ALBERT

Notes: The samples of Cz Si were subjected to multi-step annealing at different temperatures. After high temperature consequent steps the dislocation related spectra (DRL) were detected from the samples. The main feature of the DRL spectra was the very narrow low energy bands D1/D2, which are unusual for Cz Si. TEM analysis shown that the only candidates for DRL spectra are dislocation loops, punched out from precipitates. To explain the absence of influence of oxygen it was assumed that the distribution of interstitial oxygen is nonuniform in such samples and has some depletion regions in the vicinity of precipitates

Notes: In ASME Sec. III ‘design by analysis’ approach, stresses are generally calculated by finite element method and compared to corresponding stress limits after categorizing those components. However, in order to obtain optimum results, time consuming and expensive manipulations are required owing to its mesh size dependency and complicate stress categorization. In this paper, a newapproach based on structural stress is proposed to resolve the issues and applied to a heat exchanger motor operated valve. At first, the technical bases and specific features of structural stress approach are briefly discussed. Secondly a series of finite element analyses are carried out to show the limitations of current ASME approaches and to get basic data for the proposed approach. Finally, astructural stress concentration factor of motor operated valve is determined after comparison of local stresses and structural stresses, and utilized for fatigue life evaluation. Since the results show a promising applicability, it seems that the structural stress based approach can be utilized for fatigue life evaluation of components with complex geometries

Notes: The reactor vessel body and closure head are fastened with the stud bolt that is one of crucial parts for safety of the reactor vessels in nuclear power plants. It is reported that the stud bolt is often experienced by fatigue cracks initiated at threads. Stud bolts are inspected by the ultrasonic technique during the overhaul periodically for the prevention of failure which leads to radioactiveleakage from the nuclear reactor. The conventional ultrasonic inspection for stud bolts was mainly conducted by reflected echo method based on shadow effect. However, in this technique, there were numerous spurious signals reflected from every oblique surfaces of the thread. In this study, ultrasonic phased array technique was applied to investigate detectability of flaws in stud bolts andcharacteristics of ultrasonic images corresponding to different scanning methods, that is, sector and linear scan. For this purpose, simplified stud bolt specimens with artificial defects of various depths were prepared

Notes: The propagation characteristics of the back-reflected Rayleigh surface wave in chemical vapor deposit (CVD) diamond coated specimens were investigated experimentally using the ultrasonic backward radiation measurement. The deliberated delaminations produced between the coating layer and the substrate decreased Rayleigh surface wave velocity. This initial experimentalresult obtained in the present study demonstrates the high potential of the backward radiated ultrasound as a tool for nondestructive evaluation of very thin CVD diamond coating layer

Notes: The ADVENTURE project started as one of the research projects in the "Computational Science & Engineering" field selected for the "Research for the Future" Program sponsored by the Japan Society for the Promotion of Science during 1997-2002. Since March 2002, the project has continued as an independent project. In the project we have been developing an advanced general-purpose computational mechanics system, named ADVENTURE, running in various kindsof parallel and ditributed environments. The system is designed to be able to analyze a three-dimensional finite element model of arbitrary shape with 10-100 million DOFs mesh, and additionally to enable parametric and non-parametric shape optimization. The first version of the system has been released from the project website as open source software since March, 2002. 2,049 registered users in academia and industries have downloaded 12,827 modules and been using them,while one company has developed and released its commercial version named ADVENTUREcluster. The ADVENTURE system has been successfully implemented in various types of parallel and distributed environments including PC clusters, massively parallel processers such as Hitachi SR8000/MPP and the Earth Simulator, and Grid environments such as ITBL (IT-based Laboratory).The system has been successfully applied to solve various real world problems such as response of a full scale nuclear pressure vessel model and thermoelastic deformation of full scale electric mounting board of a mobile PC

Notes: During the last two decades, the interests of large scale seamless analysis have been increased with respect to lifetime extension and management of infra-structure. And then, a seamless analysis of complex geometry is one of greatly interesting topic. However, there are still gaps between the industrial applications and fundamental academic studies owing to time consuming the modeling and analyzing process. To resolve these problems, the integrity evaluation procedure from knowledge-based information system (KIS) to ADVENTRUE has been proposed for the application of auto mesh generation and large scale analysis. The virtual plant which is used for the master of KIS, provides the 3D information of entities for mesh generation. And then, the ADVENTURE makes a domain decomposed mesh and analyzes it using hierarchical domain decomposition method.Considering the good applicability in both efficiency and exactness point of views, it is anticipated that the proposed study on large scale analysis can be used as a promising integrity evaluation method of infra-structures

Notes: In this paper, eddy current signals from various anomalous defects in the steam generator tube are numerically predicted and their signal slope characteristics are investigated. The signal variations due to increased frequencies are also observed. Based on the accumulated knowledge, the analysis of compound signal is attempted which includes the effect of support plate. Both differential and absolute bobbin probe signals are analyzed. For the signal prediction, axisymmetric finite elementmodeling is used and this leads us to the utilization of slope angle analysis of the signal. Results show that differential signals are useful for locating the position of defect under the support plate, while absolute signals are easy to presume and interpret even though the effect of support plate is mixed. Combined use of these two types of signals will help us accomplish a more reliable inspection

Notes: The heavy load carrying facility, such as ladle crane, is operating under severe working environment. It usually carries melted iron to the furnace, and thus, the accident due to crane failure may cause detrimental damage to the entire steel making factory. While the ladle crane is designed for 20 years of safe operation in a steel making company, several critical cracks due to fatigue loadinghave been reported during the maintenance process. In order to prevent fatal failure due to crack growth, ladle crane has been periodically inspected and maintained. However, the inspection and maintenance including repair and replacement cause the whole manufacturing line to stop, it is critical to set the appropriate inspection interval and replacement criteria. For this reason, the importance ofplant maintenance (PM) has been highly raised to provide efficient plant operation. Recently, a number of engineering methodologies, such as fitness for service guidelines (FFS) and plant lifecycle management (PLM) system, have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP (Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there hasn’t been any attempt to connect engineering methodologies to the ERP PM(Plant Maintenance) system. In this paper, an engineering methodology which provides life time evaluation under fatigue loading has been implemented to the web-based ERP PM system along with real-time fatigue monitoring system. In order to monitor the real time loading, a web-based fatigue monitoring system for ladlecrane has been developed and installed inside the ladle crane. For the estimation of fatigue life, 3-dimensional finite element (FE) analyses were conducted for actual transients. Finally, the fatigue life time estimation program is developed by integrating FE analysis results and real-time monitoring data. For the direct calculation of remained fatigue life, an artificial neural network (ANN) algorithmhas been applied. The proposed system is expected to play a great role in determining appropriate inspection and maintenance schedule which has become critical issue for the efficient plant maintenance

Notes: The tribology of lubricated sliding vanes in the rotary compressor was investigated to replace the HFC refrigerants by the carbon dioxide. The carbon dioxide is a natural refrigerant and very favorable to environment. Because new compressors with the carbon dioxide are going to be operated under the high pressure, the tribology of sliding surfaces in the compressor becomes very important. To develop new compressors, especially rotary type, the friction and wear characteristicsof sliding surfaces between a vane and a roller in the rotary compressor were evaluated in this paper. Several hard coatings, such as TiN, CrN, WC/C and two types of nitridings, were applied on vane surfaces in order to improve the tribological characteristics, and their performances were evaluated experimentally. The vane-on-disk type sliding tests were carried out under the various sliding speeds,normal loads, and carbon dioxide pressures with an exclusive high pressure wear tester. From the tests wear volume of vane surfaces applied various coatings were compared. During the tests coefficients of friction and surface temperatures were monitored. Test results showed that WC/C coatings showed good tribological properties. TiN and CrN coated vanes showed good wear resistance properties but produced high friction