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An enhanced damage plasticity model for predicting the cyclic behavior of plain concrete under multiaxial

Mohammad Reza AZADI KAKAVAND, Ertugrul TACIROGLU

《结构与土木工程前沿(英文)》 2020年 第14卷 第6期   页码 1531-1544 doi: 10.1007/s11709-020-0675-7

摘要: Some of the current concrete damage plasticity models in the literature employ a single damage variable for both the tension and compression regimes, while a few more advanced models employ two damage variables. Models with a single variable have an inherent difficulty in accounting for the damage accrued due to tensile and compressive actions in appropriately different manners, and their mutual dependencies. In the current models that adopt two damage variables, the independence of these damage variables during cyclic loading results in the failure to capture the effects of tensile damage on the compressive behavior of concrete and vice-versa. This study presents a cyclic model established by extending an existing monotonic constitutive model. The model describes the cyclic behavior of concrete under multiaxial loading conditions and considers the influence of tensile/compressive damage on the compressive/tensile response. The proposed model, dubbed the enhanced concrete damage plasticity model (ECDPM), is an extension of an existing model that combines the theories of classical plasticity and continuum damage mechanics. Unlike most prior studies on models in the same category, the performance of the proposed ECDPM is evaluated using experimental data on concrete specimens at the material level obtained under cyclic multiaxial loading conditions including uniaxial tension and confined compression. The performance of the model is observed to be satisfactory. Furthermore, the superiority of ECDPM over three previously proposed constitutive models is demonstrated through comparisons with the results of a uniaxial tension-compression test and a virtual test.

关键词: damage plasticity model     plain concrete     cyclic loading     multiaxial loading conditions    

Damage-constitutive model for seawater coral concrete using different stirrup confinements subjected

《结构与土木工程前沿(英文)》 2023年 第17卷 第3期   页码 429-447 doi: 10.1007/s11709-022-0913-2

摘要: Recently, the application of detrital coral as an alternative to natural aggregates in marine structures has attracted increased attention. In this study, research on the compressive performance of coral aggregate concrete (CAC) confined using steel stirrups with anti-rust treatment was experimentally conducted. A total of 45 specimens were cast, including 9 specimens without stirrups and under different strength grades (C20, C30, and C40) and 36 specimens under different strength grades (C20, C30, and C40). Moreover, three stirrup levels (rectangular, diamond-shaped compound, and spiral stirrups) and different stirrup spacings (40, 50, 60, and 70 mm) were used. Subsequently, the stress−strain curves of specimens subjected to axial loading were measured. The effects of the stirrup spacing and stirrup configurations on the stress and strain were investigated, respectively, and the lateral effective stress of the different stirrups was calculated based on the cohesive-elastic ring model and modified elastic beam theory. Moreover, a damage-constitutive model of CAC considering the lateral stress was set up based on damage mechanics theory. The results indicated an increase in the stress and strain with a decrease in the stirrup spacing, and the adopted stirrup ratio had a better strengthening effect than the different concrete grades, and the variation in the deformation was restricted by the performance of coral coarse aggregate (CA). However, an increment in the lateral strain was observed with an increase in the axial strain. The lateral stress model showed a good agreement with the experimental data, and the proposed damage-constitutive model had a good correlation with the measured stress−strain curves.

关键词: coral aggregate concrete     stress−strain curves     lateral effective stress     peak stress     axial−lateral curves     damage-constitutive model.    

Uncertainty quantification of stability and damage detection parameters of coupled hydrodynamic-groundmotion in concrete gravity dams

Nazim Abdul NARIMAN, Tom LAHMER, Peyman KARAMPOUR

《结构与土木工程前沿(英文)》 2019年 第13卷 第2期   页码 303-323 doi: 10.1007/s11709-018-0462-x

摘要: In this paper, models of the global system of the Koyna dam have been created using ABAQUS software considering the dam-reservoir-foundation interaction. Non coupled models and the coupled models were compared regarding the horizontal displacement of the dam crest and the differential settlement of the dam base in clay foundation. Meta models were constructed and uncertainty quantification process was adopted by the support of Sobol’s sensitivity indices considering five uncertain parameters by exploiting Box-Behnken experimental method. The non coupled models results determined overestimated predicted stability and damage detection in the dam. The rational effects of the reservoir height were very sensitive in the variation of the horizontal displacement of the dam crest with a small interaction effect with the beta viscous damping coefficient of the clay foundation. The modulus of elasticity of the clay foundation was the decisive parameter regarding the variation of the differential settlement of the dam base. The XFEM approach has been used for damage detection in relation with both minimum and maximum values of each uncertain parameter. Finally the effects of clay and rock foundations were determined regarding the resistance against the propagation of cracks in the dam, where the rock foundation was the best.

关键词: massed foundation     hydrodynamic pressure     Box-Behnken method     meta model     Sobol’s sensitivity indices    

Cyclic behavior of prefabricated reinforced concrete frame with infill slit shear walls

Kui XIAO,Qilin ZHANG,Bin JIA

《结构与土木工程前沿(英文)》 2016年 第10卷 第1期   页码 63-71 doi: 10.1007/s11709-015-0294-x

摘要: A composite structural system consisting of prefabricated reinforced concrete frame with infill slit shear walls (PRCFW), with good ductility, is a new type of earthquake resistant structure. Pseudo-static tests were performed to evaluate the seismic behavior of the PRCFW system. Two one-bay, two-story PRCFW specimens were both built at one-half scale. Additional computational research is also conducted to enhance the nonlinear analytical capabilities for this system. Combined with the concrete damaged plastic (CDP) model provided by finite element program ABAQUS and the constitutive model of concrete proposed by Chinese code, the damage process of the PRCFW structure under cyclic load is simulated. The simulated results show a good agreement with the test data, the dynamic behavior of the PRCFW system can be simulated sufficiently accurate and efficient to provide useful design information. The experimental and numerical study show that this system has the potential to offer good ductility and energy absorption capacity to dissipate input energy, and stiffness adequate for controlling drift for buildings located in earthquake-prone regions.

关键词: slit shear wall     constitutive model     cyclic     seismic     damage    

Dynamic failure analysis of concrete dams under air blast using coupled Euler-Lagrange finite element

Farhoud KALATEH

《结构与土木工程前沿(英文)》 2019年 第13卷 第1期   页码 15-37 doi: 10.1007/s11709-018-0465-7

摘要: In this study, the air blast response of the concrete dams including dam-reservoir interaction and acoustic cavitation in the reservoir is investigated. The finite element (FE) developed code are used to build three-dimensional (3D) finite element models of concrete dams. A fully coupled Euler-Lagrange formulation has been adopted herein. A previous developed model including the strain rate effects is employed to model the concrete material behavior subjected to blast loading. In addition, a one-fluid cavitating model is employed for the simulation of acoustic cavitation in the fluid domain. A parametric study is conducted to evaluate the effects of the air blast loading on the response of concrete dam systems. Hence, the analyses are performed for different heights of dam and different values of the charge distance from the charge center. Numerical results revealed that 1) concrete arch dams are more vulnerable to air blast loading than concrete gravity dams; 2) reservoir has mitigation effect on the response of concrete dams; 3) acoustic cavitation intensify crest displacement of concrete dams.

关键词: air blast loading     concrete dams     finite element     dam-reservoir interaction     cavitation     concrete damage model    

The damage evolution behavior of polypropylene fiber reinforced concrete subjected to sulfate attack

Ninghui LIANG; Jinwang MAO; Ru YAN; Xinrong LIU; Xiaohan ZHOU

《结构与土木工程前沿(英文)》 2022年 第16卷 第3期   页码 316-328 doi: 10.1007/s11709-022-0810-8

摘要: To study the damage evolution behavior of polypropylene fiber reinforced concrete (PFRC) subjected to sulfate attack, a uniaxial compression test was carried out based on acoustic emission (AE). The effect of sulfate attack relative to time and fiber hybridization were analyzed and the compression damage factor was calculated using a mathematical model. The changes to AE ringing counts during the compression could be divided into compaction, elastic, and AE signal hyperactivity stages. In the initial stage of sulfate attack, the concrete micropores and microcracks were compacted gradually under external load and a corrosion products filling effect, and this corresponded with detection of few AE signals and with concrete compression strength enhancement. With increasing sulfate attack time, AE activity decreased. The cumulative AE ringing counts of PFRC at all corrosion ages were much higher than those for plain concrete. PFRC could still produce AE signals after peak load due to drawing effect of polypropylene fiber. After 150 d of sulfate attack, the cumulative AE ringing counts of plain concrete went down by about an order of magnitude, while that for PFRC remained at a high level. The initial damage factor of hybrid PFRC was −0.042 and −0.056 respectively after 150 d of corrosion, indicating that the advantage of hybrid polypropylene fiber was more obvious than plain concrete and single-doped PFRC. Based on a deterioration equation, the corrosion resistance coefficient of hybrid PFRC would be less than 0.75 after 42 drying−wetting sulfate attack cycles, which was 40% longer than that of plain concrete.

关键词: polypropylene fiber reinforced concrete     sulfate attack     damage evolution behavior     acoustic emission     damage factor    

Influence of construction-induced damage on the degradation of freeze–thawed lightweight cellular concrete

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 781-792 doi: 10.1007/s11709-021-0733-9

摘要: During the construction of lightweight cellular concrete (LCC), material damage frequently occurs, causing the degradation and deterioration of the mechanical performance, durability, and subgrade quality of LCC. The construction-induced damage can be more significant than those from the service environment of LCC, such as freeze–thaw (F–T) action in cold regions. However, the effect of construction-induced damage on LCC during F–T cycles is often ignored and the deterioration mechanisms are not yet clarified. In this study, we investigated the factors causing damage during construction using a sample preparation method established to simulate the damage in the laboratory setting. We conducted F–T cycle tests and microstructural characterization to study the effect of microstructural damage on the overall strength of LCC with different water contents under F–T actions. We established the relationship between the pore-area ratio and F–T cycle times, pore-area ratio, and strength, as well as the F–T cycle times and strength under different damage forms. The damage evolution is provided with the rationality of the damage equation, verified by comparing the measured and predicted damage variables. This study would serve as a guide for the construction and performance of LCC in cold regions.

关键词: lightweight cellular concrete     construction-induced damage     freeze-thaw action     microstructure     degradation mechanism    

Influence of freeze–thaw damage gradient on stress–strain relationship of stressed concrete

《结构与土木工程前沿(英文)》 2023年 第17卷 第9期   页码 1326-1340 doi: 10.1007/s11709-023-0014-x

摘要: Influence of freeze–thaw damage gradient on stress–strain relationship of stressed concrete

关键词: strain relationship concrete    

Damage assessment and diagnosis of hydraulic concrete structures using optimization-based machine learning

《结构与土木工程前沿(英文)》 2023年 第17卷 第8期   页码 1281-1294 doi: 10.1007/s11709-023-0975-9

摘要: Concrete is widely used in various large construction projects owing to its high durability, compressive strength, and plasticity. However, the tensile strength of concrete is low, and concrete cracks easily. Changes in the concrete structure will result in changes in parameters such as the frequency mode and curvature mode, which allows one to effectively locate and evaluate structural damages. In this study, the characteristics of the curvature modes in concrete structures are analyzed and a method to obtain the curvature modes based on the strain and displacement modes is proposed. Subsequently, various indices for the damage diagnosis of concrete structures based on the curvature mode are introduced. A damage assessment method for concrete structures is established using an artificial bee colony backpropagation neural network algorithm. The proposed damage assessment method for dam concrete structures comprises various modal parameters, such as curvature and frequency. The feasibility and accuracy of the model are evaluated based on a case study of a concrete gravity dam. The results show that the damage assessment model can accurately evaluate the damage degree of concrete structures with a maximum error of less than 2%, which is within the required accuracy range of damage identification and assessment for most concrete structures.

关键词: hydraulic structure     curvature mode     damage detection     artifical neural network     artificial bee colony    

Effect of seismic wave propagation in massed medium on rate-dependent anisotropic damage growth in concrete

Alireza DANESHYAR, Hamid MOHAMMADNEZHAD, Mohsen GHAEMIAN

《结构与土木工程前沿(英文)》 2021年 第15卷 第2期   页码 346-363 doi: 10.1007/s11709-021-0694-z

摘要: Seismic modeling of massive structures requires special caution, as wave propagation effects significantly affect the responses. This becomes more crucial when the path-dependent behavior of the material is considered. The coexistence of these conditions renders numerical earthquake analysis of concrete dams challenging. Herein, a finite element model for a comprehensive nonlinear seismic simulation of concrete gravity dams, including realistic soil–structure interactions, is introduced. A semi-infinite medium is formulated based on the domain reduction method in conjunction with standard viscous boundaries. Accurate representation of radiation damping in a half-space medium and wave propagation effects in a massed foundation are verified using an analytical solution of vertically propagating shear waves in a viscoelastic half-space domain. A rigorous nonlinear finite element model requires a precise description of the material response. Hence, a microplane-based anisotropic damage–plastic model of concrete is formulated to reproduce irreversible deformations and tensorial degeneration of concrete in a coupled and rate-dependent manner. Finally, the Koyna concrete gravity dam is analyzed based on different assumptions of foundation, concrete response, and reservoir conditions. Comparison between responses obtained based on conventional assumptions with the results of the presented comprehensive model indicates the significance of considering radiation damping and employing a rigorous constitutive material model, which is pursued for the presented model.

关键词: soil–structure interaction     massed foundation     radiation damping     anisotropic damage    

A cumulative damage model for predicting and assessing raveling in asphalt pavement using an energy dissipation

《结构与土木工程前沿(英文)》 2024年 第18卷 第6期   页码 949-962 doi: 10.1007/s11709-024-1074-2

摘要: Raveling is a common distress of asphalt pavements, defined as the removal of stones from the pavement surface. To predict and assess raveling quantitatively, a cumulative damage model based on an energy dissipation approach has been developed at the meso level. To construct the model, a new test method, the pendulum impact test, was employed to determine the fracture energy of the stone-mastic-stone meso-unit, while digital image analysis and dynamic shear rheometer test were used to acquire the strain rate of specimens and the rheology property of mastic, respectively. Analysis of the model reveals that when the material properties remain constant, the cumulative damage is directly correlated with loading time, loading amplitude, and loading frequency. Specifically, damage increases with superimposed linear and cosine variations over time. A higher stress amplitude results in a more rapidly increasing rate of damage, while a lower load frequency leads to more severe damage within the same loading time. Moreover, an example of the application of the model has been presented, showing that the model can be utilized to estimate failure life due to raveling. The model is able to offer a theoretical foundation for the design and maintenance of anti-raveling asphalt pavements.

关键词: asphalt pavement     raveling     cumulative damage     dissipation energy theory    

Crack identification in concrete, using digital image correlation and neural network

《结构与土木工程前沿(英文)》 2024年 第18卷 第4期   页码 536-550 doi: 10.1007/s11709-024-1013-2

摘要: In engineering applications, concrete crack monitoring is very important. Traditional methods are of low efficiency, low accuracy, have poor timeliness, and are applicable in only a limited number of scenarios. Therefore, more comprehensive detection of concrete damage under different scenarios is of high value for practical engineering applications. Digital image correlation (DIC) technology can provide a large amount of experimental data, and neural network (NN) can process very rich data. Therefore, NN, including convolutional neural networks (CNN) and back propagation neural networks (BP), can be combined with DIC technology to analyze experimental data of three-point bending of plain concrete and four-point bending of reinforced concrete. In addition, strain parameters can be used for training, and displacement parameters can be added for comprehensive consideration. The data obtained by DIC technology are grouped for training, and the recognition results of NN show that the combination of strain and displacement parameters, i.e., the response of specimen surface and whole body, can make results more objective and comprehensive. The identification results obtained by CNN and BP show that these technologies can accurately identify cracks. The identification results for reinforced concrete specimens are less affected by noise than those of plain concrete specimens. CNN is more convenient because it can identify some features directly from images, recognizing the cracks formed by macro development. BP can issue early warning of the microscopic cracks, but it requires a large amount of data and computation. It can be seen that CNN is more intuitive and efficient in image processing, and is suitable when low accuracy is adequate, while BP is suitable for occasions with greater accuracy requirements. The two tools have advantages in different situations, and together they can play an important role in engineering monitoring.

关键词: digital image correlation     convolutional neural network     back propagation neural neural network     damage detection     concrete    

Investigation on the freeze-thaw damage to the jointed plain concrete pavement under different climate

Shuaicheng GUO, Qingli DAI, Jacob HILLER

《结构与土木工程前沿(英文)》 2018年 第12卷 第2期   页码 227-238 doi: 10.1007/s11709-017-0426-6

摘要: Freeze-thaw damage is one of the main threats to the long time performance of the concrete pavement in the cold regions. This project aims to evaluate the influence of the freeze-thaw damages on pavement distresses under different climate conditions. Based on the Long-Term Pavement Performance (LTPP) data base, the freeze-thaw damage generated by four different kinds of climate conditions are considered in this project: wet-freeze, wet-non freeze, dry-freeze and dry-non freeze. The amount of the transverse crack and the joint spalling, along with the International Roughness Index ( ) are compared among the test sections located in these four different climate conditions. The back calculation with the Falling Weight Deflectometer (FWD) test results based on the ERES and the Estimation of Concrete Pavement Parameters (ECOPP) methods are conducted to obtain concrete slab elastic modulus and the subgrade -value. These two parameters both decrease with service time under freeze condition. Finally, MEPDG simulation is conducted to simulate the development with service year. These results showed the reasonable freeze-thaw damage development with pavement service life and under different climate conditions.

关键词: LTPP     elastic modulus     k-value     IRI     MEPDG    

面向健康诊断的混凝土斜拉桥模型设计与分析

张国刚,方志,唐盛华,陈素君,陈峰

《中国工程科学》 2012年 第14卷 第11期   页码 49-56

摘要:

以广东惠州合生大桥为原型,基于相似理论面向健康诊断设计制作了1∶15的大比例混凝土斜拉桥模型,分析了模型设计中的问题及解决办法。建立了原型桥和模型桥的初始有限元模型(FEM),以实测数据对其进行修正,得到了符合实际的基准有限元模型,采用基准有限元模型对模型桥和原型桥的静动力特性及损伤状态下的损伤特性进行了计算和相似性分析。结果表明,模型设计中进行了各种简化和处理后,模型桥与原型桥的静动力性能及损伤状态下的损伤特性仍具有良好的相似性,采用该模型桥进行损伤识别试验研究能够较好地反映实际,为混凝土斜拉桥模型设计提供参考。

关键词: 混凝土斜拉桥     模型设计     模型修正     损伤诊断    

A deep neural network based surrogate model for damage identification in full-scale structures with incomplete

《结构与土木工程前沿(英文)》 2024年 第18卷 第3期   页码 393-410 doi: 10.1007/s11709-024-1060-8

摘要: The paper introduces a novel approach for detecting structural damage in full-scale structures using surrogate models generated from incomplete modal data and deep neural networks (DNNs). A significant challenge in this field is the limited availability of measurement data for full-scale structures, which is addressed in this paper by generating data sets using a reduced finite element (FE) model constructed by SAP2000 software and the MATLAB programming loop. The surrogate models are trained using response data obtained from the monitored structure through a limited number of measurement devices. The proposed approach involves training a single surrogate model that can quickly predict the location and severity of damage for all potential scenarios. To achieve the most generalized surrogate model, the study explores different types of layers and hyperparameters of the training algorithm and employs state-of-the-art techniques to avoid overfitting and to accelerate the training process. The approach’s effectiveness, efficiency, and applicability are demonstrated by two numerical examples. The study also verifies the robustness of the proposed approach on data sets with sparse and noisy measured data. Overall, the proposed approach is a promising alternative to traditional approaches that rely on FE model updating and optimization algorithms, which can be computationally intensive. This approach also shows potential for broader applications in structural damage detection.

关键词: vibration-based damage detection     deep neural network     full-scale structures     finite element model updating     noisy incomplete modal data    

标题 作者 时间 类型 操作

An enhanced damage plasticity model for predicting the cyclic behavior of plain concrete under multiaxial

Mohammad Reza AZADI KAKAVAND, Ertugrul TACIROGLU

期刊论文

Damage-constitutive model for seawater coral concrete using different stirrup confinements subjected

期刊论文

Uncertainty quantification of stability and damage detection parameters of coupled hydrodynamic-groundmotion in concrete gravity dams

Nazim Abdul NARIMAN, Tom LAHMER, Peyman KARAMPOUR

期刊论文

Cyclic behavior of prefabricated reinforced concrete frame with infill slit shear walls

Kui XIAO,Qilin ZHANG,Bin JIA

期刊论文

Dynamic failure analysis of concrete dams under air blast using coupled Euler-Lagrange finite element

Farhoud KALATEH

期刊论文

The damage evolution behavior of polypropylene fiber reinforced concrete subjected to sulfate attack

Ninghui LIANG; Jinwang MAO; Ru YAN; Xinrong LIU; Xiaohan ZHOU

期刊论文

Influence of construction-induced damage on the degradation of freeze–thawed lightweight cellular concrete

期刊论文

Influence of freeze–thaw damage gradient on stress–strain relationship of stressed concrete

期刊论文

Damage assessment and diagnosis of hydraulic concrete structures using optimization-based machine learning

期刊论文

Effect of seismic wave propagation in massed medium on rate-dependent anisotropic damage growth in concrete

Alireza DANESHYAR, Hamid MOHAMMADNEZHAD, Mohsen GHAEMIAN

期刊论文

A cumulative damage model for predicting and assessing raveling in asphalt pavement using an energy dissipation

期刊论文

Crack identification in concrete, using digital image correlation and neural network

期刊论文

Investigation on the freeze-thaw damage to the jointed plain concrete pavement under different climate

Shuaicheng GUO, Qingli DAI, Jacob HILLER

期刊论文

面向健康诊断的混凝土斜拉桥模型设计与分析

张国刚,方志,唐盛华,陈素君,陈峰

期刊论文

A deep neural network based surrogate model for damage identification in full-scale structures with incomplete

期刊论文