Computers and Concrete最新文献_第5页

Modeling concrete fracturing using a hybrid finite-discrete element method 用混合有限-离散元法模拟混凝土断裂

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-04-01 DOI: 10.12989/CAC.2021.27.4.297

D. Elmo, A. Mitelman

引用次数: 3

Bond strength prediction of spliced GFRP bars in concrete beams using soft computing methods 用软计算方法预测GFRP筋在混凝土梁中的粘结强度

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-04-01 DOI: 10.12989/CAC.2021.27.4.305

S. F. Shahri, S. Mousavi

{"title":"Bond strength prediction of spliced GFRP bars in concrete beams using soft computing methods","authors":"S. F. Shahri, S. Mousavi","doi":"10.12989/CAC.2021.27.4.305","DOIUrl":"https://doi.org/10.12989/CAC.2021.27.4.305","url":null,"abstract":"The bond between the concrete and bar is a main factor affecting the performance of the reinforced concrete (RC) members, and since the steel corrosion reduces the bond strength, studying the bond behavior of concrete and GFRP bars is quite necessary. In this research, a database including 112 concrete beam test specimens reinforced with spliced GFRP bars in the splitting failure mode has been collected and used to estimate the concrete-GFRP bar bond strength. This paper aims to accurately estimate the bond strength of spliced GFRP bars in concrete beams by applying three soft computing models including multivariate adaptive regression spline (MARS), Kriging, and M5 model tree. Since the selection of regularization parameters greatly affects the fitting of MARS, Kriging, and M5 models, the regularization parameters have been so optimized as to maximize the training data convergence coefficient. Three hybrid model coupling soft computing methods and genetic algorithm is proposed to automatically perform the trial and error process for finding appropriate modeling regularization parameters. Results have shown that proposed models have significantly increased the prediction accuracy compared to previous models. The proposed MARS, Kriging, and M5 models have improved the convergence coefficient by about 65, 63 and 49%, respectively, compared to the best previous model.","PeriodicalId":50625,"journal":{"name":"Computers and Concrete","volume":"123 1","pages":"305-317"},"PeriodicalIF":4.1,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77434116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Computer simulation for stability analysis of the viscoelastic annular plate with reinforced concrete face sheets 钢筋混凝土面板粘弹性环形板稳定性的计算机模拟分析

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-04-01 DOI: 10.12989/CAC.2021.27.4.369

Yonggang Zhang, Yonghong Wang, Y. Zhao

{"title":"Computer simulation for stability analysis of the viscoelastic annular plate with reinforced concrete face sheets","authors":"Yonggang Zhang, Yonghong Wang, Y. Zhao","doi":"10.12989/CAC.2021.27.4.369","DOIUrl":"https://doi.org/10.12989/CAC.2021.27.4.369","url":null,"abstract":"This article deals with the frequency analysis of viscoelastic sandwich disk with graphene nano-platelets (GPLs) reinforced viscoelastic concrete (GPLRVC) face sheets and honeycomb core. The honeycomb core is made of aluminum due to its low weight and high stiffness. The rule of the mixture and modified Halpin–Tsai model are engaged to provide the effective material constant of the concrete. By employing Hamilton's principle, the governing equations of the structure are derived and solved with the aid of the Generalize Differential Quadrature Method (GDQM). In this paper, viscoelastic properties are modeled according to Kelvin-Voigt viscoelasticity. The deflection as the function of time can be solved by the fourth-order Runge-Kutta numerical method. Afterward, a parametric study is carried out to investigate the effects of the outer to inner radius ratio, hexagonal core angle, thickness to length ratio of the concrete, the weight fraction of GPLs into concrete, and the thickness of honeycomb core to inner radius ratio on the frequency of the viscoelastic sandwich disk with honeycomb core and FGGPLRVC face sheet.","PeriodicalId":50625,"journal":{"name":"Computers and Concrete","volume":"73 6 1","pages":"369"},"PeriodicalIF":4.1,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74753260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Dynamic response of functionally graded plates with a porous middle layer under time-dependent load 含多孔中间层的功能梯度板在时变荷载作用下的动力响应

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-03-01 DOI: 10.12989/CAC.2021.27.3.269

N. Dergachova, G. Zou

引用次数: 0

Vibration and damping characteristics of the masonry wallstrengthened with bonded fibre composite patch with viscoelastic adhesive layer 粘弹性粘接层纤维复合贴片加固砌体墙体的振动和阻尼特性

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-03-01 DOI: 10.12989/CAC.2021.27.3.253

S. Laib, S. Meftah, Hadj Youzera, N. Ziane, A. Tounsi

引用次数: 0

Investigation of continuous and discontinuous contact cases in the contact mechanics of graded materials using analytical method and FEM 用解析法和有限元法研究梯度材料接触力学中连续和不连续接触情况

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-03-01 DOI: 10.12989/CAC.2021.27.3.199

Murat Yaylacı, G. Adıyaman, Erdal Öner, A. Birinci

{"title":"Investigation of continuous and discontinuous contact cases in the contact mechanics of graded materials using analytical method and FEM","authors":"Murat Yaylacı, G. Adıyaman, Erdal Öner, A. Birinci","doi":"10.12989/CAC.2021.27.3.199","DOIUrl":"https://doi.org/10.12989/CAC.2021.27.3.199","url":null,"abstract":"The aim of this paper was to examine the continuous and discontinuous contact problems between the functionally graded (FG) layer pressed with a uniformly distributed load and homogeneous half plane using an analytical method and FEM. The FG layer is made of non-homogeneous material with an isotropic stress–strain law with exponentially varying properties. It is assumed that the contact at the FG layer-half plane interface is frictionless, and only the normal tractions can be transmitted along the contacted regions. The body force of the FG layer is considered in the study. The FG layer was positioned on the homogeneous half plane without any bonds. Thus, if the external load was smaller than a certain critical value, the contact between the FG layer and half plane would be continuous. However, when the external load exceeded the critical value, there was a separation between the FG layer and half plane on the finite region, as discontinuous contact. Therefore, there have been some steps taken in this study. Firstly, an analytical solution for continuous and discontinuous contact cases of the problem has been realized using the theory of elasticity and Fourier integral transform techniques. Then, the problem modeled and twodimensional analysis was carried out by using ANSYS package program based on FEM. Numerical results for initial separation distance and contact stress distributions between the FG layer and homogeneous half plane for continuous contact case; the start and end points of separation and contact stress distributions between the FG layer and homogeneous half plane for discontinuous contact case were provided for various dimensionless quantities including material inhomogeneity, distributed load width, the shear module ratio and load factor for both methods. The results obtained using FEM were compared with the results found using analytical formulation. It was found that the results obtained from analytical formulation were in perfect agreement with the FEM study.","PeriodicalId":50625,"journal":{"name":"Computers and Concrete","volume":"111 1","pages":"199"},"PeriodicalIF":4.1,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87762393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Prediction of the dynamic properties in rubberized concrete 橡胶混凝土动力性能的预测

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-03-01 DOI: 10.12989/CAC.2021.27.3.185

A. Habib, U. Yildirim

{"title":"Prediction of the dynamic properties in rubberized concrete","authors":"A. Habib, U. Yildirim","doi":"10.12989/CAC.2021.27.3.185","DOIUrl":"https://doi.org/10.12989/CAC.2021.27.3.185","url":null,"abstract":"Throughout the previous years, many efforts focused on incorporating non-biodegradable wastes as a partial replacement and sustainable alternative for natural aggregates in cement-based materials. Currently, rubberized concrete is considered one of the most important green concrete materials produced by replacing natural aggregates with rubber particles from old tires in a concrete mixture. The main benefits of this material, in addition to its importance in sustainability and waste management, comes from the ability of rubber to considerably damp vibrations, which, when used in reinforced concrete structures, can significantly enhance its energy dissipation and vibration behavior. Nowadays, the literature has many experimental findings that provide an interesting view of rubberized concrete's dynamic behavior. On the other hand, it still lacks research that collects, interprets, and numerically investigates these findings to provide some correlations and construct reliable prediction models for rubberized concrete's dynamic properties. Therefore, this study is intended to propose prediction approaches for the dynamic properties of rubberized concrete. As a part of the study, multiple linear regression and artificial neural networks will be used to create prediction models for dynamic modulus of elasticity, damping ratio, and natural frequency.","PeriodicalId":50625,"journal":{"name":"Computers and Concrete","volume":"7 1","pages":"185"},"PeriodicalIF":4.1,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90304438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Effect of pumice powder and artificial lightweight fine aggregate on self-compacting mortar 浮石粉与人工轻质细骨料对自密实砂浆的影响

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-03-01 DOI: 10.12989/CAC.2021.27.3.241

Serkan Etli, Selim Cemalgil, O. Onat

{"title":"Effect of pumice powder and artificial lightweight fine aggregate on self-compacting mortar","authors":"Serkan Etli, Selim Cemalgil, O. Onat","doi":"10.12989/CAC.2021.27.3.241","DOIUrl":"https://doi.org/10.12989/CAC.2021.27.3.241","url":null,"abstract":"An experimental program was conducted to investigate the fresh properties, mechanical properties and durability \u0000characteristics of the self-compacting mortars (SCM) produced with pumice powder and Artificial Lightweight Fine Aggregate (aLWFA). aLWFA was produced by using fly ash. A total of 16 different mixtures were designed with a constant water-binder ratio of 0.37, in which natural sands were partially replaced with aLWFA and pumice powder at different volume fractions of 5%, 10% and 15%. The artificial lightweight aggregates used in this study were manufactured through cold bonding pelletisation of 90% of class-F fly ash and 10% of Portland cement in a tilted pan with an ambient temperature and moisture content. Flowability tests were conducted on the fresh mortar mixtures beforehand, to determine the self-compacting \u0000characteristics on the basis of EFNARC. To determine the conformity of the fresh mortar characteristics with the standards, mini-slump and mini-V-funnel tests were carried out. Hardened state tests were conducted after 7, 28 and 56 days to determine the flexural strength and axial compressive strength respectively. Durability, sorptivity, permeability and density tests were conducted at the end of 28 days of curing time. The test results showed that the pumice powder replacement improved both the fresh state and the hardened state characteristics of the mortar and the optimum mixture ratio was determined as 15%, considering other studies in the literature. In the aLWFA mixtures used, the mechanical and durability characteristics of the \u0000modified compositions were very close to the control mixture. It is concluded in this study that mixtures with pumice powder replacement eliminated the negative effects of the aLWFA in the mortars and made a positive contribution.","PeriodicalId":50625,"journal":{"name":"Computers and Concrete","volume":"3 1","pages":"241"},"PeriodicalIF":4.1,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87610236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Strength and strain modeling of CFRP-confined concrete cylinders using ANNs 基于神经网络的cfrp约束混凝土圆柱体强度与应变建模

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-03-01 DOI: 10.12989/CAC.2021.27.3.225

Onur Ozturk

{"title":"Strength and strain modeling of CFRP-confined concrete cylinders using ANNs","authors":"Onur Ozturk","doi":"10.12989/CAC.2021.27.3.225","DOIUrl":"https://doi.org/10.12989/CAC.2021.27.3.225","url":null,"abstract":"Carbon fiber reinforced polymer (CFRP) has extensive use in strengthening reinforced concrete structures due to its high strength and elastic modulus, low weight, fast and easy application, and excellent durability performance. Many studies have been carried out to determine the performance of the CFRP confined concrete cylinder. Although studies about the prediction of confined compressive strength using ANN are in the literature, the insufficiency of the studies to predict the strain of confined concrete cylinder using ANN, which is the most appropriate analysis method for nonlinear and complex problems, draws attention. Therefore, to predict both strengths and also strain values, two different ANNs were created using an extensive experimental database. The strength and strain networks were evaluated with the statistical parameters of correlation coefficients (R2), root mean square error (RMSE), and mean absolute error (MAE). The estimated values were found to be close to the experimental results. Mathematical equations to predict the strength and strain values were derived using networks prepared for convenience in engineering applications. The sensitivity analysis of mathematical models was performed by considering the inputs with the highest importance factors. Considering the limit values obtained from the sensitivity analysis of the parameters, the performances of the proposed models were evaluated by using the test data determined from the experimental database. Model performances were evaluated comparatively with other analytical models most commonly used in the literature, and it was found that the closest results to experimental data were obtained from the proposed strength and strain models.","PeriodicalId":50625,"journal":{"name":"Computers and Concrete","volume":"AES-4 1","pages":"225"},"PeriodicalIF":4.1,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84470573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A proposal for an approach for meso scale modeling for concrete based on rigid body spring model 提出了一种基于刚体弹簧模型的混凝土细观尺度建模方法

IF 4.1 4区工程技术

Computers and Concrete Pub Date : 2021-03-01 DOI: 10.12989/CAC.2021.27.3.283

Chao Zhao, Z. Shi, Xingu Zhong

{"title":"A proposal for an approach for meso scale modeling for concrete based on rigid body spring model","authors":"Chao Zhao, Z. Shi, Xingu Zhong","doi":"10.12989/CAC.2021.27.3.283","DOIUrl":"https://doi.org/10.12989/CAC.2021.27.3.283","url":null,"abstract":"Existing meso-scale models of concrete need to refine the mesh grids of aggregate and cement mortar, which may greatly reduce the computational efficiency. To overcome this problem, a novel meso-scale modeling strategy, which is based on rigid body spring method and Voronoi diagram, is proposed in this study to establish the meso-scale model of concrete. Firstly, establish numerical aggregate models according to user-defined programs. Circle aggregates are adopted due to their high efficiency in generation and packing process, and the grading of aggregate are determined according to the distribution curve proposed by Full and Thompson; Secondly, extract the centroids of aggregates, and then develop the Voronoi diagram in which aggregate centroids are defined as initial scatters; Finally, establish the rigid body spring model for concrete based on the Voronoi diagram. Aggregates are represented by rigid blocks, and assumed to be unbreakable. Cement mortar is concentrated into the interface between adjacent blocks and represented by two uniform springs. The number of grids is consistent with that of aggregates in specimens, and no mesh-refinement of aggregates and cement mortar is required. The accuracy and efficiency of the proposed modeling strategy are firstly identified by comparing the numerical results with the experimental ones, and then the applicability of the proposed strategy with different volume percentage occupied by aggregates is investigated.","PeriodicalId":50625,"journal":{"name":"Computers and Concrete","volume":"120 1","pages":"283"},"PeriodicalIF":4.1,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78513210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0