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Yoshiyuki Furuya
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 1-2, 2011, DOI:10.3970/icces.2011.016.001
Abstract Gigacycle fatigue takes place in high-strength steel. In this case, fish-eye fracture eliminates a conventional fatigue limit. This means that the fish-eye fracture is a key to understand the gigacycle fatigue of high-strength steel. Evaluation of gigacycle fatigue properties needs accelerated fatigue testing since gigacycle fatigue tests take long time. For example, a 10⁹-cycles fatigue test takes more than 3 months at conventional 100 Hz. For this acceleration, ultrasonic fatigue testing is a very powerful tool since it achieves 20 kHz and completes the 10⁹-cycles in a day. However, frequency effects must sufficiently be investigated before using the ultrasonic fatigue… More >

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Q. Chen, K. Kariya
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 3-4, 2011, DOI:10.3970/icces.2011.016.003
Abstract Abstract Al alloys have been widely used as engineering materials in many machines and structures because of their excellent properties such as high specific strength, high resistance to corrosion and easy to recycle. Especially, high strength Al alloys are effective to reduce environment load through achieving low fuel consumption in automobile engines. On the other hand, high strength Al alloys have no definite fatigue limit and their fatigue strengths are very low in comparison with their high static strengths. It is important to know the fatigue strength of high strength Al alloys in the long life region beyond 10⁷ cycles… More >

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643

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LIU Yong-jie, TIAN Ren-hui, OUYANG Qiao-lin, WANG Qing-yuan
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 5-6, 2011, DOI:10.3970/icces.2011.016.005
Abstract Ti-6Al-4V is widely used in biology engineering as well medical implant. Clinical investigations show that TC4 implant could have rupture of passivation film and visible corrosion. To predict service life of the Ti-6Al-4V implant, it is necessary to study its ultra-high cycle fatigue behaviors in physiological environment exceeding 10⁷ cycles. In this paper, using the ultrasonic fatigue testing technique, the high cycle and ultra-high cycle fatigue properties of Ti-6Al-4V subjection to simulated body fluid (SBF) in body temperature were studied and compared with that of normal Ti-6Al-4V. The experimental results show that SBF subjection has slight influence on the ultra-high… More >

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655

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T. Sakai, W. Li, B. Lian, N. Oguma
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 7-8, 2011, DOI:10.3970/icces.2011.016.007
Abstract Long term use of mechanical products provides us a lot of positive environmental effects such as saving resources, saving energy, reducing environmental load to globe and reducing the industrial wastes. Thus, fatigue property of metallic materials in very high cycle regime such as gigacycles has been a new important subject to ensure the long durability of actual mechanical structures during the latest decades. From this point of view, fatigue tests in the long life regime were performed for various kinds of metallic materials by many researchers and a series of experimental results were reported. One of most typical aspect in… More >

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687

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James D. Turner, Manoranjan Majji, John L. Junkins
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 9-10, 2011, DOI:10.3970/icces.2011.016.009
Abstract Numerical integration methods have been developed for predicting the evolution of the response of dynamical systems. Standard algorithms approach approximate the solution at a future time by introducing using a truncated power series representation that attempts to recover an n-th order Taylor series approximation, while only numerically sampling a single derivative model. Successful applications of this approach include: (1) Runge-Kutta methods which build up an approximation for a single step; (2) Predictor-Correction methods that use several back solutions to approximate the next step, and (3) Gear methods for handling stiff differential equations. The major innovation of this paper is the… More >

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607

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James D.Turner, Manoranjan Majji, John L. Junkins
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 11-12, 2011, DOI:10.3970/icces.2011.016.011
Abstract Modeling uncertainty for nonlinear systems is often handled by developing a mathematical model, defining suitable parameters, establishing suitable initial conditions and numerically integrating the system response in order to study the behavior of the system. The potential range of behaviors that can be realized is assessed by varying the model parameters, integrating the response, and recording the changes in the system behaviors. In theory this process is straightforward for implementing. The only potential barrier to carrying out the repeated integrations of the system dynamics is the availability of powerful computer resources that can provide the density of sample points required… More >

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627

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Yuan-Qi Li, Li-Ping Wang, Zu-Yan Shen
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 13-14, 2011, DOI:10.3970/icces.2011.016.013
Abstract In structural design, sometimes analysis methods in available specifications cannot be used directly for new materials or new structural configurations. A common way is to test and check the behavior in question of the prototype units including complete or parts of structures, individual members or connections for design assessment. How to directly obtain the design capacity with an expected reliability level according to the related codes from test results is a critical issue. Currently, there isn't any explicit specification for the above issues in Chinese codes, and few references are available. In this paper, referring to Australian specifications for Cold-formed… More >

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641

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Syh-Tsang Jenq, Yuen-Sheng Chiu
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 15-16, 2011, DOI:10.3970/icces.2011.016.015
Abstract Current work studies the transient hydroplaning behaviors of 200 kPa inflated pneumatic radial tires with V-shaped grooved tread patterns and then rolls over the water film with a thickness of 10 mm. we also perform complete numerical simulations in order to know how to elevate the hydroplaning capability. Tires were numerically loaded with a quarter car weight of 4 kN on initial step, and then subsequently accelerated from rest rolling over a water film with a thickness of 10 mm on top of a flat roadway. Tire structure is composed of outer rubber tread and inner fiber reinforcing composite layers.… More >

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679

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Xiuling Wang, Darrell W. Pepper
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 17-18, 2011, DOI:10.3970/icces.2011.016.017
Abstract A high-order numerical model is developed to simulate species transport for use in emergency response situations. The model includes employing an hp-adaptive finite element technique to construct velocity fields within complex geometries as well as over irregular terrain features. Lagrangian particles are used to display contaminant dispersion patterns. The use of hp-adaptive finite element methods permit both automatic local refinement and unrefinement of the computational grid - a fine mesh is developed in those regions where flow features and/or species gradients change rapidly while a coarse mesh is employed where flow and transport are unvarying (or smooth). The use of… More >

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598

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Chih-Wen Chang
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 19-20, 2011, DOI:10.3970/icces.2011.016.019
Abstract In this study, we propose a new numerical approach for solving the nonhomogeneous backward heat conduction problems (BHCPs). A fictitious time I" is used to transform the dependent variable u(x, t) into a new one by (1+I")u(x, t)=: v(x, t, I"), such that the original nonhomogeneous heat conduction equation is written as a new parabolic type partial differential equation in the space of (x, t, I"). Besides, a fictitious viscous damping coefficient can be employed to strengthen the stability of numerical integration of the discretized equations by utilizing a group preserving scheme. Several numerical instances illustrate that the present algorism… More >

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638

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Jie Qu, Bingye Xu, Quanlin Jin
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 21-22, 2011, DOI:10.3970/icces.2011.016.021
Abstract Large macro-micro coupled constitutive models, which describe metal flow and microstructure evolution during metal forming, are sometimes overparameterized with respect to given sets of experimental datum. This results in poorly identifiable or nonidentifiable model parameters. In this paper, a systemic parameter identification method for the large macro-micro coupled constitutive models is proposed. This method is based on the global and local identifiability analysis, in which two identifiability measures are adopted. The first accounts for the sensitivity of model results to single parameters, and the second accounts for the degree of near-linear dependence of sensitivity functions of parameter subsets. The global… More >

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709

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H. Wang, P.D. Wu, K.W. Neale
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 23-24, 2011, DOI:10.3970/icces.2011.016.023
Abstract Large strain homogeneous simple shear of Hexagonal Close Packed (HCP) polycrystals is first studied numerically. The analyses are based on the classical Taylor model and the Visco-Plastic Self-Consistent (VPSC) model with various Self-Consistent Schemes (SCSs). In these polycrystal plasticity models, both slip and twinning contribute to plastic deformations. The simple shear results are then extended to the case of solid circular bars under large strain fixed-end torsion, where it is assumed that the solid bar has the same mechanical properties as the element analyzed for large strain simple shear. It is shown that the predicted second-order axial force is very… More >

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620

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Norman Hecht
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 25-26, 2011, DOI:10.3970/icces.2011.016.025
Abstract The torque-free rotation of a rigid body has long been a topic of interest to physicists, mathematicians and engineers, including Euler in the 18th century, and continuing to the present day. Numerical solutions to Euler's equations are easy to achieve in an era of cheap computation, but classic solutions to the problem have used principles of angular momentum and energy to develop geometric insights to the problem. Static diagrams can help display these insights, but modern computer graphics hardware and software can truly bring these solutions to life via user-controlled animation.
Besides making visible such abstractions as the angular momentum… More >

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985

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John E Hurtado
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 27-28, 2011, DOI:10.3970/icces.2011.016.027
Abstract The torque-free rotational motion of an asymmetric rigid body is considered. Rather than focus on specific attitude coordinates, a new solution of the attitude matrix in terms of elliptic and circular functions is presented. The approach builds the attitude matrix using orthogonality properties and the concept of integrals of motion. The attitude matrix can give rise to all attitude coordinates, and one convenient set for the current situation is introduced. More >

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655

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Deli Gao, Zengxin Zhao
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 29-30, 2011, DOI:10.3970/icces.2011.016.029
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 steel in stimulant solution… More >

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658

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Y.C. Shiah, C.L. Tan
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 31-32, 2011, DOI:10.3970/icces.2011.016.031
Abstract In the boundary element method (BEM), interior point solutions for the displacements and the stresses at an interior point of an elastic body are obtained through the numerical evaluation of the Somigliana's identities. It is carried out as a secondary exercise in the BEM analysis, after the boundary integral equation (BIE) has been solved for all the unknown displacements and tractions on the surface of the domain. In the integrals of these identities, the integrands contain terms with up to second order derivatives of the Green's function for the displacements of the elastic problem.

The Green's function, or fundamental… More >

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