Papers by Keyword: Safety Assessment

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Authors: Ge Ning Xu, Fan Jiang
Abstract: By combined fuzzy comprehensive evaluation with AHP (Analytic Hierarchy Process) together, a safety assessment model for overhead traveling crane is set up in regard to deficiency of safety assessment method for crane at present, which can evaluate safety of overhead traveling crane in-service qualitatively and quantitatively. Through a safety analysis and assessment on general overhead traveling crane, the result of assessment is in accord with the practical situation of overhead traveling crane. It can reflect more fully the safety of the whole crane system and the influence and level of each factor to whole crane system safety, witch an effective synthetic evaluation method is put forward for the safety evaluation of crane.
Authors: Ge Ning Xu, Yu Peng Xin, Feng Yi Lu
Abstract: Aiming at security problem of metal structure of overhead traveling crane, the accident tree is established based on Accident Tree Analysis to further study. The solution of minimizing cut sets and least path sets are obtained by accident tree calculating. Finally several possible measures to prevent structural faults are obtained through final results of the calculation analysis.
Authors: Jong Duk Chung, Jang Sik Pyun
Abstract: Engineering safety diagnosis of crashed subway electric multiple units (EMUs) was conducted for safety assessment. Several advanced engineering analysis techniques including nondestructive evaluation (NDE) techniques and stress and structural analyses programs, were performed for better understandings and exploration of failure analysis and safety concerns. Moreover, stress and structural analyses using commercial I-DEAS software provided important information on stress distribution and load transfer mechanisms as well as the amount of damages during the crash. One-dimensional crashworthiness was conducted to estimate the speed at the time of the accident by investigating the permanent deformation of the train. The estimated speed was used as the input value of a three-dimensional crashworthiness analysis. A good agreement has been found between structural analysis results and the results of actual damages in EMUs during crash. In this investigation, various advanced engineering analysis techniques for the safety analysis of subway EMUs have been introduced and the analysis results have been used to provide the critical information for the safety assessment of crashed EMUs.
Authors: Yong Dan, Yi Han
Abstract: In this paper, the methods of the safety evaluation for thin-walled shells containing defects based on “Fitness for Service” principle were reviewed. The latest authoritative standards and codes for assessment in both domestic and international fields are introduced. The paper also proposes the existing problems in this field and discusses the main solutions of them. The innovation of the method and technical route mentioned in the resolvent are introduced at the same time. As a result, the trend of safety assessment method for thin-walled shell’s structure containing defects is prospected.
Authors: Toto Indriyanto, Hedi Hartalita
Abstract: Integrated avionics architectures offer advantages such as higher flexibility, reliability, simplicity, future upgradeability and weight saving over previous federated designs. Successful implementations of integrated modular avionics (IMA) are onboard Boeing B777, B787, Airbus A380 and A350. These applications often result in development and maintenance cost not suitable for regional and general aviation aircraft. One popular approach to overcome this problem is by using integrated flight deck (IFD) supplied by avionics manufacturers such as Garmin or Honeywell. These manufacturers often optimize IFDs for applications in developed countries. For example, with the development and widespread use of satellite-based global positioning system (GPS) in the US, Canada and Europe, some terrestrial navigation equipment (e.g. ADF and DME) are no longer included in the standard IFD packages offered for commercial aviation. However, many areas in the rest of the world still use and rely largely on the availability of the ADF, DME, etc. Aircraft flying in these areas need to comply with the local requirements for terrestrial navigation systems already deployed. In this paper a study on the implementation of additional avionics equipment on Garmin G1000 for advanced regional turboprop aircraft is presented. G1000 is an integrated avionics system that integrates many electronic components including navigation, communication, course, attitude, display, etc. It has been widely used in all kinds of civil aviation aircraft. In order to conform to local and modern requirements, ADF receiver, DME transceiver, traffic alerting system and weather radar need to be integrated. Preliminary reliability analysis using fault tree method is performed for the designs to ascertain their safety as set out in the requirements for advanced regional turboprop aircraft.
Authors: Tae Eun Jin, Heung Bae Park, Hho Jung Kim
Abstract: Kori Unit 1, which is the oldest nuclear power plant (NPP) in Korea has been operated since 1978. In addition, 10 other NPPs have been operating more than 10 years. As the number of aging plants rise, public concern over the safety of operating NPPs has increased. Periodic safety review (PSR) in addition to the existing safety assessments are proposed by IAEA as an effective way to verify that operating NPPs maintain the high level of safety. In this regard, the Ministry of Science and Technology (MOST), Korea’s nuclear regulatory body, recently established an institutional process through revision to the atomic energy act to introduce PSR. This PSR considers, among other factors, improvements in safety standards and practices, the cumulative effects of plant aging, operating experience, and the evolution of science and technology. In particular, the assessment and management of plant aging is one of the major areas. It includes identification of the system, structure and components (SSCs) for aging management, assessment of aging effects and planning of aging management implementation program. PSR results could be one of the procedural requirements that are utilized to renew an operating license of a NPP. This paper describes safety assessment requirements including PSR and aging management activities in Korea. This paper also includes the strategy and method for the application of PSR results to the aging management and continued operation of NPPs.
Authors: Jian Lan Zhou, Zhi Yu Sun, Da Wei Tang
Abstract: It is of great necessity to carry out safety assessment of high risk operations in hydroelectric projects. We analyze the key problems of safety assessment of high risk operations. Specifically, a questionnaire can be designed by applying the method of Failure Mode and Effects Analysis (FMEA) firstly; then the factors and consequences of risks in such operations can be generated by the questionnaire and interviews; further, the relationship among those factors can be determined based on statistical analysis, and a comparison matrix of Analytic Network Process can be constructed accordingly to verify and modify the model for safety assessment; finally, based on the outcome of safety assessment, the weak point in the hydroelectric project can be revealed and monitor, so that the safety of the project can be improved.
Authors: Ge Ning Xu, Wen Xiao Guo
Abstract: An index system for structure safety assessment was presented on the basis of analyzing and comparing of the domestic and foreign researchers. In addition, a method for structure safety measurement using Bayesian network, which has the excellent abilities of expressing and reasoning knowledge under uncertain environment, was proposed to construct a safety assessment model afterward. The assessment model is able to deal with complicated relationship as well as the different opinions of experts. The output of the safety assessment model can be used to predict and diagnose different safety conditions. Finally the model is applied to evaluate the security level of a certain overhead traveling crane.Its results show this method is effective and reasonable.
Authors: Zhi Xiang Duan, Kun Shi
Abstract: This paper discusses the plastic limit load of elbows without defects and with local thinned area (LTA) in the extrados under combined pressure and in-plane closing bending moment. Finite element analysis (FEA) and experiments have been used. The results of FEA show that, for the elbows without defects, when the ratio of pressure to the limit pressure (P/PL) is smaller than 0.469, the limit moment of elbows increases with the increasing pressure; when the ratio (P/PL) is bigger than 0.469, the limit moment of elbow decreases with the increasing pressure. For the elbows with LTA, the FEA results show that with different LTA the variation of the limit load of elbows to the pressure is different. Perhaps, the limit moment of elbows always decreases with the increasing pressure. It is also likely that the limit moment of elbows increases with the increasing pressure and then decreases with the increasing pressure. The results of FEA are consistent with the experimental results. By fitting the results of FEA, the safety assessment figure for elbows under combined pressure and in-plane closing bending moment is drawn.
Authors: Tao Huang, Guo Xin Zhang, Bo Yang, Lei Zhang
Abstract: The bonding problem of interface between the fresh and old concrete is one of the main technological difficulties in the Heightening Project of Danjiangkou Dam in the South-to-North Water Diversion Project. At present, no mature experiences or engineering examples are found in China for concrete dam heightening. Because of the external environmental impacts of temperature change, aging and hydraulic fracturing on the interface between the fresh and old concrete, crack is likely to occur, which brings risks to the safe operation of the dam. In this article, the finite element direct force method was used to calculate the internal force. The safety of No. 1 dam monolith was calculated in accordance with the standard method for gravity dam in three conditions of fresh-old concrete bonding interface, i.e., perfect condition, cracked interface and cracked interface with water seepage. Suggestions for their solutions were also provided.
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