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期刊论文 18

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6016 铝合金 1

CFRP索斜拉桥 1

PBO纤维片材 1

力学性能 1

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增强加固 1

外粘结 1

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烘烤硬化性 1

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enhancement using carbon nanotubes on flexural behavior of RC beams strengthened with externally bonded CFRPsheets

《结构与土木工程前沿（英文）》 2022年 第16卷 第1期   页码 131-143 doi: 10.1007/s11709-021-0787-8

摘要： This paper studied the effect of incorporation of carbon nanotubes (CNTs) in carbon fiber reinforced polymer (CFRP) on strengthening of reinforced concrete (RC) beams. The RC beams were prepared, strengthened in flexure by externally bonded CFRP or CNTs-modified CFRP sheets, and tested under four-point loading. The experimental results showed the ability of the CNTs to delay the initiation of the cracks and to enhance the flexural capacity of the beams strengthened with CFRP. A nonlinear finite element (FE) model was built, validated, and used to study the effect of various parameters on the strengthening efficiency of CNTs-modified CFRP. The studied parameters included concrete strength, flexural reinforcement ratio, and CFRP sheet configuration. The numerical results showed that utilization of CNTs in CFRP production improved the flexural capacity of the strengthened beams for U-shape and underside-strip configurations. The enhancement was more pronounced in the case of U-shape than in the case of use of sheet strip covers on the underside of the beam. In case of using underside-strip, the longer or the wider the sheet, the higher was the flexural capacity of the beams. The flexural enhancement of RC beams by strengthening with CNTs-modified CFRP decreased with increasing the rebar diameter and was not affected by concrete strength.

关键词： RC beams     flexural     strengthening     CFRP     CNTs     finite element    

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Seismic retrofitting of severely damaged RC connections made with recycled concrete using CFRP sheets

Yasmin MURAD, Wassel AL BODOUR, Ahmed ASHTEYAT

《结构与土木工程前沿（英文）》 2020年 第14卷 第2期   页码 554-568 doi: 10.1007/s11709-020-0613-8

摘要： An experimental and numerical program is carried out in this research to investigate the influence of CFRP sheets on the cyclic behavior of unconfined connections made with recycled concrete. Cement is partially replaced by silica fume, iron filling and pulverised fuel ash using two different percentages: 15% and 20%. Each specimen is partially loaded at the first stage and then specimens are repaired using CFRP sheets. The repaired specimens are then laterally loaded until failure. In addition, a finite element model is built in ABAQUS and verified using the experimental results. The experimental results have shown that the repaired specimens have regained almost double the capacity of the un-repaired specimens and hence the adopted repair configuration is recommended for retrofitting seismically vulnerable RC connections. Increasing cement replacement percentage by silica fume, fuel ash or iron filling from 15% to 20% has reduced joint carrying capacity and weakened the joint. It is recommended using 15% pulverised fuel ash or silica fume as cement partial replacement to enhance the strength and ultimate drift of beam-column joints under cyclic loading. Iron filling concrete is also recommended but the enhancement is relatively less than that found with pulverised fuel ash concrete and silica fume concrete.

关键词： retrofitting     CFRP sheets     recycled concrete     pulverised fuel ash     silica fume     cyclic     beam-column connections    

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CFRP拉索预应力超高性能混凝土斜拉桥力学性能分析

方志,任亮,凡凤红

《中国工程科学》 2012年 第14卷 第7期   页码 53-59

摘要：

为了探讨碳纤维复合材料 (carbon fiber reinforced polymer, CFRP) 和超高性能活性粉末混凝土(reactivepowder concrete, RPC)在超大跨度斜拉桥中应用的可行性，以主跨1 008 m的大跨度钢主梁斜拉桥设计方案为例，采用拉索的等强度原则将原桥钢索替换成CFRP索，考虑截面刚度、截面应力和局部稳定等要求，将原桥钢主梁替换成RPC主梁，拟订了一座等跨度的CFRP拉索、RPC主梁斜拉桥方案。结果表明：从结构受力性能角度而言，采用超高性能混凝土主梁和CFRP拉索构成千米级跨度混凝土斜拉桥的结构体系是可行的。

关键词： 斜拉桥     碳纤维(CFRP)     活性粉末混凝土     力学性能    

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Axial compression behavior of CFRP-confined rectangular concrete-filled stainless steel tube stub column

《结构与土木工程前沿（英文）》 2021年 第15卷 第5期   页码 1144-1159 doi: 10.1007/s11709-021-0762-4

摘要： The mechanical properties of CFRP-confined rectangular concrete-filled stainless steel tube (CFSST) stub columns under axial compression were experimentally studied. A total of 28 specimens (7 groups) were fabricated for the axial compression test to study the influences of length-to-width ratio, CFRP constraint coefficient, and the thickness of stainless steel tube on the axial compression behavior. The specimen failure modes, the stress development of stainless steel tube and CFRP wrap, and the load–strain ratio curves in the loading process were obtained. Meanwhile, the relationship between axial and transverse deformations of each specimen was analyzed through the typical relative load−strain ratio curves. A bearing capacity prediction method was proposed based on the twin-shear strength theory, combining the limit equilibrium state of the CFRP-confined CFSST stub column under axial compression. The prediction method was calibrated by the test data in this study and other literature. The results show that the prediction method is of high accuracy.

关键词： CFRP     rectangular CFSST stub column     bearing capacity     limit equilibrium state     twin-shear strength theory    

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CFRP索斜拉桥动态特性的有限元分析及动态试验

蔡东升,刘荣桂,许飞,周士金

《中国工程科学》 2010年 第12卷 第2期   页码 16-21

摘要：

介绍了国内首座CFRP索斜拉桥的工程概况；建立了该桥的三维空间梁壳杆系有限元动态分析模型，进行了结构动态特性有限元分析；进行了环境激励下国内首座CFRP索斜拉桥结构动态特性的测试，结合试验结果对国内首座CFRP索斜拉桥的动态特性进行了分析。笔者等试验及相关研究分析结论可为CFRP索桥梁的动态建模、动态特性分析、抗震抗风设计及CFRP新型缆索材料在桥梁工程中的进一步推广应用提供一定的参考依据。

关键词： CFRP索斜拉桥     动态特性     有限元分析     环境激励     动态试验    

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Vibration analysis of nano-structure multilayered graphene sheets using modified strain gradient theory

Amir ALLAHBAKHSHI,Masih ALLAHBAKHSHI

《机械工程前沿（英文）》 2015年 第10卷 第2期   页码 187-197 doi: 10.1007/s11465-015-0339-9

摘要：

In this paper, for the first time, the modified strain gradient theory is used as a new size-dependent Kirchhoff micro-plate model to study the effect of interlayer van der Waals (vdW) force for the vibration analysis of multilayered graphene sheets (MLGSs). The model contains three material length scale parameters, which may effectively capture the size effect. The model can also degenerate into the modified couple stress plate model or the classical plate model, if two or all of the material length scale parameters are taken to be zero. After obtaining the governing equations based on modified strain gradient theory via principle of minimum potential energy, as only infinitesimal vibration is considered, the net pressure due to the vdW interaction is assumed to be linearly proportional to the deflection between two layers. To solve the governing equation subjected to the boundary conditions, the Fourier series is assumed for w=w(x, y). To show the accuracy of the formulations, present results in specific cases are compared with available results in literature and a good agreement can be seen. The results indicate that the present model can predict prominent natural frequency with the reduction of structural size, especially when the plate thickness is on the same order of the material length scale parameter.

关键词： graphene     van der Waals (vdW) force     modi- fied strain gradient elasticity theory     size effect parameter    

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Cooling performance of grid-sheets for highly loaded ultra-supercritical steam turbines

Dieter BOHN , Robert KREWINKEL , Shuqing TIAN ,

《能源前沿（英文）》 2009年 第3卷 第3期   页码 313-320 doi: 10.1007/s11708-009-0036-7

摘要： In order to increase efficiency and achieve a further CO-reduction, the next generation of power plant turbines will have steam turbine inlet temperatures that are considerably higher than the current ones. The high pressure steam turbine inlet temperature is expected to be increased up to approximately 700°C with a live steam pressure of 30MPa. The elevated steam parameters in the high and intermediate pressure turbines can be encountered with Ni-base alloys, but this is a costly alternative associated with many manufacturing difficulties. Collaborative research centre 561 “Thermally Highly Loaded, Porous and Cooled Multi-Layer Systems for Combined Cycle Power Plants” at RWTH Aachen University proposes cooling the highly loaded turbines instead, as this would necessitate the application of far less Ni-base alloys. To protect the thermally highly loaded components, a sandwich material consisting of two thin face sheets and a core made from a woven wire mesh is used to cover the walls of the steam turbine casing. The cooling steam is led through the woven wire mesh between the two face sheets to achieve a cooling effect. The wire mesh provides the grid-sheet with structural rigidity under varying operating conditions.In the present work, the cooling performance of the grid-sheets will be investigated applying the conjugate heat transfer method to ultra-supercritical live and cooling steam conditions for a section of the cooling structure. The behaviour of the flow and the heat transfer in the grid-sheet will be analyzed in detail using a parameter variation. The numerical results should give a first prediction of the cooling performance under future operating conditions.

关键词： steam turbines     700&     deg     C-technology     numerical inverstigation     cooling    

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Study of high-strength CFRP bolted joints with failure- monitoring cone washers

Tsukasa KATSUMATA, Yoshihiro MIZUTANI, Akira TODOROKI, Ryosuke MATSUZAKI

《机械工程前沿（英文）》 2011年 第6卷 第3期   页码 272-276 doi: 10.1007/s11465-011-0231-1

摘要：

To increase the strength of carbon-fiber-reinforced plastic (CFRP) bolted joints, a method to increase the friction force between carbon-fiber-reinforced plastic members was proposed. The increase in failure load for the proposed joint was confirmed in finite-element method analyses and joint tests. Additionally, the feasibility of damage monitoring using surface strains of the cone washer was demonstrated.

关键词： composite     bolted joint     failure monitoring     finite-element method    

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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    

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Studies of fiber-matrix debonding

Navneet DRONAMRAJU,Johannes SOLASS,Jörg HILDEBRAND

《结构与土木工程前沿（英文）》 2015年 第9卷 第4期   页码 448-456 doi: 10.1007/s11709-015-0316-8

摘要： In this paper, the debonding of a single fiber-matrix system of carbon fiber reinforced composite (CFRP) AS4/Epson 828 material is studied using Cohesive Zone Model (CZM). The effect of parameters namely, maximum tangential contact stress, tangential slip distance and artificial damping coefficient on the debonding length at the interface of the fiber-matrix is analyzed. Contact elements used in the CZM are coupled based on a bilinear stress-strain curve. Load is applied on the matrix, tangential to the interface. Hence, debonding is observed primarily in Mode II. Wide range of values are considered to study the inter-dependency of the parameters and its effect on debonding length. Out of the three parameters mentioned, artificial damping coefficient and tangential slip distance significantly affect debonding length. A thorough investigation is recommended for case wise interface debonding analysis, to estimate the optimal parametric values while using CZM.

关键词： single fibre     cohesive zone model     interface debonding     carbon fiber reinforced composite (CFRP)    

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Deflection behavior of a prestressed concrete beam reinforced with carbon fibers at elevated temperatures

Mohammed FARUQI, Mohammed Sheroz KHAN

《结构与土木工程前沿（英文）》 2019年 第13卷 第1期   页码 81-91 doi: 10.1007/s11709-018-0468-4

摘要： Fiber reinforced polymer(FRP) have unique advantages like high strength to weight ratio, excellent corrosion resistance, improving deformability and cost effectiveness. These advantages have gained wide acceptance in civil engineering applications. FRP tendons for prestressing applications are emerging as one of the most promising technologies in the civil engineering industry. However, the behavior of such members under the influence of elevated temperatures is still unknown. The knowledge and application of this could lead to a cost effective and practical considerations in fire safety design. Therefore, this study examines the deflection behavior of the carbon fiber reinforced polymer(CFRP) prestressed concrete beam at elevated temperatures. In this article, an analytical model is developed which integrates the temperature dependent changes of effective modulus of FRP in predicting the deflection behavior of CFRP prestressed concrete beams within the range of practical temperatures. This model is compared with a finite element mode (FEM) of a simply supported concrete beam prestressed with CFRP subjected to practical elevated temperatures. In addition, comparison is also made with an indirect reference to the real behavior of the material. The results of the model correlated reasonably with the finite element model and the real behavior. Finally, a practical application is provided.

关键词： FRP     CFRP     concrete     elevated temperatures     deflections     prestress    

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Prevention of laryngeal webs through endoscopic keel placement for bilateral vocal cord lesions

null

《医学前沿（英文）》 2018年 第12卷 第3期   页码 301-306 doi: 10.1007/s11684-017-0549-0

摘要：

Transoral microresection for treatment of vocal cord lesions involving the anterior commissure may result in anterior glottic webs. In this study, we retrospectively reviewed 54 patients who underwent microsurgery for bilateral lesions involving the anterior commissure and categorized them into two groups. The keel placement and control groups received endoscopic keel placement and mitomycin C, respectively. During the follow-up of at least 1 year, the laryngeal web formation rate significantly decreased in the keel placement group compared with that in the control group (18.6% versus 54.5%, <0.05). Furthermore, the voice handicap index-10 scores for patients without web formation decreased in both the keel placement and control groups ( <0.0001 and <0.001, respectively). A pseudomembrane covering the vocal cords was detected in 16.3% (7 of 43) cases after keel removal. A total of 100% (7 of 7) of these cases and 2.8% (1 of 36) of the other cases formed laryngeal webs ( <0.0001). Endoscopic keel placement could be an effective method for preventing anterior glottic webs after surgery for bilateral vocal cord diseases involving the anterior commissure. The pseudomembrane observed at the time of keel removal may imply a high risk of web formation.

关键词： glottic stenosis     glottic web     laryngeal keel     silastic sheets     anterior commissure    

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Multiscale model of micro curing residual stress evolution in carbon fiber-reinforced thermoset polymer composites

Xinyu HUI, Yingjie XU, Weihong ZHANG

《机械工程前沿（英文）》 2020年 第15卷 第3期   页码 475-483 doi: 10.1007/s11465-020-0590-6

摘要： In this study, the micro curing residual stresses of carbon fiber-reinforced thermoset polymer (CFRP) composites are evaluated using a multiscale modeling method. A thermochemical coupling model is developed at the macroscale level to obtain the distributions of temperature and degree of cure. Meanwhile, a representative volume element model of the composites is established at the microscale level. By introducing the information from the macroscale perspective, the curing residual stresses are calculated using the microscale model. The evolution of curing residual stresses reveals the interaction mechanism of fiber, matrix, and interphase period during the curing process. Results show that the curing residual stresses mostly present a tensile state in the matrix and a compressive state in the fiber. Furthermore, the curing residual stresses at different locations in the composites are calculated and discussed. Simulation results provide an important guideline for the analysis and design of CFRP composite structures.

关键词： CFRP     curing residual stress     multiscale modeling     finite element method    

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Experimental study on fire protection methods of reinforced concrete beams strengthened with carbon fiber reinforced polymer

HU Kexu, HE Guisheng, LU Fan

《结构与土木工程前沿（英文）》 2007年 第1卷 第4期   页码 399-404 doi: 10.1007/s11709-007-0054-7

摘要： In this paper, two reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymer (CFRP) and attached with thick-painted fire resistant coating were tested for fire resistance following the standard fire testing procedures. The experimental results show that the specimen pasted with the insulated layer of 50 mm in thickness could resist fire for 2.5 h. It is also demonstrated that the steel wire mesh embedded in the insulated layer can effectively prevent it from cracking and eroding under firing.

关键词： polymer     insulated     resistant     CFRP     resistance    

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PBO纤维片材预应力外粘结加固集成新技术

吴智深,岩下健太郎,牛赫东

《中国工程科学》 2005年 第7卷 第9期   页码 18-24

摘要：

近年采用外部粘结纤维增强复合材料(FRP)来加固结构越来越受到许多研究开发机构和生产单位的重视。结合作者在FRP方面的研究成果和最新开发出的高强高性能的PBO纤维材料，系统地提出了一种更为有效的预应力外粘结加固方法；通过与玻璃纤维、炭素纤维和芳纶纤维等的比较，认清了新型PBO纤维材料的特性；根据既有的试验和研究成果提出了一套完整的预应力加固方法的流程，包括概念、原理和几种降低端部界面应力和新型锚固的措施；室内小型试验和室外大型试验的结果表明，PBO片材预应力技术能够提供令人满意的加固性能。

关键词： 纤维增强聚合物(FRP)     PBO纤维片材     增强加固     外粘结     锚固措施    

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标题 作者 时间 类型 操作

enhancement using carbon nanotubes on flexural behavior of RC beams strengthened with externally bonded CFRPsheets

期刊论文

Seismic retrofitting of severely damaged RC connections made with recycled concrete using CFRP sheets

Yasmin MURAD, Wassel AL BODOUR, Ahmed ASHTEYAT

期刊论文

CFRP拉索预应力超高性能混凝土斜拉桥力学性能分析

方志,任亮,凡凤红

期刊论文

Axial compression behavior of CFRP-confined rectangular concrete-filled stainless steel tube stub column

期刊论文

CFRP索斜拉桥动态特性的有限元分析及动态试验

蔡东升,刘荣桂,许飞,周士金

期刊论文

Vibration analysis of nano-structure multilayered graphene sheets using modified strain gradient theory

Amir ALLAHBAKHSHI,Masih ALLAHBAKHSHI

期刊论文

Cooling performance of grid-sheets for highly loaded ultra-supercritical steam turbines

Dieter BOHN , Robert KREWINKEL , Shuqing TIAN ,

期刊论文

Study of high-strength CFRP bolted joints with failure- monitoring cone washers

Tsukasa KATSUMATA, Yoshihiro MIZUTANI, Akira TODOROKI, Ryosuke MATSUZAKI

期刊论文

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

Sheng PENG, Chengxiang XU, Xiaoqiang LIU

期刊论文

Studies of fiber-matrix debonding

Navneet DRONAMRAJU,Johannes SOLASS,Jörg HILDEBRAND

期刊论文

Deflection behavior of a prestressed concrete beam reinforced with carbon fibers at elevated temperatures

Mohammed FARUQI, Mohammed Sheroz KHAN

期刊论文

Prevention of laryngeal webs through endoscopic keel placement for bilateral vocal cord lesions

null

期刊论文

Multiscale model of micro curing residual stress evolution in carbon fiber-reinforced thermoset polymer composites

Xinyu HUI, Yingjie XU, Weihong ZHANG

期刊论文

Experimental study on fire protection methods of reinforced concrete beams strengthened with carbon fiber reinforced polymer

HU Kexu, HE Guisheng, LU Fan

期刊论文

PBO纤维片材预应力外粘结加固集成新技术

吴智深,岩下健太郎,牛赫东

期刊论文