Papers by Keyword: Fault

Abstract: Offshore platforms are used worldwide for drrilling, proceesing and even storage purposes. The offshore platforms can be fixed to the seabed, or can be float. The fixed platform namely jacket structure is a complex construction and design. Construction process of the jacket structure sometimes is not in accordance with the time schedule. There are many factors affect them, limited time, equipment, materials required, and cost of human resources. In order to analyze the delay factors of a jacket project requires a systematic approach. This paper will discusses the delay factors of the construction of Jacket Structure using FTA (Fault Tree Analysis). Data is obtained from one fabrication company which involve their experts to identify the contribution of delay project. There are three main factors causing the Jacket project delay namely Long Process of Procurement, Late Schecule of Assembly Structure, and Bad Management.

Abstract: There is a potential for major damage to the pipelines crossing faults, therefore the strain-based design method is essential for the design of buried pipelines. Finite element models based on soil springs which are able to accurately predict pipelines’ responses to such faulting are recommended by some international guidelines. In this paper, a comparative analysis was carried out among four widely used models (beam element model; shell element model with fixed boundary; shell element model with beam coupled; shell element model with equivalent boundary) in two aspects: differences of results and the efficiency of calculation. The results show that the maximum and minimum strains of models coincided with each other under allowable strain and the calculation efficiency of beam element model was the highest. Besides, the shell element model with beam coupled or equivalent boundary provided the reasonable results and the calculation efficiency of them were higher than the one with fixed boundary. In addition, shell element model with beam coupled had a broader applicability.

Abstract: SDH transmission mode is a new concept of digital transmission. SDH transmission network can not only improve the efficiency of network management, and can greatly improve the utilization of network resources, reduce the management cost and maintenance cost, to ensure that the network operation and maintenance is flexible operation, reliable and efficient. Social and economic development promotes the development of railway transportation in our country, and the combined railway transportation with communication technology, making up a highly digital railway communication network. In the railway communication network, most of which the transmission technology of SDH transmission network has been adopted. SDH transmission network plays an important role in railway communication network.

Abstract: Fan occupies the important position in many industry, it give rise to that fault diagnosis become the new hot research topic, also is the urgent demand of many manufacturing enterprises. This paper based on the theory of wavelet packet transform, selecting wavelet packet transform and energy spectrum to wavelet de-noising and fault feature extraction the fan vibration signal. And use the MATLAB get the fan vibration signal characteristic vector, lay the foundation for the fan fault diagnosis.

Abstract: The current feature for motor carried with natural mixed eccentric and bearing fault is merely focused even though it is very important for motor online diagnosis. Based on the amplitude modulation, this theme researched on periodic change of the air-gap length caused by not only bearing fault but also mixed eccentric. Based on the relationship between the motor inductance and the magnetic permeability, the inductance expression was deduced for motor with bearing fault, motor with mixed eccentric and motor with not only bearing fault but also mixed eccentric. A new current eigenfrequencies expression was introduced by employing proposed inductance expression. Finally, a series of simulation studies were conducted, the results show that the new current eigenfrequencies expression is valid and useful for online diagnosis of those motor in service.

Abstract: While high steel grade X70, X80 pipeline has been widely used in long-distance oil and gas pipeline engineering of China, to further improve steel grade to X90 is an effective way to increase the efficiency of pipeline transportation and reduce construction cost. In this paper, the failure probability of earthquake fault crossing of X90 pipeline has been calculated with the strain-based reliability design method and the design scheme has been adjusted according to sensitivity analysis with influence factors of the failure probability of fault-crossing of X90 pipeline, after that the scheme of fault-crossing of X90 pipeline which meets requirements of pipeline reliability has been figured out. This study has laid a theoretical foundation for the application of X90 pipeline in future construction of pipeline engineering.

Abstract: Vehicle is a complicated mechanical system. Its fault often caused by the interactions between the hidden deep reason and multiple systems. Our work is form the electronic engine diagnosis reasoning knowledge to solve the problems of such faults. In order to make fault process and fault concept clearly, constraint relation and causal chain between fault and symptom are introduced. Problems solved including the binding interaction between ontologies, transfer process from the failure to of the final symptom, and inference rules of reasoning rules.

Abstract: This paper introduces the broken shaft failure problem of vacuum pump often encountered, and through the failure mechanism analysis of broken shaft in several aspects, the paper not only summarizes the cause of broken shaft vacuum pump, which is found in five main aspects of broken shaft vacuum p

Abstract: Diagnosis of engine fault is critical in reducing maintenance costs. A new method which incorporates hybrid relative vector machines and genetic algorithm (RVM-GA) was proposed to predict aero engine fault based on data of the spectrometric oil analysis. Experimental results show that it has a high accuracy and effective properties.

Abstract: Explain the existing device to avoid reeling cocoon sinking in automatic silk reeling machine, research the prevention of cocoon sinking automatically, and provide the integrated solution to keep cocoons in arrangement for reeling. In general, stop motion rod sends a signal when a minor fault occurs in each end, takes the initiative to prevent fault spread to knotty fault which causes a series of bad effects. Then coordinate with interlocked equilibrium, through end feeding cam to control separating plate, ensure the process safe in the most economical way for the industrial market demand. Operators need not handle the system manually while treating the faults, then removing hidden trouble and raising labor efficiency, so higher grade raw silk can be produced. This technique used can improve machine performances, it is the basis on which silk reeling machine should continue to develop.