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An Influence of Factors of Flow Condition, Particle and Material Properties on Slurry Erosion Resistance

Abstract

The degradation of materials due to slurry erosion is the serious problem which occurs in the power industries. The paper presents actual knowledge about an influence of individual factors connected with flow conditions, particles and material properties on the slurry erosion resistance. Among the factors connected with operating conditions, an influence of impact angle, and velocity of impact, particle concertation and liquid temperature have been described. In case of the factors connected with solid particle properties, an influence of the size, shape and hardness have been discussed. In the part devoted to the impact of material properties, due to different types of materials, the issues of resistance to erosion of slurries related to the properties of steel, ceramics and polymers are discussed separately. In the paper has been shown that a change of any of mentioned factors causes a change in the erosion rate due to the synergistic effects that accompany to slurry degradation.

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An Evaluation of Material Properties Using EMA and FEM

Abstract

The main goal of the paper is the determination of material properties from experimentally measured natural frequencies. A combination of two approaches to structural dynamics testing was applied: the experimental measurements of natural frequencies were performed by Experimental Modal Analysis (EMA) and the numerical simulations, were carried out by Finite Element Analysis (FEA). The optimization methods were used to determine the values of density and elasticity modulus of a specimen based on the experimental results.

Open access
Inverse Technique for the Viscoelastic Material Properties Characterisation

Abstract

New non-destructive technique, namely an inverse technique based on vibration tests, to characterize nonlinear mechanical properties of adhesive layers in sandwich composites has been developed. An adhesive layer is described as a viscoelastic isotropic material with storage and loss moduli which are both frequency dependent values in a wide frequency range. An optimization based on the planning of experiments and response surface technique to minimize the error functional is applied to decrease considerably the computational expenses. The developed identification technique has been successfully applied to characterize viscoelastic material properties of 3M damping polymer ISD-112 used as a core material in sandwich panels

Open access
Cavitation Erosion Resistance Influence of Material Properties

Abstract

The cavitation erosion is the phenomena that causes degradation of fluid flow machinery components due to repetitive implosion of cavitation bubbles adjacent to the solid surface. Cavitation erosion is a complex phenomenon, which includes not only hydrodynamic factors of liquid, but also properties of erodible material e.g. microstructure, hardness or Young modulus. In order to reduce the negative impact of erosion on machine components, there are many methods to increase cavitation erosion resistance. The paper discusses the correlations between structural and mechanical properties and the resistance to cavitation erosion (CER) of pure materials, their alloys and coatings. Methods to increase CER have also been described - using heat / thermo-chemical treatment and application of coatings by various methods.

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Elastostatic Analysis of the Spatial FGM Structures

-425. [39] Murin, J., Aminbaghai M., Kutis, V. Exact solution of the bending vibration problem of the FGM beam with variation of material properties. Engineering Structures (2010) 32: 1631-1640. [40] Aminbaghai, M., Murin, J., Kutis V. Modal analysis of the FGM-beams with continuous transversal symmetric and longitudinal variation of material properties with effect of large axial force. Engineering Structures (2012)34: 314-329. [41] Murin, J., Aminbaghai, M., Kutis, V., Hrabovsky, J. Modal analysis of the FGM beams with effect of axial

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Seismic Material Properties of Reinforced Concrete and Steel Casing Composite Concrete in Elevated Pile-Group Foundation

Abstract

The paper focuses on the material mechanics properties of reinforced concrete and steel casing composite concrete under pseudo-static loads and their application in structure. Although elevated pile-group foundation is widely used in bridge, port and ocean engineering, the seismic performance of this type of foundation still need further study. Four scale-specimens of the elevated pile-group foundation were manufactured by these two kinds of concrete and seismic performance characteristic of each specimen were compared. Meanwhile, the special soil box was designed and built to consider soil-pile-superstructure interaction. According to the test result, the peak strength of strengthening specimens is about 1.77 times of the others and the ultimate displacement is 1.66 times of the RC specimens. Additionally, the dissipated hysteric energy capability of strengthening specimens is more than 2.15 times of the others as the equivalent viscous damping ratio is reduced by 50%. The pinching effect of first two specimens is more obvious than latter two specimens and the hysteretic loops of reinforced specimens are more plumpness. The pseudo-static tests also provided the data to quantitatively assessment the positive effect of steel casing composite concrete in aseismatic design of bridge.

Open access
Non-Destructive Technique for Determination of Elastic Material Properties

References [1] R. F. Gibson, “Modal Vibration Response Measurements for Characterization of Composite Materials and Structures,” Composite Science and Technology , vol. 60, pp. 2769-2780, 2000. [2] C. M., Mota Soares, M. Mreira de Freitas, A. L. Araujo, Identification of Material Properties of Composite Plate Specimens,” Composite Structures , vol. 25, pp. 277-285, 1993. [3] P. S. Frederiksen, “Experimental Procedure and Results for the identification of Elastic Constants of Thick Orthotropic Plates

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Estimating Design Resistance of Wrought Balcony Girders

. Introduction to Probability and Statistics for Engineers. Berlin : Springer-Verlag, 2013. 181 pp. ISBN 978-3-642-38299-4. [11] KÜHN, B., HELMERICH, R., NUSSBAUMER, A. et al. Assessment of existing steel structures: recommendations for estimation of remaining fatigue life. JRC, 2007. 89 pp. ISBN 1018-5593. [12] JUNG, K., MARKOVA, J., POKORNY, P. & SYKORA, M. Material Properties of Heritage Wrought Steel Structure Based on In-Situ Tests (accepted for publication). In Proc. STREMAH 2017. Ashurst Lodge : WIT Press, 2017. [13] HOLOWATY, J.M. & WICHTOWSKI, B

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Estimation of Material Properties of Carbon Nanotubes Using Finite Element Method

Abstract

The paper deals with estimation of material properties of single-walled carbon nanotubes (SWCNTs). The SWCNTs are simulated as frames, where carbon atoms are replaced by nodes and interatomic interactions are replaced by beams. The tension and torsion loading is applied on SWCNTs for determining the elastic modulus, Poisson’s ratio, shear modulus and membrane stiffness of SWCNTs. The simulations for obtaining elongations and torsion angles of SWCNTs are accomplished by the finite element method.

Open access