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 38

年份

2023 2

2022 7

2021 3

2020 3

2019 1

2018 1

2016 4

2014 1

2012 2

2011 1

2010 2

2009 2

2008 2

2005 2

2004 1

2003 1

2001 2

展开︾

关键词

发展 2

析出强化 2

1) 1

21世纪海上丝绸之路 1

F-B双相钢 1

GM(1 1

HSLC钢 1

PBO纤维片材 1

TiC 1

中国 1

中国特色 1

临床医学 1

井壁稳定 1

产业用化纤材料 1

仿生纺丝 1

低成本 1

保压 1

公共卫生 1

冷轧基板 1

展开︾

检索范围：

排序：展示方式：

Strengthening of reinforced concrete beams using fiber-reinforced cementitious matrix systems fabricated

《结构与土木工程前沿（英文）》页码 1100-1116 doi: 10.1007/s11709-023-0967-9

摘要： The performance of a new fiber-reinforced cementitious matrix (FRCM) system developed using custom-designed mortar and fabrics is investigated in this study. The behavior of this system is evaluated in terms of both the flexural and shear strengthening of reinforced concrete beams. Eight beams are designed to assess the effectiveness of the FRCM system in terms of flexural strengthening, and four specimens are designed to investigate their shear behavior. The parameters investigated for flexural strengthening are the number of layers, span/depth ratio, and the strengthening method. Unlike previous studies, custom fabrics with similar axial stiffness are used in all strengthening methods in this study. In the shear-strengthened specimens, the effects of the span/depth ratio and strengthening system type (fiber-reinforced polymer (FRP) or FRCM) are investigated. The proposed FRCM system exhibits desirable flexural and shear strengthening for enhancing the load capacity, provides sufficient bonding with the substrate, and prevents premature failure modes. Considering the similar axial stiffness of fabrics used in both FRCM and FRP systems and the higher load capacity of specimens strengthened by the former, cement-based mortar performs better than epoxy.

关键词： fiber-reinforced cementitious matrix flexural strengthening shear strengthening carbon fiber-reinforced polymer shear span

HTML PDF 收藏

一类新的强化缓冲算子及其数值仿真

崔杰,党耀国,刘思峰,谢乃明

《中国工程科学》 2010年第12卷第2期页码 108-112

摘要：

根据新信息优先利用原理，在已有强化缓冲算子研究的基础上，构造一类新的强化缓冲算子，同时研究了它们的一些特性，克服了原有强化缓冲算子对序列新信息利用不够充分的缺陷，有效地解决了冲击扰动数据序列在建模型预测过程中常常出现的定量预测结果与定性分析结论不符的问题,算例仿真表明：与已有强化算子相比，这类新的强化缓冲算子显著地提高了GM(1,1)模型的预测精度。

关键词：算子强化缓冲算子几何平均强化算子 GM(1 1)

HTML PDF 收藏

Shear strength model of the reinforced concrete beams with embedded through-section strengthening bars

Linh Van Hong BUI; Phuoc Trong NGUYEN

《结构与土木工程前沿（英文）》 2022年第16卷第7期页码 843-857 doi: 10.1007/s11709-022-0834-0

摘要： In this study, finite element (FE) analysis is utilized to investigate the shear capacity of reinforced concrete (RC) beams strengthened with embedded through-section (ETS) bars. Effects of critical variables on the beam shear strength, including the compressive strength of concrete, stiffness ratio between ETS bars and steel stirrups, and use of ETS strengthening system alone, are parametrically investigated. A promising method based on the bond mechanism between ETS strengthening and concrete is then proposed for predicting the shear resistance forces of the strengthened beams. An expression for the maximum bond stress of the ETS bars to concrete is developed. This new expression eliminates the difficulty in the search and selection of appropriate bond parameters from adhesion tests. The results obtained from the FE models and analytical models are validated by comparison with those measured from the experiments. Consequently, the model proposed in this study demonstrates better performance and more accuracy for prediction of the beam shear-carrying capacity than those of existing models. The results obtained from this study can also serve researchers and engineers in selection of the proper shear strength models for design of ETS-strengthened RC beams.

关键词： embedded through-section strengthening fiber-reinforced polymer finite element shear strength model bond mechanism

HTML PDF 收藏

STRENGTHENING NON-POINT SOURCE POLLUTION CONTROL TO PROMOTE AGRICULTURAL GREEN DEVELOPMENT

《农业科学与工程前沿（英文）》 2023年第10卷第4期页码 503-509 doi: 10.15302/J-FASE-2023528

摘要：

STRENGTHENING NON-POINT SOURCE POLLUTION CONTROL TO PROMOTE AGRICULTURAL GREEN DEVELOPMENT

关键词： GREEN AGRICULTURAL PROMOTE POLLUTION SOURCE DEVELOPMENT POINT STRENGTHENING CONTROL

HTML PDF 收藏

基于纳米铁碳析出物的钢综合强化机理

傅杰,李光强,于月光,毛新平,方克明

《中国工程科学》 2011年第13卷第1期页码 31-42

摘要：

简要叙述了关于钢强化机理的研究现状，用化学相分析+X射线小角散射、RTO方法及高分辨透射电镜对薄板坯连铸连轧钛微合金化高强耐候钢中纳米粒子的属性进行了综合分析。发现钛微合金化高强耐候钢中尺寸<36 nm的粒子，除纳米TiC以外，还存在大量的纳米Fe3C，其体积分数为同尺寸TiC体积分数的4.4倍，析出强化作用比纳米TiC粒子大，不可忽略；提出了钢的综合强化机理，指出对不同种类、不同尺寸的纳米析出粒子，应分别根据位错切割和位错绕过机理计算出析出强化贡献，然后与固溶强化和细晶强化贡献加和，求得钢的屈服强度；讨论了细晶强化与位错强化不能加和的原因以及相变对钢强度影响的表现形式，对钛微合金化高强耐候钢屈服强度的理论计算与生产结果相符，实验钢 σ_s= 630~676 MPa，实际 σ_s=630~680 MPa。简述了钢综合强化机理的应用情况，指出了有待进一步研究的科学问题。

关键词：屈服强度纳米铁碳析出物纳米TiC 析出强化钢的综合强化机理

HTML PDF 收藏

Experimental monitoring of the strengthening construction of a segmental box girder bridge and field

Ali Fadhil NASER, Zonglin WANG

《结构与土木工程前沿（英文）》 2012年第6卷第3期页码 308-320 doi: 10.1007/s11709-012-0140-3

摘要： Prestressed concrete segmental box girder bridges are composed of short concrete segments that are either precast or cast in situ and then joined together by longitudinally post-tensioning internal, external, or mixed tendons. The objectives of this study are to monitor the construction process of the external prestressing tendons to strengthen the bridge structure and perform a field load test to measure the strain and the deflection of the anchorage devices of the external prestressing tendons to determine the state of these devices after tension forces are applied. The monitoring process of the external prestressing tendons construction includes inspecting the cracks in the diaphragm anchorage and the deviation block devices before the tension forces are applied to the external tendons; measuring the deformation of the steel deviation cross beam during the tension process; measuring the deformation of the box girder after different levels of tension forces are applied; measuring the elongation of the external tendons in each level of the tension; and measuring the natural frequency of the external tendons after the tension process is complete. The results of the monitoring process show that the measured values of the deformation, the elongation, and the natural frequency meet the requirements. Therefore, there is no damage during the construction and the tensioning of the external prestressing tendons. A field load test is performed to the anchorage beam, the steel deviation block devices, and the steel deviation cross beam. The field load test results of the anchorage devices show that the values of the strains, the stresses, and the deflection are less than the respective allowable limit values in the requirements. Therefore, the anchorage devices have sufficient strength, and the working state is good after the tension forces are applied to the external prestressing tendons.

关键词： prestressed concrete box girder monitoring external tendons strain deflection

HTML PDF 收藏

Strengthening of the concrete face slabs of dams using sprayable strain-hardening fiber-reinforced cementitious

《结构与土木工程前沿（英文）》 2022年第16卷第2期页码 145-160 doi: 10.1007/s11709-022-0806-4

摘要： In this study, sprayable strain-hardening fiber-reinforced cementitious composites (FRCC) were applied to strengthen the concrete slabs in a concrete-face rockfill dam (CFRD) for the first time. Experimental, numerical, and analytical investigations were carried out to understand the flexural properties of FRCC-layered concrete slabs. It was found that the FRCC layer improved the flexural performance of concrete slabs significantly. The cracking and ultimate loads of a concrete slab with an 80 mm FRCC layer were 132% and 69% higher than those of the unstrengthened concrete slab, respectively. At the maximum crack width of 0.2 mm, the deflection of the 80-mm FRCC strengthened concrete slab was 144% higher than that of the unstrengthened concrete slab. In addition, a FE model and a simplified analytical method were developed for the design and analysis of FRCC-layered concrete slabs. Finally, the test result of FRCC leaching solution indicated that the quality of the water surrounding FRCC satisfied the standard for drinking water. The findings of this study indicate that the sprayable strain-hardening FRCC has a good potential for strengthening hydraulic structures such as CFRDs.

关键词： strain-hardening cementitious composites engineered cementitious composites sprayable shotcrete strengthening concrete-face rockfill dam digital image correlation

HTML PDF 收藏

预应力FRP加固工程结构技术研究进展

卢亦焱,陈娟,黄银燊,吴涛

《中国工程科学》 2008年第10卷第8期页码 40-44

摘要：

围绕国内外预应力FRP加固技术的研究现状以及最新进展，从预应力FRP加固混凝土结构、预应力FRP加固钢结构、预应力FRP加固中关键技术的研究等方面进行了综述。试验研究表明：预应力FRP加固混凝土能显著提高构件的开裂荷载、屈服荷载和极限荷载，改善受弯构件在长期荷载的力学性能，提高构件的疲劳寿命；预应力CFRP加固钢梁后，其屈服荷载和极限荷载相对于对比梁都有明显的提高，其提高的程度随着预应力CFRP的用量和预应力水平的提高而增大；预应力CFRP加固对钢梁的刚度提高作用也比较明显，对低强度的钢材，提高效果更明显；采用预应力FRP加固工程结构的关键问题在于预应力的施加体系、预应力控制值、预应力损失和端部的锚固。

关键词：纤维增强塑料加固技术混凝土结构钢结构研究进展

HTML PDF 收藏

Calculation of diagonal section and cross-section bending capacity for strengthening RC structure using

Shouping SHANG , Fangyuan ZHOU , Wei LIU ,

《结构与土木工程前沿（英文）》 2009年第3卷第3期页码 330-338 doi: 10.1007/s11709-009-0046-x

摘要： Because there is a great demand of reinforcement and retrofitting of aged structures nationwide, as well as the rapid development of innovative building materials, the adoption of strengthening RC structures using new inorganic materials has become possible. High-performance ferrocement laminate (HPFL) is an effective method of strengthening concrete structure. High-performance ferrocement laminate is a new type of inorganic material with the advantages such as high strength, small contraction, good bonding properties, etc. This paper introduces the formula of cross-section bending capacity for strengthening concrete beams with HPEL. A comparative analysis of experimental data, as well as the calculation of diagonal section bearing capacity of concrete members, is given.

关键词： RC beams high-performance ferrocement laminate (HPFL) inorganic material reinforcement

HTML PDF 收藏

薄板坯连铸连轧铁素体+珠光体类型钢的强化与软化

傅杰,吴华杰,刘阳春

《中国工程科学》 2008年第10卷第4期页码 65-72

摘要：

根据钢的综合强化理论，控制A1附近温度下钢中碳的析出，研究了HSLC钢的强化与软化问题。结果表明：薄板坯连铸连轧HSLC钢，强度还可进一步提高；通过回火缓冷，薄板坯连铸连轧HSLC钢ZJ330的σ_s从344 MPa降至225 MPa，能满足冷轧基板要求。讨论了有关铁素体轧制、超细晶粒钢以及一种可能的新型建筑材料等问题。

关键词： HSLC钢强化软化冷轧基板超级钢

HTML PDF 收藏

强化科技创新的中国林业科学研究院

《中国工程科学》 2001年第3卷第5期页码 92-93

HTML PDF 收藏

Molecular tailoring to improve polypyrrole hydrogels’ stiffness and electrochemical energy storage capacity

Evelyn Chalmers, Yi Li, Xuqing Liu

《化学科学与工程前沿（英文）》 2019年第13卷第4期页码 684-694 doi: 10.1007/s11705-019-1817-0

摘要： This research looks at ways of tailoring and improving the stiffness of polypyrrole hydrogels for use as flexible supercapacitor electrodes. Molecules providing additional cross-linking between polypyrrole chains are added post-polymerisation but before gelation, and are found to increase gel stiffness by up to 600%, with the degree of change dependent on reactant type and proportion. It was also found that addition of phytic acid led to an increase in pseudocapacitive behaviour of the hydrogel, and thus a maximum specific capacitance of 217.07 F·g could be achieved. This is an increase of 140% compared to pristine polypyrrole hydrogels produced by this method.

关键词： supercapacitor polypyrrole hydrogel strengthening electrochemical

HTML PDF 收藏

加强工程技术开发发展中国聚酯工业

蒋士成

《中国工程科学》 2001年第3卷第3期页码 27-33

摘要：

文章叙述了世界和亚洲聚酯及涤纶工业技术发展状况和趋势，并对市场、产能、产量等进行分析和预测。对中国聚酯及涤纶工业作了相应的分析和预测，寻找与国外的差距。介绍了国内聚酯工业工程技术开发的情况以及具体做法和成功的经验，并提出建议。

关键词：聚酯技术发展市场建议

HTML PDF 收藏

Investigation of the parameters affecting the behavior of RC beams strengthened with FRP

Kadir SENGUN; Guray ARSLAN

《结构与土木工程前沿（英文）》 2022年第16卷第6期页码 729-743 doi: 10.1007/s11709-022-0854-9

摘要： Three-point bending tests were carried out on nineteen Reinforced Concrete (RC) beams strengthened with FRP in the form of completely wrapping. The strip width to spacing ratios, FRP type, shear span to effective depth ratios, the number of FRP layers in shear, and the effect of stirrups spacing were the parameters investigated in the experimental study. The FRP contribution to strength on beams having the same strip width to spacing ratios could be affected by the shear span to effective depth ratios and stirrups spacing. The FRP contributions to strength were less on beams with stirrups in comparison to the tested beams without stirrups. Strengthening RC beams using FRP could change the failure modes of the beams compared to the reference beam. In addition to the experimental study, a number of equations used to predict the FRP contribution to the shear strength of the strengthened RC beams were assessed by using a limited number of beams available in the literature. The effective FRP strain is predicted by using test results, and this prediction is used to calculate the FRP contribution to shear strength in ACI 440.2R (2017) equation. Based on the statistical values of the data, the proposed equation has the lowest coefficient of variation (COV) value than the other equations.

关键词： carbon glass strengthening shear strength reinforced concrete beam fiber reinforced polymer