Zhiliang Wang^1,*, Youpeng Huang¹, Feng Xiong¹

CMC-Computers, Materials & Continua, Vol.60, No.3, pp. 1189-1206, 2019, DOI:10.32604/cmc.2019.04972

Abstract This article reports numerical results investigating the damage evolution and spatial distribution characteristics of intact and jointed rockmass subjected to blast loading. The behaviors of rock material are described by the Holmquist- Johnson-Cook (HJC) constitutive model incorporated in the finite element software LS-DYNA. Results indicate that the damage distribution shows a reverse S-shape attenuation with the increase of the distance from borehole, and a better goodness of fit with the Logistic function is observed. In the single-hole blasting of jointed rockmass, there are two types of regions around the intersection of borehole and joint in which the damage degree is… More >

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 >

Yugai Huang ^{1, 2, *}

CMC-Computers, Materials & Continua, Vol.57, No.3, pp. 485-494, 2018, DOI:10.32604/cmc.2018.03112

Abstract It has been demonstrated that low energy electrons (LEEs) can induce serious DNA damages including bases loss and even single and double strand breaks. Experiments also showed that LEE induced DNA damages will be reduced with the presence of amino acids. For understanding of the protection of amino acids to DNA, the stability of 6 kinds of thymine and glycine (T-g) dimers with planar configurations with an excess electron were studied with density functional theory (DFT) method. The results show that, when the excess electron is vertically attached, all the dimers become more active with higher energy. After re-optimization, 4… More >

Yi Xue^1,2,3, Faning Dang², Rongjian Li², Liuming Fan², Qin Hao⁴, Lin Mu², Yuanyuan Xia²

CMC-Computers, Materials & Continua, Vol.54, No.1, pp. 43-59, 2018, DOI:10.3970/cmc.2018.054.043

Abstract In the seepage-stress-damage coupled process, the mechanical properties and seepage characteristics of coal are distinctly different between pre-peak stage and post-peak stage. This difference is mainly caused by damage of coal. Therefore, in the process of seepage and stress analysis of coal under the influence of excavation or mining, we need to consider the weakening of mechanical properties and the development of fractures of damaged coal. Based on this understanding, this paper analyzes the influence of damage on mechanics and seepage behavior of coal. A coupled model is established to analyze the seepage-stress-damage coupled process of coal. This model implemented… More >

Zhengong Zhou¹, Shuang Tian^1,2, Jiawei Zhang³

CMC-Computers, Materials & Continua, Vol.52, No.2, pp. 105-121, 2016, DOI:10.3970/cmc.2016.052.105

Abstract The methods of numerical simulation and test are combined to analyze the impact behavior of glass fiber reinforced aluminum alloy laminate (GLARE). A new failure criteria is proposed to obtain the impact failure of GLARE, and combined with material progressive damage method by writing code of LS-DYNA. Low velocity impact test of GLARE is employed to validate the feasibility of the finite element model established. The simulation results have been shown that progressive damage finite element model established is reliable. Through the application of the finite element model established, the delamination of GLARE evolution progress is simulated, various failure modes… More >

G. Smith¹, E. Schlangen², P.E.J. Flewitt³, A.G. Crocker⁴, A. Hodgkins⁵

CMC-Computers, Materials & Continua, Vol.51, No.3, pp. 163-185, 2016, DOI:10.3970/cmc.2016.051.163

Abstract Two linked models have been developed to explore the relationship between the amount of porosity arising in service from both radiolytic oxidation and fast neutron damage that influences both the strength and the force-displacement (load-displacement) behaviour and crack propagation in pile grade A graphite used as a nuclear reactor moderator material. Firstly models of the microstructure of the porous graphite for both unirradiated and irradiated graphite are created. These form the input for the second stage, simulating fracture in lattice-type finite element models, which predicts force (load)-displacement and crack propagation paths. Microstructures comprising aligned filler particles, typical of needle coke,… More >

Shifeng Xue^1,2, Xiuxing Zhu^1,2, Lin Zhang³, Shenghu Zhu⁴, Guigen Ye^1,5

CMC-Computers, Materials & Continua, Vol.51, No.1, pp. 21-42, 2016, DOI:10.3970/cmc.2016.051.021

Abstract A perforating hole is a channel through which the oil and gas in a reservoir pass into the production well bore. During the process of perforating due to explosion, the surrounding sandstone will be damaged to a certain extent, which will increase the well bore skin and lead to the decrease of production consequently. In this work a mechanical model of perforating damage is developed to describe the influences of perforating due to explosion on the porosity and permeability of the surrounding sandstone near the compaction zone. Based on this developed model, the important data related to the damage of… More >

H. Khellafi¹, H.M. Meddah¹, B. Ould Chikh¹, B. Bouchouicha², M. Benguediab², M. Bendouba³

CMC-Computers, Materials & Continua, Vol.49-50, No.1, pp. 31-45, 2015, DOI:10.3970/cmc.2015.049.031

Abstract The polyvinyl chloride PVC is a polymer material widely used for a large variety of applications. The present work focuses on the identification of the physical processes responsible for the mechanical properties of the PVC containing different crystallinities rate applied in large deformation and different strain rates. In order to understand the behavior of the PVC, a thermodynamic modeling is needed. Therefore, the contribution of this approach was demonstrated by experiment and numerical modeling. This comparative study demonstrates that the proposed model provides better agreement with experimental evidence. More >

Yi Xue^1,2, Feng Gao^1,2,3, Xingguang Liu⁴, Xiru Li²

CMC-Computers, Materials & Continua, Vol.47, No.2, pp. 127-141, 2015, DOI:10.3970/cmc.2015.047.127

Abstract In order to study the effect of high pressure water jet cutting technology on the permeability of single coal seam, we use the damage variable to describe the fracture distribution of coal seam, develop the 3-D finite element program based on the damage theory, and then analyze the damage distribution of coal seam after drilling and slotting. Using MTS815 rock mechanics testing system and the permeability test system, we conduct the permeability test and get the relationship between permeability and damage. Based on the damage distribution of coal seam after drilling and slotting and the permeability change law, we analyze… More >

P.A. Meroño¹, F.C. Gómez², F. Marín¹

CMC-Computers, Materials & Continua, Vol.47, No.2, pp. 107-125, 2015, DOI:10.3970/cmc.2015.047.107

Abstract This work represents a comparative study of Wavelet Transform of angular vibration signal and the traditional Fourier analysis applied to the signals of angular vibration, in one transmission which involve gears. How it is known, the elastic deformation of the material, together with the superficial irregularities of the teeth due to wear, provoke characteristic angular oscillations, which make it possible to distinguish between the regular functioning of a mechanism in good condition and the angular vibrations provoked by wear and the superficial irregularities of teeth in poor condition. However, the character of the vibrations produced in such circumstances means that… More >