Li Jicheng, Lin Li, Wu Di, Li Ximeng

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.2, pp. 43-44, 2011, DOI:10.3970/icces.2011.017.043

Abstract Two kinds of plasma sprayed Cr2O3 coating specimens are tested with electro-mechanical impedance (EMI) method. Quantitative investigation on the relationship between PZT excitation voltage and sensitivity of EMI method is performed in the frequency range of 100-110 kHz, with WK 6500B precision impedance analyzer and high excitation voltage electric impedance measurement system (HEVEIMS). A series of excitation voltage are designed from 0.01 to 15 V. Root mean square deviation (RMSD) of the PZT electric impedance signatures is used as an evaluation indicator. The results show that in the frequency range of 100-110 kHz, the RMSD More >

Lin Li, Li Jicheng, Wu Di, Li Ximeng

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.2, pp. 39-40, 2011, DOI:10.3970/icces.2011.017.039

Abstract Two kinds of plasma sprayed Cr2O3 coatings are tested with electro-mechanical impedance (EMI) method. The influence of frequency band on the testing sensitivity of EMI method is investigated in kHz and MHz frequency ranges. The frequency shifts and root mean square deviation (RMSD) of the PZT electric impedance signatures are used as evaluation indicator. The variation of EMI sensitivity is investigated on 8 frequency bands with high mode density in the frequency ranges of 0.1-600 kHz and 1-10 MHz. The results show that in the low frequency range, the frequency shifts increase and the RMSD More >

LIN Xiao-Ping, LEI Zhen-Kun, LIU Zeng-Hua, WU Zhan-Jun

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.1, pp. 29-30, 2011, DOI:10.3970/icces.2011.017.029

Abstract Recently, a technology named ultrasonic guided wave has a rapid development and wide application. It is more and more popular for the advantage compared with traditional detection. An enormous amount of work has contributed to our current understanding of wave propagation. The case of a hollow cylinder loaded by the outside liquid has been considered by Rose et al. Kwun investigated the propagation of guided waves in water filled pipes. C. Aristegui discussed propagation of guided waves in fluid-filled pipe surrounded by different fluids. Lafleur and Shields have studied the propagation of low frequency modes… More >

T. Fu, C.P. Wang, B. Hou, X.D. Zhu, Z.F. Zhou, K.Y. Li, J. Lu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.3, pp. 91-92, 2011, DOI:10.3970/icces.2011.020.091

Abstract Structural steels are widely used in engineering fields. Generally, they have the advantage of lower prices due to less precious alloy elements contained; however, their properties, especially the surface properties are inferior to high alloy steels. Surface engineering are of importance in improving surface properties of steels, and even a 'new' surface layer with high performances can be produced by surface technologies on low cost structural steels with ordinary properties.
The researches of last decade have shown that surface nanocrystallization (SNC) can markedly improve surface mechanical properties of metallic materials and accelerate thermal diffusion of N,… More >

Jianguo Zhu, Huimin Xie, Fulong Dai

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.1, pp. 3-4, 2011, DOI:10.3970/icces.2011.017.003

Abstract Thermal barrier coatings (TBCs) are widely used in turbines for propulsion and power generation. During build up the coatings, the continuity of the strain at the interface results in the residual stress because of the thermal expansion misfit. Since the formation of residual stresses cannot be avoided, they have to be optimized by adaptation of the process parameters during coating manufacturing. Therefore, in order to obtain information about the characterization of residual stresses for specific process conditions, the development of residual stress measurement is of vital importance.

In this paper, several techniques on residual stress More >

R. Ghelichi¹, S. Bagherifard¹, I. Fernandez Parienete², M.Guagliano^1,3, Simone Vezzù⁴

Structural Durability & Health Monitoring, Vol.6, No.1, pp. 17-30, 2010, DOI:10.3970/sdhm.2010.006.017

Abstract Coating deposition processes such as cold spraying are commonly employed to increase wear and fatigue resistance and consequently to enhance longevity of engineering components. Such processes typically introduce residual stresses into the coated surface, which in turn affect efficiency of coatings and play an important role in coating durability. In fact residual stresses are the key parameter to obtain compact and well-adherent coatings. They can modify several coating properties such as adhesion, structure, toughness, hardness reflecting on the macroscopic chemical and mechanical behavior of the coating.
Present study describes alteration of residual stress state of two More >

Taotao Hu¹, gping Shen^1,2

CMC-Computers, Materials & Continua, Vol.17, No.1, pp. 41-58, 2010, DOI:10.3970/cmc.2010.017.041

Abstract In this paper, an axisymmetric indentation model is set up to calculate the effects of the roughness of the thermally grown oxide (TGO) layer, which was modeled as a sinusoidal wave, on the indentation response of the thermal barrier coatings. It is found that the amplitude, wavelength, and thickness of the thermally grown oxide layer have obvious influences on the indentation response, while the effect of the indenter position can be neglected. In the top coating layer, residual stress mainly occurs below the indenter and around the nearest two peaks of the thermally grown oxide More >

C. Y. Chen¹, C. Atkinson²

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.3, pp. 219-240, 2009, DOI:10.3970/cmes.2009.048.219

Abstract In this paper, we extend our previous analysis of a contact problem with a circular indenter pressed normally against a semi-infinite elastic composite to that of a semi-infinite viscoelastic composite which consists of a contact layer with uniform thickness welded together with another dissimilar medium. Using the correspondence principle between the Laplace transformed elastic equations and the viscoelastic ones, the asymptotic results derived previously for the pure elastic case are readily adopted for the viscoelastic one with the elastic constants replaced by appropriate functions of Laplace transformed variables for the linear viscoelastic solid. We focus More >

Baolin Wang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.2, pp. 81-84, 2008, DOI:10.3970/icces.2008.008.081

Abstract When the size of a physical system is smaller than its characteristic dimensions, the macroscopic viewpoint may not be applicable. In addition, experiments at micro/nanometer scale are difficult and the analysis of nano-experimental data is far from simple. This is mostly due to the lack of effective models that are able to study the structural characteristics and mechanics behavior of the micro/nanometer physical systems. Atomic simulation simulation has been used extensively in the investigation of nanoscale phenomena. However, the size limit of atomic simulation is far short to reach the macroscale because of the limitation More >

T. Aizawa¹, H. Akebono², H.Suzuki¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.4, pp. 193-198, 2008, DOI:10.3970/icces.2008.005.193

Abstract In order to achieve power transmission parts like a compact gearwheel which indicates high performance properties, hybrid surface modification was performed by combining Super Rapid Induction Heating & Quenching(SRIQ) which creates high fatigue strength and Diamond Like Carbon (DLC) coating which are well known for their high hardness, low friction and excellent wear resistance. And, in order to prevent the base material from decreasing its fatigue strength, DLC was coated by using Unbalanced Magnetron Sputtering (UBMS) method which can coat at low temperature. Rotational bending fatigue tests and friction-wear tests were carried out. It was More >