B.K. Raghu Prasad¹, T.V.R.L. Rao¹, A.R. Gopalakrishnan¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.3, pp. 179-196, 2009, DOI:10.3970/icces.2009.009.179

Abstract A simple numerical method namely Initial Stiffness Method using finite element method has been employed to study the size effect which is prominent in concrete structures. Numerous experimental investigations performed on notched plain concrete beams subjected to three point or four-point bending have revealed the fracture process to be dependent on size of the structural member. It was found that, the nominal stress at maximum load decreases as the size of the structure increases. The nominal stress at failure on the characteristic dimension of structure is termed as size effect. This has also been explained in energy concepts as, the… More >

Doo Kie Kim¹, Seong Kyu Chang¹, Sang Kil Chang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.1, pp. 29-34, 2007, DOI:10.3970/icces.2007.002.029

Abstract Accurate and realistic strength estimation before the placement of concrete is highly desirable. In this study, the advanced probabilistic neural network (APNN) was proposed to reflect the global probability density function by summing the heterogeneous local probability density function automatically determined in the individual standard deviation of variables. Currently, the estimation of the compressive strength of concrete is performed by a probabilistic neural network (PNN) on the basis of concrete mix proportions, and the PNN is improved by the iteration method. However, an empirical method has been incorporated to specify the smoothing parameter in the PNN technique, causing significant uncertainty… More >

Jieping Liu¹, Lingxin Zhang^1,*, Haohao Zhang², Tao Liu¹

Structural Durability & Health Monitoring, Vol.13, No.2, pp. 123-142, 2019, DOI:10.32604/sdhm.2019.04486

Abstract As there is a lack of earthquake damage data for factory buildings with seismic fortifications in China, seismic vulnerability analysis was performed by numerical simulation in this paper. The earthquake-structure analysis model was developed with considering the influence of uncertainties of the ground motion and structural model parameters. The small-size sampling was conducted based on the Latin hypercube sampling and orthogonal design methods. Using nonlinear analysis, the seismic vulnerability curves and damage probability matrix with various seismic fortification intensities (SFI) were obtained. The seismic capacity of the factory building was then evaluated. The results showed that, with different designs at… More >

Costas P. Providakis^1,*, Stavros E. Tsistrakis¹, Evangelos V. Liarakos¹

Structural Durability & Health Monitoring, Vol.12, No.4, pp. 257-279, 2018, DOI:10.32604/sdhm.2018.04607

Abstract In the present study a new structural health monitoring (SHM) technique is proposed as well as a new damage index based on 2-D error statistics. The proposed technique combines the electromechanical impedance technique (EMI) which is based on the use of piezoelectric Lead Zirconate Titanate (PZT) patches and Scanning Laser Doppler Vibrometry (SLDV) for damage detection purposes of concrete structures and early age monitoring. Typically the EMI technique utilizes the direct and inverse piezoelectric effect of a PZT patch attached to a host structure via an impedance analyzer that is used for both the actuation and sensing the response of… More >

Chengquan Wang¹, Yun Zou^1,*, Tianqi Li¹, Jie Ding¹, Xiaoping Feng¹, Tiange Lei¹

Structural Durability & Health Monitoring, Vol.12, No.2, pp. 99-110, 2018, DOI: 10.3970/sdhm.2018.02061

Abstract A kind of concrete-filled lattice rectangular steel tube (CFLRST) column was put forward. The numerical simulation was modeled to analyze the mechanical characteristic of CFLRST column. By comparing the load-deformation curves from the test results, the rationality and reliability of the finite element model has been confirmed, moreover, the change of the section stiffness and stress in the forcing process and the ultimate bearing capacity of the column were analyzed. Based on the model, the comparison of ultimate bearing capacity and ductility between CFLRST column and reinforced concrete (RC) column were also analyzed. The results of the finite element analysis… More >

Yang Li^1,*, Dongwei Yang¹, Jiangkun Zhang¹

Structural Durability & Health Monitoring, Vol.12, No.1, pp. 51-63, 2018, DOI:10.3970/sdhm.2018.012.051

Abstract Diffusion behavior of chloride ion in reinforced concrete under bending moment was studied by taking the ratio of bending moment to ultimate flexural capacity as load level indicator. The function relationship between load level and chloride ion diffusion coefficient was established, based on that the limit state equation of the chloride ion critical concentration and chloride ion concentration on surface of the steel bar was established. Then by applying Monte-Carlo method the corrosion probability of reinforcement under different load levels in splash zone was calculated. Calculation results demonstrated that compared with the durability reliability index considering loading effect, the reliability… More >

Ricardo Perera¹

CMC-Computers, Materials & Continua, Vol.1, No.2, pp. 153-172, 2004, DOI:10.3970/cmc.2004.001.153

Abstract Epoxy-bonding a composite plate to the tension face is an effective technique to repair reinforced concrete beams since it increases their strength and rigidity. In this paper, the structural behavior of reinforced concrete beams with fibre reinforced polymer (FRP) plates is studied numerically. For it, a numerical damage model is used in order to predict their strength, stiffness and failure modes observed in experimental tests taking into account the influence of different variables such as the amount of steel reinforcement, the type and amount of external reinforcement, the plate length, etc. The consideration of concrete cracking and the yielding of… More >

Xiaoying Zhuang^1,2,*, Shuai Zhou^3,4

CMC-Computers, Materials & Continua, Vol.59, No.1, pp. 57-77, 2019, DOI:10.32604/cmc.2019.04589

Abstract Advances in machine learning (ML) methods are important in industrial engineering and attract great attention in recent years. However, a comprehensive comparative study of the most advanced ML algorithms is lacking. Six integrated ML approaches for the crack repairing capacity of the bacteria-based self-healing concrete are proposed and compared. Six ML algorithms, including the Support Vector Regression (SVR), Decision Tree Regression (DTR), Gradient Boosting Regression (GBR), Artificial Neural Network (ANN), Bayesian Ridge Regression (BRR) and Kernel Ridge Regression (KRR), are adopted for the relationship modeling to predict crack closure percentage (CCP). Particle Swarm Optimization (PSO) is used for the hyper-parameters… More >

A. Ramachandra Murthy¹, Nagesh R. Iyer¹, B.K. Raghu Prasad²

CMC-Computers, Materials & Continua, Vol.31, No.3, pp. 229-252, 2012, DOI:10.3970/cmc.2012.031.229

Abstract This paper presents the advanced analytical methodologies such as Double- G and Double - K models for fracture analysis of concrete specimens made up of high strength concrete (HSC, HSC1) and ultra high strength concrete. Brief details about characterization and experimentation of HSC, HSC1 and UHSC have been provided. Double-G model is based on energy concept and couples the Griffith's brittle fracture theory with the bridging softening property of concrete. The double-K fracture model is based on stress intensity factor approach. Various fracture parameters such as cohesive fracture toughness (K_Ic^c), unstable fracture toughness (K_Ic^un) and initiation fracture toughness… More >

E. Ferretti¹

CMC-Computers, Materials & Continua, Vol.31, No.2, pp. 87-112, 2012, DOI:10.3970/cmc.2012.031.087

Abstract The present study follows a previous study on the stress and strain profiles along the cross-section of waste tire rubberized concrete plates for airport pavements, subjected to quasi-static loads [Ferretti and Bignozzi (2012)]. Further results on the in-situ performance of concrete plain and rubberized taxiways have been collected and presented here. The experimental program has been undertaken at the Guglielmo Marconi airport of Bologna (Italy). It concerns two portions of the taxiway, one built with plain concrete and one with rubberized concrete. Each portion has been fitted with strain gauges embedded in concrete for the acquisition of vertical strains. More >