[en] Reliability is a key concern of all machines that must maintain good operating conditions. There are many mechanisms of damage that lead to the failure of the system. In this presentation, the tribological approach to performing accelerated wear test of mechanical components is discussed. In order to accelerate the wear effect the mechanism of wear must first be understood. The mechanisms of wear for various applications are presented. Also, the use of Stribeck curve and Archard's wear equation in determining the acceleration parameters are proposed. By selecting the proper speed, load, and lubrication condition in the wear test, the failure due to wear can be accelerated

[en] Time reversal (TR) of nondispersive body waves has been used in many applications including ultrasonic NDE. However, the study of the TR method for Lamb waves on thin structures is not well established. In this paper, the full reconstruction of the input signal is investigated for dispersive Lamb waves by introducing a time reversal operator based on the Mindlin plate theory. A broadband and a narrowband input waveform are employed to reconstruct the A₀ mode of Lamb wave propagations. Due to the frequency dependence of the TR process of Lamb waves, different frequency components of the broadband excitation are scaled differently during the time reversal process and the original input signal cannot be fully restored. This is the primary reason for using a narrowband excitation to enhance the flaw detectability

[en] A new laser-based ultrasonic receiver that is based on multi-channel interferometry is shown to be well suited for robust and sensitive detection of ultrasound in industrial environment. The proposed architecture combines random-quadrature detection with detector arrays and parallel multi-speckle processing. The high sensitivity is reached, thanks to the random phase distribution of laser speckle caused by surface roughness. High-density parallel signal processing is achieved by using a simple demodulation technique based on signal rectification. This simple detection scheme is also demonstrated for rejection of the laser intensity noise, making possible the use of lower cost laser without reduction in performances. Results demonstrating this new principle of operation and its performances are presented

[en] The European methodology for qualification of non-destructive testing is a well-established approach adopted by nuclear utilities in many European countries. According to this methodology, qualification is based on a combination of technical justification and practical trials. The methodology is qualitative in nature, and it does not give explicit guidance on how the evidence from the technical justification and results from trials should be weighted. A Bayesian model for the quantification process was presented in a previous paper, proposing a way to combine the 'soft' evidence contained in a technical justification with the 'hard' evidence obtained from practical trials. This paper describes the results of a pilot study in which such a Bayesian model was applied to two realistic Qualification Dossiers by experienced NDT qualification specialists. At the end of the study, recommendations were made and a set of guidelines was developed for the application of the Bayesian model.

[en] Advancements in the imaging and computing technology have opened the path to digital holography for non-destructive investigations of technical samples, material property measurement, vibration analysis, flow visualization and stress analysis in aerospace industry which has widened the application of digital holography in the above fields. In this paper, we demonstrate the non-destructive investigation and micro-structure measurement application of digital holography to the small particles and a biological sample. This paper gives a brief description of the digital holograms recorded with this system and illustratively demonstrated

No abstract available

[en] Many forces are pressuring utilities to reduce operating and maintenance costs without cutting back on reliability or availability. Many utility managers are re-evaluating maintenance strategies to meet these demands. To utilities how to reduce maintenance costs and extent the effective operating life of equipment, predictive maintenance technique can be adapted. Predictive maintenance had three types program which are in-house program, engineering company program and mixed program. We can approach successful predictive maintenance program with 'smart trust' concept

[en] Recently, portable magnetic sensors with high sensitivity are strongly required for various applications such as biosensor, nondestructive testing and directional sensor. A novel magnetic sensor system was developed by utilizing giant magnetoimpedance(MI) effect of soft magnetic ribbons. The sensor system consists of sensing head of CO₆₆Fe₄Si₁₅B₁₅ ribbon having asymmetric MI characteristics through exchange coupling produced by field-annealing in open air and circuit for signal processing. The sensor system showed almost linear characteristics in dynamic range of -1Oe ∼ 1Oe and sensitivity of 10.5 V/Oe. The sensor was applicable to nondestructive testing system to detect defects in wire ropes.

[en] Many one shot devices are kept in storage and taken into use when required. This paper examines the deterioration of the devices when in storage. For a complex device limited non-destructive testing and repair is possible short of using it in a destructive test. The tests are not perfect and can give false positive and false negative results. When a fault is indicated a minimal repair is carried out. The objective is to establish levels of reliability of individual components which together with the inspection regime give a particular level of reliability in the delivered components. Assuming a general distribution for the time to fail in storage the likelihood is developed and used to estimate the parameters of the model. The estimated model can then be used to explore different inspection and repair policies

[en] Phononic crystals are the acoustic wave analogue of photonic crystals. Here a periodic array of scattering inclusions located in a homogeneous host material forbids certain ranges of acoustic frequencies from existence within the crystal, thus creating what are known as acoustic bandgaps. The majority of previously reported phononic crystal devices have been constructed by hand, assembling scattering inclusions in a viscoelastic medium, predominantly air, water or epoxy, resulting in large structures limited to frequencies below 1 MHz. Recently, phononic crystals and devices have been scaled to VHF (30–300 MHz) frequencies and beyond by utilizing microfabrication and micromachining technologies. This paper reviews recent developments in the area of micro-phononic crystals including design techniques, material considerations, microfabrication processes, characterization methods and reported device structures. Micro-phononic crystal devices realized in low-loss solid materials are emphasized along with their potential application in radio frequency communications and acoustic imaging for medical ultrasound and nondestructive testing. The reported advances in batch micro-phononic crystal fabrication and simplified testing promise not only the deployment of phononic crystals in a number of commercial applications but also greater experimentation on a wide variety of phononic crystal structures. (topical review)