Key Engineering Materials Vols. 474-476

Abstract: When do research on the location of partial discharge in power generator’s stator using ultrasonic sensor, there are many problems exist including that ultrasonic signals detection is not obvious or even ultrasonic sensor can not detect ultrasonic signals. This article researches the location distribution in power generator which is favorable for ultrasonic sensor to receive ultrasonic signals. Put forward a placement method of sensor which is applies to the partial discharge location of power generator basing on sonic pressure distribution of ultrasonic signal in the stator’s outer, which is obtained by simulating sound field of power generator stator using ANSYS Multiphysics. The placement method of sensor has laid the foundation for the future research of the partial discharge location of power generator. Through comparing the simulation results and actual experimental test, the authors find that simulation of sonic pressure is similar to experimental results, proving the placement method is validity.

Abstract: The geological body has uncertainty and complexity characters, therefore the predesign scheme for construction has blindness. Field measurement and back analysis can help identify rock mass parameters in actual engineering field. The paper combines an intelligent optimization arithmetic-particle swarm optimization (PSO) and 3-D fast Lagrange numerical method to construct a parameters back analysis method for underground engineering. The PSO has global robust optimization property and overcomes the conventional optimization method problem of being limited in local optimization. The FISH language is used to develop the PSO arithmetic and is embedded in the business software- FLAC-3D. The method is used in Dalian Metro construction and it proves that this method has not only fast convergence speed but also high prediction. It offers a new idea to geotechnical parameters identification.

Abstract: This study aims to investigate and compare the influence of plantar loading variables during gait of patients with diabetic in young ages. Subjects were divided into the following two groups: diabetic foot, 56 subjects; control group, 52 subjects. Plantar pressure distribution was measured during barefoot gait using the Novel emed platform. Both midfoot and lateral forefoot regions’ peak pressure in the diabetic foot was higher than the normal foot. Also, diabetic foot group experienced significantly higher in pressure-time integral and contact time. Those variables provided an indication of plantar loading behavior over time, and other kinesiological factors like joint deformities and mobility can be investigated in further study.

Abstract: Using the general digital phase transformer is unable to measure the minimum phase of the mutual inductor. This paper introduced the basic principles of using an oscilloscope to measure the minimum phase of the mutual inductor. It gives a measurement method and the steps. It has certain significance to small precision measurement phase transformer.

Abstract: The effects of chlorine on improving hydrogen diffusion have been studied by first principle calculations and we obtain the diffusivity of hydrogen in liquid aluminum which is in agreement with the experimental data. It can be concluded that the diffusion of hydrogen in aluminum melts can be enhanced in the presence of chlorine and mobility of aluminum is depressed by forming alumina layer which can impede the diffusion of hydrogen.

Abstract: Passive location system does not radiate electromagnetic wave, so it can work passively and conceal itself very well. Main factors interfering location precision are: measure errors of time difference, measure errors of three satellites, height errors of targets location on earth, geometry form of satellites cluster and orbit height of satellites cluster; The Least-square estimation method is presented, at the same time in the process of algorithm iteration the target height can be inquired in the geography information system and be corrected continuously, and the localization error is analyzed and simulated, the result indicates that the corrected height error can improve the height precision, then improve the level precision, The integral localization precision can be improved.

Abstract: Based on the theory of the current economic evaluation of the highway construction projects, the author makes clear and demonstrates the computer program processing and the principle of designing the models of the Economic Evaluation System of the Highway Construction Projects in this paper, and concisely introduces the clew to design the system, the constitutes and functions of the system and the key technology. Finally, the author designs the computer implementation program taking the computation of economic evaluation internal returns ratio target as the example, and carries on the confirmation by the project example computation.

Abstract: The finite element analysis is presented in this paper in order to investigate the influence of interphase properties on restored-tooth structure due to polymerization shrinkage of resin-based composite. The restoration-tooth interface is simulated using plane elements of varying material properties and thicknesses. The stress and displacement within restored-tooth structure built-up from the polymerization shrinkage of the restorative composite were computed accounting for the time-dependent, visco-elastic behaviour of the composite. It was found that a correlation exists between material and geometry properties at the restoration-tooth interface and higher shrinkage stresses on interphase due to polymerization shrinkage. The development trend of residual stress from polymerization shrinkage in the restored-tooth structure was discussed and forecasted.

Abstract: Traditional time-frequency analysis methods such as short-time Fourier transform (STFT) and Wigner-Ville distribution (WVD) cannot always work effectively for the complex rotor systems where the multiple faults are involved. A noise cancellation method for the rotor faults detection is proposed in this paper by combining the independent component analysis (ICA) scheme and the adaptive time-frequency analysis (ATFA) approach. In the proposed method, the raw picked data are first separated into different independent components (ICs) via the ICA according to the different vibration sources. Then the ICs are processed by the ATFA to obtain a clear vibration character for the fault diagnosis. Experiments on a rotor system with hybrid fault of the rotor imbalance and the bolt looseness are introduced to verify the feasibility and validity of the proposed scheme.

Abstract: Single-piece-small-batches are typical in electric cabinet company. It results in huge BOM (bill of material) data. The article analyzes the product processes in electric cabinet company and presents BOM architecture. It is consist of design BOM, parameter BOM, manufacturing BOM, purchasing BOM and cost BOM, which simplifies BOM management and storage. BOM is denoted as weight number tree. Tuples are put forward to express the tree and the structure is converted to relational database storage. It is applied to express node query and checksum algorithms with structure query language, which proves the tuples maintainability. On this basis, BOM management system is established. Enterprise applications show that a feasible plan for electric cabinet company BOM management is presented.