The present paper develops a new method for damage localization and severity estimation based on the employment of modal strain energy. This method is able to determine the damage locations and estimate their severiti...The present paper develops a new method for damage localization and severity estimation based on the employment of modal strain energy. This method is able to determine the damage locations and estimate their severities, requiring only the information about the changes of a few lower natural frequencies. First, a damage quantification method is formulated and iterative approach is adopted for determining the damage extent. Then a damage localization algorithm is proposed, in which a damage indicator is formulated where unity value corresponds to the true damage scenario. Finally, numerical studies and model tests are conducted to demonstrate the effectiveness of the developed algorithm.展开更多
Core damage accident scenarios are identified for the metal-fueled, sodium-cooled fast reactor （SFR）, KALIMER-600, which is under development at KAERI. A level 1 probabilistic safety assessment （PSA） model is deve...Core damage accident scenarios are identified for the metal-fueled, sodium-cooled fast reactor （SFR）, KALIMER-600, which is under development at KAERI. A level 1 probabilistic safety assessment （PSA） model is developed using the identified accident scenarios and the system fault tree models for the safety systems which are needed to mitigate the accidents. Using the preliminary level 1 PSA models, core damage frequency is estimated for the metal fueled KALIMER-600 conceptual design. Sensitivity studies for various design alternatives of safety systems are performed to find out optimal configurations in point of view of risk minimization.展开更多
The significance of studying, monitoring and predicting blast induced vibration and noise level in mining and civil activities is justified in the capability of imposing damages, sense of uncertainty due to negative p...The significance of studying, monitoring and predicting blast induced vibration and noise level in mining and civil activities is justified in the capability of imposing damages, sense of uncertainty due to negative psychological impacts on involved personnel and also judicial complaints of local inhabitants in the nearby area. This paper presents achieved results during an investigation carried out at Sungun Copper Mine, lran. Besides, the research also studied the significance of blast induced ground vibration and air- blast on safety aspects of nearby structures, potential risks, frequency analysis, and human response. According to the United States Bureau of Mines （USBM） standard, the attenuation equations were devel- oped using field records. A general frequency analysis and risk evaluation revealed that： 94% of generated frequencies are less than 14 Hz which is within the natural frequency of structures that increases risk of damage. At the end, studies of human response showed destructive effects of the phenomena by ranging between 2.54 and 25.40 mm/s for ground vibrations and by the average value of 110 dB for noise levels which could increase sense of uncertainty among involved employees.展开更多
基金supported by the National Natural Science Foundation of China (50909088, 51010009)Science & Technology Development Project of Qingdao (09-1-3-18-jch)Program for New Century Excellent Talents in University (NCET-10-0762)
文摘The present paper develops a new method for damage localization and severity estimation based on the employment of modal strain energy. This method is able to determine the damage locations and estimate their severities, requiring only the information about the changes of a few lower natural frequencies. First, a damage quantification method is formulated and iterative approach is adopted for determining the damage extent. Then a damage localization algorithm is proposed, in which a damage indicator is formulated where unity value corresponds to the true damage scenario. Finally, numerical studies and model tests are conducted to demonstrate the effectiveness of the developed algorithm.
文摘Core damage accident scenarios are identified for the metal-fueled, sodium-cooled fast reactor （SFR）, KALIMER-600, which is under development at KAERI. A level 1 probabilistic safety assessment （PSA） model is developed using the identified accident scenarios and the system fault tree models for the safety systems which are needed to mitigate the accidents. Using the preliminary level 1 PSA models, core damage frequency is estimated for the metal fueled KALIMER-600 conceptual design. Sensitivity studies for various design alternatives of safety systems are performed to find out optimal configurations in point of view of risk minimization.
文摘The significance of studying, monitoring and predicting blast induced vibration and noise level in mining and civil activities is justified in the capability of imposing damages, sense of uncertainty due to negative psychological impacts on involved personnel and also judicial complaints of local inhabitants in the nearby area. This paper presents achieved results during an investigation carried out at Sungun Copper Mine, lran. Besides, the research also studied the significance of blast induced ground vibration and air- blast on safety aspects of nearby structures, potential risks, frequency analysis, and human response. According to the United States Bureau of Mines （USBM） standard, the attenuation equations were devel- oped using field records. A general frequency analysis and risk evaluation revealed that： 94% of generated frequencies are less than 14 Hz which is within the natural frequency of structures that increases risk of damage. At the end, studies of human response showed destructive effects of the phenomena by ranging between 2.54 and 25.40 mm/s for ground vibrations and by the average value of 110 dB for noise levels which could increase sense of uncertainty among involved employees.
