 3 levels and three bays to better visualize the behavior of plastic hinges. Once the plastic hinge control parameters are identified (plastic rotation, ultimate curvature), a strengthening by introduction of reinforced concrete walls (RC/wall) at the ends of the reinforced concrete frame (RC/frame) has been performed. The results show that these RC walls significantly improve the behavior, by a relocation of efforts towards the central part of the beams.

关键词： RC/frame RC/wall moment curvature plastic rotation plastic hinge pushover analysis global models

HTML PDF 收藏

Seismic behavior experimental study of frame joints with special-shaped column and dispersed steel bar

Shuchun LI, Bo DIAO, Youpo SU,

《结构与土木工程前沿（英文）》 2009年第3卷第4期页码 378-383 doi: 10.1007/s11709-009-0064-8

摘要： To overcome the problem that steel bars are put too close at a flame joint with special-shaped beam and column, mechanical performance of three groups of six RC flame joints with special-shaped (L, T and+) column and dispersed-steel bars-beam on the top floor under cyclic loads were studied. Experimental comparison was conducted between special-shaped (L, T and+) column and normal beams. The cracking load, yielding load, ultimate bearing capacity, failure patterns, and hysteretic properties at joint core area were investigated. The seismic behaviors of the joints with different proportions of dispersed-steel-bar beams were analyzed. The results of experimental analysis indicate that the mechanical and seismic behaviors of frame joints with T-shaped and+-shaped column are nearly not changed when suitable proportion steel bars are dispersed to flange plane. Stiffness degeneration of flame joint with L-shaped column is rather serious due to concrete damage stiffness. Theoretical result indicates that distributing area of the dispersed steel-bar beams in the flange plate should be strictly controlled to avoid anchor destroy.

关键词： beam with dispersed steel bar flame joints with special-shaped beam and column seismic behavior scale of dispersed steel bars

HTML PDF 收藏

Truss-arch model for shear strength of seismic-damaged SRC frame columns strengthened with CFRP sheets

Sheng PENG, Chengxiang XU, Xiaoqiang LIU

《结构与土木工程前沿（英文）》 2019年第13卷第6期页码 1324-1337 doi: 10.1007/s11709-019-0557-z

摘要： Carbon fiber reinforced polymer (CFRP) materials are important reinforcing substances which are widely used in the shear strengthening of seismic-damage steel reinforced concrete (SRC) frame structures. To investigate the shear strength of SRC frame columns strengthened with CFRP sheets, experimental observations on eight seismic-damaged SRC frame columns strengthened with CFRP sheets were conducted at Yangtze University and existing experimental data of 49 SRC columns are presented. Based on the existing experiments, the theories of damage degree, zoning analysis of concrete, and strengthening material of the column are adopted. To present the expression formula of the shear strength of SRC frame columns strengthened with CFRP sheets, the contributions of strengthening material and transverse reinforcement to shear strength in the truss model are considered, based on the truss-arch model. The contribution of arch action is also considered through the analysis of the whole concrete and that of the three zones of the concrete are also considered. The formula is verified, and the calculated results are found to match well with the experimental results. Results indicate that the proposed whole analysis model can improve the accuracy of shear strength predictions of shear seismic-damaged SRC frame columns reinforced with CFRP sheets.

关键词： carbon fiber reinforced polymer material steel reinforced concrete frame column seismic-damaged trussed-arch model shear strength

HTML PDF 收藏

视频分层组织方案和技术

章毓晋,陆海斌

《中国工程科学》 2000年第2卷第3期页码 18-22

摘要：

数字视频是多媒体信息系统中重要的数据类型。传统的视频表示方法仅是一个时间序列一媒体流，所以对计算机来说，很难在内容层次上认知视频。为了有效地访问和利用视频信息，合适的视频数据组织非常重要。文章提出将视频划分成四个层次即视频节目、情节、镜头和图像帧的组织方法。这样一种分层结构提供了紧凑和有意义的视频目录，方便了视频非线性浏览和基于内容的检索。为了得到这样一种组织，不仅要检测出镜头和情节这些视频单元的边界，还要提取镜头关键帧和选择情节有代表性的镜头和代表帧。文章介绍一系列分割视频和组织视频的准则和方法，并把它们结合起来组成了一个原型实验系统。文中还给出了一些对实际视频进行组织的结果，它们表明该组织形式是非常有效的。

关键词：视频组织浏览镜头关键帧情节代表帧

HTML PDF 收藏

扫描格式转换的自适应帧频提升算法及其FPGA实现

吴勇,张光烈,郑南宁,张霞

《中国工程科学》 2001年第3卷第4期页码 56-62

摘要：

文章提出了一种新的自适应帧频提升算法，并深人研究了它的快速硬件实现方法。该算法通过引入内部参数和加权块匹配误差，来进行自适应运动补偿，因而它可以有效地消除噪声的影响，并便于硬件实现。最后，通过建立对应于可变参数的因子査找表和采用现场可编程逻辑器件（FPGA)快速实现了扫描格式转换中的帧频提升算法，并应用在实际系统中，实验结果表明该算法十分有效。

关键词：扫描格式转换帧频提升块匹配运动补偿

HTML PDF 收藏

Experimental research on seismic behavior of recycled concrete frame under varying cyclic loading

SUN Yuedong, XIAO Jianzhuang, ZHOU Deyuan

《结构与土木工程前沿（英文）》 2008年第2卷第4期页码 302-308 doi: 10.1007/s11709-008-0050-6

摘要： A study is conducted on the seismic behavior of one natural concrete frame and two recycled concrete frames with 100% recycled coarse aggregate whose scales are 1:2 entirely, and a comparative study is conducted under low-reversed cyclic lateral loading and different vertical loading. This work aims to estimate the failure mechanism, hysteresis loops, displacement ductility, deterioration of strength and stiffness and energy dissipation of recycled concrete frames under low-reversed cyclic loading as well as the influence of different vertical loading. Analysis on the basis of the experiment proves that it is entirely feasible to apply recycled concrete to practical engineering for the sake of its good seismic behaviors. Theoretical base is provided for further study and practical application of recycled concrete structure.

关键词： different aggregate stiffness practical application % recycled