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Development of deep neural network model to predict the compressive strength of FRCM confined columns

Khuong LE-NGUYEN; Quyen Cao MINH; Afaq AHMAD; Lanh Si HO

《结构与土木工程前沿(英文)》 2022年 第16卷 第10期   页码 1213-1232 doi: 10.1007/s11709-022-0880-7

摘要: The present study describes a reliability analysis of the strength model for predicting concrete columns confinement influence with Fabric-Reinforced Cementitious Matrix (FRCM). through both physical models and Deep Neural Network model (artificial neural network (ANN) with double and triple hidden layers). The database of 330 samples collected for the training model contains many important parameters, i.e., section type (circle or square), corner radius rc, unconfined concrete strength fco, thickness nt, the elastic modulus of fiber Ef , the elastic modulus of mortar Em. The results revealed that the proposed ANN models well predicted the compressive strength of FRCM with high prediction accuracy. The ANN model with double hidden layers (APDL-1) was shown to be the best to predict the compressive strength of FRCM confined columns compared with the ACI design code and five physical models. Furthermore, the results also reveal that the unconfined compressive strength of concrete, type of fiber mesh for FRCM, type of section, and the corner radius ratio, are the most significant input variables in the efficiency of FRCM confinement prediction. The performance of the proposed ANN models (including double and triple hidden layers) had high precision with R higher than 0.93 and RMSE smaller than 0.13, as compared with other models from the literature available.

关键词: FRCM     deep neural networks     confinement effect     strength model     confined concrete    

Micromechanics model for static and dynamic strength of concrete under confinement

ZHENG Dan

《结构与土木工程前沿(英文)》 2008年 第2卷 第4期   页码 329-335 doi: 10.1007/s11709-008-0044-4

摘要: The process of propagation, kinking of micro-cracks in concrete and the interaction among cracks as well as the induced failure were analyzed using the model that describes the wing type crack from the point of view of micromechanics. The pseudo-force method is applied to calculate the compressive strength factor of kinky propagated crack taking into account the effect of interaction among cracks. On the assumption that the micro fracture toughness of concrete does not vary with stain rate, the static and dynamic strength of concrete under different confinements can be calculated. The comparison of calculation result with experimental data indicates that a good agreement is achieved which implies that the model can be used to explain the rate-dependent properties of concrete in multi-axial stress state.

关键词: comparison     different     interaction     pseudo-force     toughness    

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    

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    

Finite element analysis of controlled low strength materials

Vahid ALIZADEH

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1243-1250 doi: 10.1007/s11709-019-0553-3

摘要: Controlled low strength materials (CLSM) are flowable and self-compacting construction materials that have been used in a wide variety of applications. This paper describes the numerical modeling of CLSM fills with finite element method under compression loading and the bond performance of CLSM and steel rebar under pullout loading. The study was conducted using a plastic-damage model which captures the material behavior using both classical theory of elasto-plasticity and continuum damage mechanics. The capability of the finite element approach for the analysis of CLSM fills was assessed by a comparison with the experimental results from a laboratory compression test on CLSM cylinders and pullout tests. The analysis shows that the behavior of a CLSM fill while subject to a failure compression load or pullout tension load can be simulated in a reasonably accurate manner.

关键词: CLSM     finite element method     compressive strength     pullout     numerical modeling     plastic damage model    

Shear-flexural strength mechanical model for the design and assessment of reinforced concrete beams subjected

Antonio MARÍ,Antoni CLADERA,Jesús BAIRÁN,Eva OLLER,Carlos RIBAS

《结构与土木工程前沿(英文)》 2014年 第8卷 第4期   页码 337-353 doi: 10.1007/s11709-014-0081-0

摘要: A mechanical model recently developed for the shear strength of slender reinforced concrete beams with and without shear reinforcement is presented and extended to elements with uniformly distributed loads, specially focusing on practical design and assessment in this paper. The shear strength is considered to be the sum of the shear transferred by the concrete compression chord, along the crack, due to residual tensile and frictional stresses, by the stirrups and, if they exist, by the longitudinal reinforcement. Based on the principles of structural mechanics simple expressions have been derived separately for each shear transfer action and for their interaction at ultimate limit state. The predictions of the model have been compared to those obtained by using the EC2, MC2010 and ACI 318-08 provisions and they fit very well the available experimental results from the recently published ACI-DAfStb databases of shear tests on slender reinforced concrete beams with and without stirrups. Finally, a detailed application example has been presented, obtaining each contributing component to the shear strength and the assumed shape and position of the critical crack.

关键词: shear strength     mechanical model     reinforced concrete     design     assessment     shear tests    

Data driven models for compressive strength prediction of concrete at high temperatures

Mahmood AKBARI, Vahid JAFARI DELIGANI

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 311-321 doi: 10.1007/s11709-019-0593-8

摘要: The use of data driven models has been shown to be useful for simulating complex engineering processes, when the only information available consists of the data of the process. In this study, four data-driven models, namely multiple linear regression, artificial neural network, adaptive neural fuzzy inference system, and nearest neighbor models based on collection of 207 laboratory tests, are investigated for compressive strength prediction of concrete at high temperature. In addition for each model, two different sets of input variables are examined: a complete set and a parsimonious set of involved variables. The results obtained are compared with each other and also to the equations of NIST Technical Note standard and demonstrate the suitability of using the data driven models to predict the compressive strength at high temperature. In addition, the results show employing the parsimonious set of input variables is sufficient for the data driven models to make satisfactory results.

关键词: data driven model     compressive strength     concrete     high temperature    

Determination of shear strength of steel fiber RC beams: application of data-intelligence models

Abeer A. AL-MUSAWI

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 667-673 doi: 10.1007/s11709-018-0504-4

摘要: Accurate prediction of shear strength of structural engineering components can yield a magnificent information modeling and predesign process. This paper aims to determine the shear strength of steel fiber reinforced concrete beams using the application of data-intelligence models namely hybrid artificial neural network integrated with particle swarm optimization. For the considered data-intelligence models, the input matrix attribute is one of the central element in attaining accurate predictive model. Hence, various input attributes are constructed to model the shear strength “as a targeted variable”. The modeling is initiated using historical published researches steel fiber reinforced concrete beams information. Seven variables are used as input attribute combination including reinforcement ratio ( ), concrete compressive strength ( ), fiber factor ( ), volume percentage of fiber ( ), fiber length to diameter ratio ( ) effective depth ( ), and shear span-to-strength ratio ( ), while the shear strength ( ) is the output of the matrix. The best network structure obtained using the network having ten nodes and one hidden layer. The final results obtained indicated that the hybrid predictive model of ANN-PSO can be used efficiently in the prediction of the shear strength of fiber reinforced concrete beams. In more representable details, the hybrid model attained the values of root mean square error and correlation coefficient 0.567 and 0.82, respectively.

关键词: hybrid intelligence model     shear strength     prediction     steel fiber reinforced concrete    

The influence of hand hole on the ultimate strength and crack pattern of shield tunnel segment jointsby scaled model test

Shaochun WANG, Xi JIANG, Yun BAI

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1200-1213 doi: 10.1007/s11709-019-0546-2

摘要: With the shield tunnel going deeper and deeper, the circumferential axial force becomes the governing factor rather than the bending moment. The hand hole acts as a weak point and initial damage in the segment joint especially when the circumferential axial force is extremely high. Despite the wide application of steel fiber or synthetic fiber in the tunneling, limited researches focus on the structural responses of segment joint with macro structural synthetic fiber (MSSF). In this paper, a 1:2 reduced-scale experiment was conducted to study the structural performance of the segment joint with different types of hand holes under ultra-high axial force. Special attention is paid to failure mode and structural performance (bearing capacity, deformation, cracking, and toughness). Moreover, segment joints with MSSF are also tested to evaluate the effects of MSSF on the failure mode and structural performance of the segment joints. The experiment results show that the hand hole becomes the weakest point of the segment joint under ultra-high axial force. A \ /-type crack pattern is always observed before the final failure of the segment joints. Different types and sizes of the hand hole have different degree of influences on the structural behavior of segment joints. The segment joint with MSSF shows higher ultimate bearing capacity and toughness compared to segment joint with common concrete. Besides, the MSSF improves the initial cracking load and anti-spallling resistance of the segment joint.

关键词: shield tunneling     structural synthetic fiber concrete     hand hole     segment joint     ultimate bearing capacity     crack pattern    

Evaluation of potential failure of rock slope at the left abutment of Jinsha River Bridge by model test

Zhiming ZHAO, Xihua WANG

《结构与土木工程前沿(英文)》 2013年 第7卷 第3期   页码 332-340 doi: 10.1007/s11709-013-0206-x

摘要: Jinsha River Bridge is located on Tiger Leaping Gorge town, China. The left bank slope composes of moderately thick layer of slate overlain by schistose basalt, and where rocks are controlled by two sets of joint planes. To evaluate the stability of the rock slope under bridge foundation, model test and calculation model based on the geological parameters and the slope stability was simulated and analyzed using Universal Distinct Element Code (UDEC) and Finite Element Mehod (FEM). According to model test, failure mainly initiated at the toe with shear movement along the joint planes, eventually resulting in the sliding along the slope surface and formation of tension crack at the crest of the model. This result coincide with the UDEC model, which shows that slope surface will produce loosening damage and slipping expected along the joint planes under different loading conditions. Moreover, the result of FEM analysis indicates that the rock mass under the main pier has potential shear failure region. So, the bridge foundation should be strengthened to prevent the slope failure under external forces.

关键词: slope stability     strength properties     model test     numerical analysis    

Predicting the capacity of perfobond rib shear connector using an ANN model and GSA method

Guorui SUN; Jun SHI; Yuang DENG

《结构与土木工程前沿(英文)》 2022年 第16卷 第10期   页码 1233-1248 doi: 10.1007/s11709-022-0878-1

摘要: Due to recent advances in the field of artificial neural networks (ANN) and the global sensitivity analysis (GSA) method, the application of these techniques in structural analysis has become feasible. A connector is an important part of a composite beam, and its shear strength can have a significant impact on structural design. In this paper, the shear performance of perfobond rib shear connectors (PRSCs) is predicted based on the back propagation (BP) ANN model, the Genetic Algorithm (GA) method and GSA method. A database was created using push-out test test and related references, where the input variables were based on different empirical formulas and the output variables were the corresponding shear strengths. The results predicted by the ANN models and empirical equations were compared, and the factors affecting shear strength were examined by the GSA method. The results show that the use of ANN model optimization by GA method has fewer errors compared to the empirical equations. Furthermore, penetrating reinforcement has the greatest sensitivity to shear performance, while the bonding force between steel plate and concrete has the least sensitivity to shear strength.

关键词: perfobond rib shear connector     shear strength     ANN model     global sensitivity analysis    

Endochronic damage constitutive model for fully-graded aggregate mass concrete

SONG Yupu, WANG Huailiang

《结构与土木工程前沿(英文)》 2007年 第1卷 第3期   页码 274-280 doi: 10.1007/s11709-007-0035-x

摘要: The behavior of deformation and strength of a fully-graded aggregate concrete under complex stress state is the basis of the nonlinear analysis and design for mass concrete structures such as concrete dams. In this paper, based on the combined endochronic theory with damage mechanics and on the quantities of experimental data, an endochronic damage constitutive model suitable for various aggregate grade concrete is proposed. This model takes into consideration the scale effect and the effect of wet screen sieve of aggregate in which the concept of yield surface is not needed and the difference of damage evolution rule of various graded aggregate concrete is a concern. The proposed model is used to analyze the deformation and strength of fully-graded aggregate mass concrete and the wet screened aggregate concrete specimens. The calculated results are in good agreement with experimental data, which can be used as a guide for the design of arch dams and other mass concrete structures.

关键词: concept     surface     design     concern     strength    

基于人工神经网络的多处损伤加筋板剩余强度预测

杨茂胜,陈跃良,郁大照

《中国工程科学》 2008年 第10卷 第5期   页码 46-50

摘要:

用BP神经网络算法对多处损伤加筋板的剩余强度数据进行训练学习,将预测值和3种经典分析方法的计算值与实验值进行对比,结果表明,ANN法预测值与实验值吻合得最好,LMC修正法和WSU3修正法次之,Swift塑性区连通法最差。最后用所建立的BP网络对不同主裂纹半长和韧带长度的剩余强度进行了预测,结果发现,在其他参数不变的情况下,不管是双筋条还是三筋条加筋板,剩余强度总是随主裂纹半长的增加而成线性降低,随韧带长度的增加而成线性增加,但双筋条加筋板比三筋条加筋板对主裂纹半长和韧带长度的变化更加敏感。

关键词: 神经网络     多处损伤     加筋板     剩余强度    

Cyclic stress-strain behavior of structural steel with yield-strength up to 460 N/mm

Yiyi CHEN,Wei SUN,Tak-Ming CHAN

《结构与土木工程前沿(英文)》 2014年 第8卷 第2期   页码 178-186 doi: 10.1007/s11709-014-0245-y

摘要: This paper presents a constitutive model based on Ramberg-Osgood equation to describe the hysteresis material behavior of structural carbon steel with nominal yield strength between 235 to 420 N/mm . The proposed model was calibrated against a series of cyclic material tests with strain amplitude varying from 0.5% to 2.0%. A simple relationship between the modular parameter and the yield strength was proposed. The calibrated Ramberg-Osgood model revealed excellent agreement with the experimental results and captured further the experimental behavior of test specimens with nominal yield strength of 460 N/mm . The proposed constitutive model was also adopted in conjunction with the combined kinematic/isotropic materials description in ABAQUS to mimic a full scale experimental test under cyclic loading. The numerical results revealed close agreement with the experimental observations.

关键词: constitutive model     finite element analysis     hysteresis curve     Ramberg-Osgood equation    

国产环氧沥青混合料固化强度增长规律研究

钱振东,王亚奇,沈家林

《中国工程科学》 2012年 第14卷 第5期   页码 90-95

摘要:

研究了环氧沥青混合料的强度形成机理,在此基础上对影响环氧沥青混合料强度的两个重要因素即混合料的容留时间、养生温度进行了研究,确定了不同温度下环氧沥青混合料的容留时间范围及强度增长规律;采用差示扫描量热法(DSC)测得环氧沥青结合料在不同升温速率下的动态DSC曲线,通过非线性回归求得固化动力学关键参数,建立环氧沥青结合料的固化反应模型。研究结果可以指导环氧沥青混合料的生产与施工,同时对铺装层开放交通时间的确定有参考意义。

关键词: 环氧沥青     强度增长     时温条件     固化反应模型    

标题 作者 时间 类型 操作

Development of deep neural network model to predict the compressive strength of FRCM confined columns

Khuong LE-NGUYEN; Quyen Cao MINH; Afaq AHMAD; Lanh Si HO

期刊论文

Micromechanics model for static and dynamic strength of concrete under confinement

ZHENG Dan

期刊论文

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

Linh Van Hong BUI; Phuoc Trong NGUYEN

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

Finite element analysis of controlled low strength materials

Vahid ALIZADEH

期刊论文

Shear-flexural strength mechanical model for the design and assessment of reinforced concrete beams subjected

Antonio MARÍ,Antoni CLADERA,Jesús BAIRÁN,Eva OLLER,Carlos RIBAS

期刊论文

Data driven models for compressive strength prediction of concrete at high temperatures

Mahmood AKBARI, Vahid JAFARI DELIGANI

期刊论文

Determination of shear strength of steel fiber RC beams: application of data-intelligence models

Abeer A. AL-MUSAWI

期刊论文

The influence of hand hole on the ultimate strength and crack pattern of shield tunnel segment jointsby scaled model test

Shaochun WANG, Xi JIANG, Yun BAI

期刊论文

Evaluation of potential failure of rock slope at the left abutment of Jinsha River Bridge by model test

Zhiming ZHAO, Xihua WANG

期刊论文

Predicting the capacity of perfobond rib shear connector using an ANN model and GSA method

Guorui SUN; Jun SHI; Yuang DENG

期刊论文

Endochronic damage constitutive model for fully-graded aggregate mass concrete

SONG Yupu, WANG Huailiang

期刊论文

基于人工神经网络的多处损伤加筋板剩余强度预测

杨茂胜,陈跃良,郁大照

期刊论文

Cyclic stress-strain behavior of structural steel with yield-strength up to 460 N/mm

Yiyi CHEN,Wei SUN,Tak-Ming CHAN

期刊论文

国产环氧沥青混合料固化强度增长规律研究

钱振东,王亚奇,沈家林

期刊论文