Seon Doo Jo¹, Chan Kyu Park², Jae Hong Jeong², Seung Hoon Lee², Seung Hee Kwon³

CMC-Computers, Materials & Continua, Vol.27, No.3, pp. 189-210, 2012, DOI:10.3970/cmc.2011.027.189

Abstract When concrete is being pumped, a lubricating layer forms at the interface of the inner concrete and the wall of the pipe. The lubricating layer is one of the most dominant factors in determining the pumping capability, yet no study has endeavored to quantitatively estimate the thickness and rheological properties of the layer. Recently, there has been a growing demand for large-scale construction under extreme conditions, such as high-rise buildings and super-long span bridges. This demand has heightened the need for more accurate predictions of pumpability.
A possible mechanism that contributes to the formation of the lubricating layer is shear-induced… More >

Smitha Gopinath^1,2, A. Ramachandra Murthy¹, Bhaskar Srivastava¹, V. Ramesh kumar¹, Nagesh R. Iyer¹

CMC-Computers, Materials & Continua, Vol.27, No.1, pp. 73-100, 2012, DOI:10.3970/cmc.2012.027.073

Abstract The present study investigates the behavior of concrete specimens confined with woven roving glass fabrics under uniaxial compression. The fabric made up of 360G.S.M. woven roved E-glass is embedded in a polyester resin before application. Experimental investigations have been carried out on confined and unconfined concrete specimens of size 150 mm (diameter) X 300 mm (height) under a displacement controlled loading. The effect of number of layers on confinement has also been investigated. Load versus deflection plots have been obtained for all the specimens. Numerical studies have been performed on the confinement effect of the wrapped concrete specimens. A non-linear… More >

R. Chen¹, X. Han^1,2, J. Liu¹, W. Zhang¹

CMC-Computers, Materials & Continua, Vol.25, No.2, pp. 135-158, 2011, DOI:10.3970/cmc.2011.025.135

Abstract In this paper, a computational inverse technique is presented to determine the constitutive parameters of concrete based on the penetration experiments. In this method, the parameter identification problem is formulated as an inverse problem, in which the parameters of the constitutive model can be characterized through minimizing error functions of the penetration depth measured in experiments and that computed by forward solver LS-DYNA. To reduce the time for forward calculation during the inverse procedure, radial basis function approximate model is used to replace the actual computational model. In order to improve the accuracy of approximation model, a local-densifying method combined… More >

Bhashya V.¹, Ramesh G.¹, Sundar Kumar S.¹, Bharatkumar B. H.¹, Krishnamoorthy T.S.¹, Nagesh R Iyer.¹

CMC-Computers, Materials & Continua, Vol.25, No.1, pp. 47-74, 2011, DOI:10.3970/cmc.2011.025.047

Abstract Fibre-reinforced polymers (FRPs) are being introduced into a wide variety of civil engineering applications. These materials have been found to be particularly attractive for applications involving the strengthening and rehabilitation of existing reinforced concrete structures. In this paper, experimental investigations and analytical studies on four series of the concrete cylinders wrapped with FRP are presented. First series consist of concrete cylinders wrapped with one layer carbon fiber reinforced polymer (CFRP), second series concrete cylinders wrapped with two layers CFRP, in third series, concrete cylinders were wrapped with one layer glass fiber reinforced polymer (GFRP) and the fourth series consist of… More >

Mohammad Reza Salami^1,*, Ebrahim Afsar Dizaj², Mohammad Mehdi Kashani³

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 677-691, 2019, DOI:10.32604/cmes.2019.05666

Abstract The aim of this study is to investigate the dynamic performance of rectangular and circular reinforced concrete (RC) columns considering biaxial multiple excitations. For this purpose, an advanced nonlinear finite element model which can simulate various features of cyclic degradation in material and structural components is used. The implemented nonlinear fiber beam-column model accounts for inelastic buckling and low-cycle fatigue degradation of longitudinal reinforcement and can simulate multiple failure modes of RC columns under dynamic loading. Hypothetical rectangular and circular columns are used to investigate the failure modes of RC columns. A detailed ground motion selection is implemented to generate… More >

Mohammed A. Mohammed¹, Andre R. Barbosa^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 583-627, 2019, DOI:10.32604/cmes.2019.06052

Abstract A three-dimensional nonlinear modeling strategy for simulating the seismic response of slender reinforced concrete structural walls with different cross-sectional shapes is presented in this paper. A combination of nonlinear multi-layer shell elements and displacement-based beam-column elements are used to model the unconfined and confined parts of the walls, respectively. A uniaxial material model for reinforcing steel bars that includes buckling and low-cyclic fatigue effects is used to model the longitudinal steel bars within the structural walls. The material model parameters related to the buckling length are defined based on an analytical expression for reinforcing steel bars embedded in reinforced concrete… More >

Liwei Wu¹, Dan Huang^1,*, Yepeng Xu¹, Lei Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 561-581, 2019, DOI:10.31614/cmes.2019.04347

Abstract Strain hardening and strain rate play an important role in dynamic deformation and failure problems such as high-velocity impact cases. In this paper, a non-ordinary state-based peridynamic model for failure and damage of concrete materials subjected to impacting condition is proposed, taking the advantages of both damage model and non-local peridynamic method. The Holmquist-Johnson-Cook (HJC) model describing the mechanical character and damage of concrete materials under large strain, high strain rate and high hydrostatic pressure was reformulated in the framework of non-ordinary state-based peridynamic theory, and the corresponding numerical approach was developed. The proposed model and numerical approach were validated… More >

Sadık Alper YILDIZEL¹, Muhammet Ensar YİĞİT², Gökhan KAPLAN³

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.2, pp. 203-218, 2017, DOI:10.3970/cmes.2017.113.211

Abstract Glass fibre reinforced concrete placement technique generates losses due to rebound effects of the already sprayed concrete particles. Rebounded concrete amount cause a significant difference between the initial mix design and emplaced mix compositions. Apart from the structural differences, it comes with a cost increase which was resulted by the splashed concrete amount. Many factors such as viscosity and quantity of mixes dominate this rebound amount in sprayed glass fibre reinforced concrete applications depending on production technologies and processes; however, this research focuses on the spray distance and the angle of the spray gun which mainly effects the rebound amount… More >

Yong-Lin Pi¹, Mark Andrew Bradford¹

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.3, pp. 233-253, 2014, DOI:10.3970/cmes.2014.099.233

Abstract Creep and shrinkage of the concrete core of a concrete-filled steel tubular (CFST) arch under sustained loading are inevitable, and cause a long-term change of the equilibrium configuration of the CFST arch. As the equilibrium configuration changes continuously, the long-term radial and axial displacements of the CFST arch, stress distributions as well as the internal forces in the steel tube and the concrete core change substantially with time. Creep and shrinkage of the concrete core are related to a number of its material parameters such as its creep coefficient, aging coefficient, and shrinkage strain. The values of these parameters differ… More >

Shantaram Parab¹, Shreya Srivastava², Pijush Samui³, A. Ramachandra Murthy⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.101, No.2, pp. 139-158, 2014, DOI:10.3970/cmes.2014.101.139

Abstract This paper studies the applicability of Gaussian Process Regression (GPR) and Least Squares Support Vector Machines (LSSVM) to predict fracture parameters and failure load (P_max) of high strength and ultra-high strength concrete beams. Fracture characteristics include fracture energy (G_F), critical stress intensity factor (K_IC) and critical crack tip opening displacement (CTOD_C) Mathematical models have been developed in the form of relation between several input variables such as beam dimensions, water cement ratio, compressive strength, split tensile strength, notch depth, modulus of elasticity and output fracture parameters. Four GPR and four LSSVM models have been developed using MATLAB software for training… More >