Fenghua Yuan¹, Qing Zhang^1,*, Xiaozhou Xia¹

CMC-Computers, Materials & Continua, Vol.58, No.3, pp. 777-793, 2019, DOI:10.32604/cmc.2019.04182

Abstract Reinforcement corrosion directly affects the mechanical behavior of reinforced concrete structures. An electric corrosion test was conducted on a reinforced concrete test specimen, and a finite element model of the reinforcement corrosion damage was established. In addition, the damage behavior of reinforced concrete under different corrosion sediment distribution characteristics and different corrosion rates was studied. It was noted that when corrosion sediments are in a “semiellipse+semicircle” distribution, the results of numerical calculation are consistent with those obtained experimentally, reflecting the damage characteristics of reinforced concrete test specimens. Further, the results showed that the distribution characteristics of corrosion sediments greatly influence… More >

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

CMC-Computers, Materials & Continua, Vol.57, No.3, pp. 417-446, 2018, DOI:10.32604/cmc.2018.01742

Abstract The microcapsule-enabled cementitious material is an appealing building material and it has been attracting increasing research interest. By considering microcapsules as dissimilar inclusions in the material, this paper employs the discrete element method (DEM) to study the effects of loading rates on the fracturing behavior of cementitious specimens containing the inclusion and the crack. The numerical model was first developed and validated based on experimental results. It is then used to systematically study the initiation, the propagation and the coalescence of cracks in inclusion-enabled cementitious materials. The study reveals that the crack propagation speed, the first crack initiation stress, the… More >

Wenyi Yin^1,2, Xiangyun Zhang^1,2,†, Bumaliya Abulimiti^3,*, Yuzhu Liu^1,2,*, Yihui Yan^1,2, Fengbin Zhou^1,2, Feng Jin⁴

CMC-Computers, Materials & Continua, Vol.55, No.1, pp. 165-176, 2018, DOI:10.3970/cmc.2018.055.165

Abstract Dioxin is a highly toxic and caustic substance, which widely existed in the atmosphere, soil and water with tiny particles. Dioxin pollution has become a major problem that concerns the survival of mankind, which must be strictly controlled. The bond length, bond angle, energy, dipole moment, orbital energy level distribution of dioxin under the external field are investigated using DFT (density functional theory) on basis set level of B3LYP/6-31G (d, p). The results indicate that with the increase of the electric field, the length of one Carbon-Oxygen bond increases while another Carbon-Oxygen bond decreases. The energy gradually decreases with the… More >

S.D. Akbarov^1,2, T. Kocal³, T. Kepceler¹

CMC-Computers, Materials & Continua, Vol.51, No.2, pp. 105-143, 2016, DOI:10.3970/cmc.2016.051.105

Abstract The paper studies the dispersion of axisymmetric longitudinal waves in the bi-material compound circular cylinder made of linear viscoelastic materials. The investigations are carried out within the scope of the piecewise homogeneous body model by utilizing the exact equations of linear viscoelasto-dynamics. The corresponding dispersion equation is derived for an arbitrary type of hereditary operator and the algorithm is developed for its numerical solution. Concrete numerical results are obtained for the case where the relations of the constituents of the cylinder are described through fractional exponential operators. The influence of the viscosity of the materials of the compound cylinder on… More >

Neeraj Dubey¹, Geeta Agnihotri¹

CMC-Computers, Materials & Continua, Vol.45, No.1, pp. 39-56, 2015, DOI:10.3970/cmc.2015.045.039

Abstract In this paper, midrib of coconut palm leaves (MCL) was investigated for the purpose of development of natural fiber reinforced polymer matrix composites. A new natural fiber composite as MCL/polyester is developed by the hand lay-up method, and the material and mechanical properties of the fiber, matrix and composite materials were evaluated. The effect of fiber content on the tensile, flexural, impact, compressive strength and heat distortion temperature (HDT) was investigated. It was found that the MCL fiber had the maximum tensile strength, tensile modulus flexural strength, flexural modulus and Izod impact strength of 177.5MPa, 14.85GPa, 316.04MPa and 23.54GPa, 8.23KJ/m²… More >

Weijie Li¹, Haiming Huang^1,2, Bangcheng Ai³, Ye Tian¹

CMC-Computers, Materials & Continua, Vol.43, No.3, pp. 175-196, 2014, DOI:10.3970/cmc.2014.043.175

Abstract Physical and mathematical models are the key to analyze thermal behavior of charring materials in the thermal protection system of reentry vehicles subjected to aerodynamic heating. To explore the thermal behavior of charring ablator, we developed and compared two models (pyrolysis interface model and pyrolysis layer model) with pyrolysis and surface recession. Taking AVCOAT composites as an example, its nonlinear thermal behavior, which are caused by temperature dependent thermal properties, moving interfaces and moving boundary, were simulated using the calculation codes written respectively on the basis of the pyrolysis layer model and the pyrolysis interface model. Numerical results indicate that… More >

S. Zhao¹, Zichun Yang^1,2, X. G. Zhou³, X. Z. Ling⁴, L. S. Mora⁵, D. Khoshkhou⁶, J. Marrow⁵

CMC-Computers, Materials & Continua, Vol.42, No.2, pp. 103-124, 2014, DOI:10.3970/cmc.2014.042.103

Abstract Continuous SiC fiber reinforced SiC matrix composites (SiC/SiC) have been studied and developed for high temperature and fusion applications. Polymer impregnation and pyrolysis (PIP) is a conventional technique for fabricating SiC/SiC composites. In this research, KD-1 SiC fibers were employed as reinforcements, a series of coatings such as pyrocarbon (PyC), SiC and carbon nanotubes (CNTs) were synthesized as interphases, PCS and LPVCS were used as precursors and SiC/SiC composites were prepared via the PIP method. The mechanical properties of the SiC/SiC composites were characterized. Relationship between the interphase shear strength and the fracture toughness of the composites was established. X-ray… More >

Yuvaraj P¹, A Ramachra Murthy², Nagesh R Iyer³, S.K. Sekar⁴, Pijush Samui⁵

CMC-Computers, Materials & Continua, Vol.41, No.3, pp. 193-214, 2014, DOI:10.3970/cmc.2014.041.193

Abstract This paper presents fracture mechanics based Artificial Neural Network (ANN) model to predict the fracture characteristics of high strength and ultra high strength concrete beams. Fracture characteristics include fracture energy (Gf), critical stress intensity factor (KIC) and critical crack tip opening displacement (CTODc). Failure load of the beam (Pmax) is also predicated by using ANN model. Characterization of mix and testing of beams of high strength and ultra strength concrete have been described. Methodologies for evaluation of fracture energy, critical stress intensity factor and critical crack tip opening displacement have been outlined. Back-propagation training technique has been employed for updating… More >

Cherl-Hee Lee, Jonghun Lee¹

CMC-Computers, Materials & Continua, Vol.39, No.3, pp. 289-299, 2014, DOI:10.3970/cmc.2014.039.289

Abstract The broadband design of a metamaterials-based zeroth-order resonance (ZOR) mushroom antenna with an I-shaped slit is presented and experimentally studied. The presented metamaterials-based antenna uses a unit cell based on a composite right/left handed (CRLH) transmission line and can provide a ZOR frequency. By designing the I-shaped slot resonance frequency adjacently to the ZOR frequency, the presented antenna can achieve a 10-dB bandwidth enhancement of roughly 7 times with respect to a conventional rectangular-shaped mushroom structure. More >

A.I. Dimitriadis¹, N.V. Kantartzis¹ and T.D. Tsiboukis¹

CMC-Computers, Materials & Continua, Vol.39, No.3, pp. 231-265, 2014, DOI:10.3970/cmc.2014.039.231

Abstract The most important surface susceptibility models for the electromagnetic characterization of periodic metafilms, based on the dipole approximation method, are systematically analyzed in this paper. Specifically, two well-known techniques, which lead to a set of local effective surface parameters, are investigated along with a new dynamic non-local modeling algorithm. The latter formulation is properly expanded, in order to be applicable for any arbitrary periodic metafilm, irrespective of its way of excitation. The featured schemes are then directly compared toward their ability to efficiently predict the reflection and transmission properties of several lossless and lossy metafilms. Their outcomes are carefully verified… More >