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 More >

Deli Gao^1,2, Lianzhong Sun^1,3, Hongshu Wei⁴, Shunwen Wang⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.2, pp. 143-162, 2012, DOI:10.3970/cmes.2012.089.143

Abstract Due to the complexity of forces acting on the down-hole tubular strings in extended reach drilling (ERD), the factors which influence the process should be taken into account as much as possible, in order to predict the down-hole drag & torque more accurately. This can help us to identify and prevent the problems related to downhole drag & torque in ERD. The effects of such factors, as the tubular buckling, the buoyancy, the mechanical resistance and the friction reducer, on down-hole drag & torque, are taken into account in this paper, in order to improve… More >

Deli Gao¹, Feng Qian¹, Huikai Zheng¹

CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.1, pp. 1-16, 2012, DOI:10.3970/cmes.2012.089.001

Abstract In deepwater wells for exploration and exploitation of oil & gas, the wellhead structure is of importance, and the annular pressure cannot be released after the casing hanger is set. The pressure changes in the casing annuli, caused by the temperature changes during the drilling and production processes, will increase the risk of failure of the casing. Therefore, a study of the safety of the casing in deepwater wells, by considering the complex engineering factors, will be of both academic as well as practical significance. In this paper, a model for the interactions among the… More >

Miaoxia Xie¹, Yueming Li¹, Hualing Chen^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.1, pp. 65-78, 2012, DOI:10.3970/cmes.2012.085.065

Abstract Energy finite element method(EFEM) is a promising method to solve high-frequency vibro-acoustic problem. Energy boundary element method (EBEM) is an effective way to compute high-frequency sound radiation in the unbounded medium. Vibro-acoustic coupling of cavity structure in anechoic chamber includes both the interior acoustic field and unbounded exterior acoustic field. In order to predict this kind of high-frequency vibro-acoustic coupling problem in anechoic chamber, an approach combined EFEM and EBEM is developed in this paper. As a numerical example, the approach is applied to solve the high-frequency vibro-acoustic coupling response of a cubic cavity structure More >

Zaobao Liu^1,2, Weiya Xu¹, Jianfu Shao²

CMES-Computer Modeling in Engineering & Sciences, Vol.84, No.2, pp. 99-122, 2012, DOI:10.3970/cmes.2012.084.099

Abstract In this paper, the Gauss process is proposed for application on landslide displacement analysis and prediction with dynamic crossing validation. The prediction problem using noisy observations is first introduced. Then the Gauss process method is proposed for modeling non-stationary series of landslide displacements based on its ability to model noisy data. The monitoring displacement series of the New Wolong Temple Landslide is comparatively studied with other methods as an instance to implement the strategy of the Gauss process for predicting landslide displacement. The dynamic crossing validation method is adopted to manage the displacement series so… More >

Cane Tulic^1,a, Miodrag Lazic^2,a, Emina Savic^3,a, Dusan Popadic³, Jelena Djukic¹, Dusan Spasic², Milos Markovic³, Zorica Ramic³, Marija Mostarica-Stojkovic³, Vladimir Trajkovic³

European Cytokine Network, Vol.22, No.4, pp. 169-174, 2011, DOI:10.1684/ecn.2011.0292

Abstract The aim of the study was to correlate the preoperative activity of Th1 and Th17 cytokine axes with the development of sepsis after radical cystectomy. The study involved twenty patients with the infiltrative transitional cell carcinoma of the urinary bladder without previous radiotherapy/chemotherapy, who underwent open radical cystectomy with urinary diversion. Preoperative plasma concentrations of Th1 cytokines interleukin 12 (IL-12) and interferon gamma (IFN-γ), and Th17 cytokines IL-23 and IL-17, were measured using ELISA. Preoperative expression of mRNA for IL-12p35, IFN-γ, IL-23p19 and IL-17 was quantified by real-time RT-PCR using mRNA extracted from peripheral blood… More >

Sujuan Guo, Guozheng Kang, Juan Zhang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 121-122, 2011, DOI:10.3970/icces.2011.018.121

Abstract With a newly developed homogenization cyclic constitutive model of particle reinforced metal matrix composites (Guo et al., 2011), the effects of tangent operators, i.e., continuum and algorithmic tangent operators [defined by Doghri and Ouaar (2003)] on the accuracy of the developed meso-mechanical constitutive model to predict the monotonic tensile and uniaxial ratchetting deformation of SiCP/6061Al composites were investigated in this work. The predicted results were obtained by the developed model with the choices of different tangent operators and various magnitudes of loading increments. Some useful accuracy comparison and error analysis on the predicted results were More >

Dong Hee Park, Do Kyun Kim, Han Byul Kim, Jung Kwan Seo, Bong JuKim, Jeom Kee Paik, Satya N. Atluri

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.2, pp. 59-60, 2011, DOI:10.3970/icces.2011.019.059

Abstract The objective of this paper is to develop a simple and accurate prediction method for the ultimate strength calculations of ship hulls subject to vertical bending moments. The method is based on a credible bending stress distribution over the hull cross-section presumed at the ultimate limit state. The accuracy of this method is demonstrated through comparison with computations obtained using more refined methods, such as nonlinear finite element method, intelligent super-size finite element method, and idealized structural unit method. Statistical analysis of the hull girder ultimate strength based on comparisons among the various computations is More >

Deli Gao¹, Zengxin Zhao²

CMC-Computers, Materials & Continua, Vol.26, No.2, pp. 157-166, 2011, DOI:10.3970/cmc.2011.026.157

Abstract The research on casing corrosion in sour environment by a synergism of sweet corrosion and H₂S corrosion has become the basis of casing selection and casing string safety evaluation with more and more sour reservoirs containing high H₂S concentration being developed. It is essential to scientifically utilize casing service ability and reasonably control production rate of gas well to achieve the effective and safe developing of gas resources during the safety period of casing service with a precise casing life prediction. Scanning electron microscopy and tensile testing were applied to investigate the corrosion of TP110TS tube More >

W. Liu, X. Y. Su, Y. R. An, K. F. Huang¹

CMC-Computers, Materials & Continua, Vol.25, No.2, pp. 177-194, 2011, DOI:10.3970/cmc.2011.025.177

Abstract Local buckling is a typical failure mode of large scale composite wind turbine blades. A procedure for predicting the onset and location of local buckling of composite wind turbine blades under aerodynamic loads is proposed in this paper. This procedure is distinct from its counterparts in adopting the pressure distributions obtained from Computational Fluid Dynamics (CFD) calculations as the loads. The finite element method is employed to investigate local buckling resistance of the composite blade. To address the mismatch between the unstructured CFD grids of the blade surface and the finite shell elements used during More >