International Journal of Applied Electromagnetics and Mechanics - Volume 33, issue 3-4

Authors: Ma, Youli

Article Type: Research Article

Abstract: Testing for bending fatigue crack propagation under mixed-mode condition was carried out using fatigue and annealed slant pre-cracks with different slant angles, β, defined as the angle between loading and crack directions in a rectangular plate. As a result, bending fatigue crack from the fatigue pre-crack with β=45 deg propagated under mixed-mode condition with mode I and II stress intensity factors K_{I} and K_{II} , while bending fatigue cracks …from the fatigue pre-crack of β=60 deg and from the annealed pre-cracks with both slant angles of β=60 deg and β=45 deg propagated under mode I crack behavior. Furthermore, the estimated fracture angles calculated by maximum tangential criterion using the stress intensity factors, K_{I} and K_{II} , are in good agreement with the measurement ones except the fatigue pre-crack of β=45 deg at the initial premium propagation. That is to say fatigue crack propagation behavior was effected by compressive residual stress around pre-crack while the slant angle β is smaller (such as β=45 deg in this study). But the effect was disappeared if β became bigger (such as β= 60 deg.). Show more

Keywords: Mixed-mode, compressive residual stress, bent fatigue crack, fatigue crack propagation, crack discontinuous displacement, fatigue pre-crack, annealed pre-crack

DOI: 10.3233/JAE-2010-1287

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1579-1585, 2010

Authors: Yusa, Noritaka | Miya, Kenzo | Komura, Ichiro | Chen, Zhenmao

Article Type: Research Article

Abstract: This paper introduces a research project the authors have proposed. The project aims to gather non-destructive testing data of stress corrosion cracking specimens and present them as benchmark data freely available to researchers in the field. Round-robin test using seven austenitic stainless steel plate specimens with artificial stress corrosion cracking is carried out, and they are measured using various non-destructive testing methods. The data measured are made available together with the results of destructive tests to …confirm the true profile of the cracking. Show more

Keywords: Nondestructive testing, round-robin test, benchmark data, austenitic stainless steel

DOI: 10.3233/JAE-2010-1288

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1587-1590, 2010

Authors: Liu, Liqiang | Luo, Xianjue | Niu, Tao

Article Type: Research Article

Abstract: In China, the serious accidents due to severe corrosion of substation's grounding grid often take place. To better analyze results of corrosion diagnosis for grounding grids, a novel approach to creditability analysis by means of testability matrix factorization was presented. A new testability matrix was derived, which has only to do with topological structure and test information without any partial derivative operation, and then nonlinear diagnostic equations were established. The branch ambiguity groups …and the set of surely testable branches were obtained through the testability matrix by Gauss-Jordan elimination method. The example of simulation shows that the results of the surely testable components are changeless in different diagnosis under fully tested conditions. It points out that misdiagnosis is inevitably due to the existence of ambiguity groups. Show more

Keywords: Grounding grid, corrosion diagnosis, testability matrix

DOI: 10.3233/JAE-2010-1289

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1591-1597, 2010

Authors: Chady, Tomasz | Lopato, Przemyslaw

Article Type: Research Article

Abstract: Terahertz electromagnetic waves become a very useful tool for nondestructive testing of glass-fiber reinforced composite materials. In this paper we deal with detection abilities of defects which may arise in the mentioned structures. Terahertz time domain measurements enable us to gain an information about interior part of multilayered materials. In order to flaws detectability evaluation finite element method simulations were carried out. Numerical analysis was verified by measurements of multilayered reference structures.

Keywords: THz waves time domain measurements, composite materials, THz wave propagation numerical modeling

DOI: 10.3233/JAE-2010-1290

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1599-1605, 2010

Authors: Wang, Zhenqing | Qiao, Mu | Han, Yulai | Zhu, Dalei

Article Type: Research Article

Abstract: For the large deterioration of the mechanical properties of steel under high temperature, the resistance of steel members will be largely discounted. The calculations of yield strength and Young's modulus of steel under high temperature recommended by ECCS have been employed in this paper. A simple and feasible time-variant model of the resistance of steel members and a reliability index analysis method of steel structure under fire has been given. An example, which illustrates the action …of ISO834 temperature rising curve on the time-variant reliability index of a steel beam have presented. The results showed that the reliability index of a steel beam decreased with the increasing of the fire action time. When the time of fire action exceeds 138 minutes, the reliability index of a steel beam is less than the minimum value stipulated by the norm. Show more

DOI: 10.3233/JAE-2010-1291

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1607-1613, 2010

Authors: Chady, Tomasz | Napierala, Lech | Baniukiewicz, Piotr | Sikora, Ryszard

Article Type: Research Article

Abstract: In this paper a dedicated approach to detection of casting abnormalities on radiogram images is discussed. The case was studied on a specific example of impeller blades and it was shown, that certain features of those blades make approximation approach a natural choice. A method of computation acceleration was also discussed.

Keywords: nondestructive testing, maintanance and reliability, image processing

DOI: 10.3233/JAE-2010-1292

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1615-1621, 2010

Authors: Ba, Ying | Zhang, Li | Cheng, Jin

Article Type: Research Article

Abstract: A new simple two-parameter multi-axial fatigue failure criterion is proposed, which is focused on the engineering application. The proposed multi-axial fatigue failure criterion is based on shear strain and normal strain, and then focused on cycling additional hardening normal stress is selected to replace normal strain. The damage degree is assumed to be linearly accumulated. The larger one of the two parameters determined the orientation of critical pane, and the linear combination of the two parameters …is considered to be simple and convenient to predict fatigue life. Show more

Keywords: Low-cycle fatigue, fatigue damage accumulation, critical plane approach, two parameter

DOI: 10.3233/JAE-2010-1293

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1623-1628, 2010

Authors: Tsutsui, Atsushi | Miki, Hiroyuki | Takeno, Takanori | Takagi, Toshiyuki

Article Type: Research Article

Abstract: CVD diamond films are expected to become maintenance-free solid lubricant coatings. However, substrates on which diamond film can be deposited have been limited to materials such as silicon and tungsten carbides. If diamond films can be deposited onto steel substrates, it will increase the number of possible applications. Diamond film was deposited on a steel substrate with an interlayer and was partly polished. Tungsten and titanium were selected as materials for the interlayer between diamond film …and AISI 440C steel substrate. Low and stable friction coefficients were obtained between diamond film and AISI D2 pin, with friction coefficient 0.1 in the steady-state regime. Show more

Keywords: Diamond film, Friction, Interlayer, Stainless steel

DOI: 10.3233/JAE-2010-1294

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1629-1634, 2010

Authors: An, Qun-Tao | Sun, Li | Zhao, Ke | Sun, Li-Zhi

Article Type: Research Article

Abstract: The reliability of PWM inverters is direct related to the safety of motor drive systems. Three-phase four-switch inverter (TPFSI) as a fault-tolerant topology is studied and space vector pulse width modulation (SVPWM) for TPFSI is investigated in this paper. The essence of four-switch SVPWM (FS-SVPWM) is revealed. In order to improve the utilization rate of the DC link voltage, a compensatory voltage vector based over-modulation method for FS-SVPWM is proposed. The simulation and experimental results validate …the proposed algorithm. Show more

Keywords: Four-switch inverter, fault-tolerant, SVPWM, over-modulation

DOI: 10.3233/JAE-2010-1295

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1635-1642, 2010

Authors: Tokida, Kenichiro | Takemura, Kenjiro | Yokota, Shinichi | Edamura, Kazuya

Article Type: Research Article

Abstract: This study develops a novel robotic earthworm using electro-conjugate fluid (ECF), which generates a jet flow with high DC voltage. The robot, inside of which is filled up with ECF, has two ECF jet generators sandwiched with three flexible silicone rubber tubes (all components are located in series). When applying an appropriate electrical input to each jet generator, the robot generates a peristaltic motion, which may push the body forward. The robot is 60 mm long …with the diameter of 6 mm. The experimental results confirm the robot moves in a � 6.5 mm acrylic resin pipe with 0.13 mm/s. Show more

DOI: 10.3233/JAE-2010-1296

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1643-1651, 2010