Entity

Time filter

Source Type


Hong J.,Nanjing Southeast University | Hong J.,Key Laboratory of Concrete and Prestressed Concrete Structure | Rui X.-T.,Nanjing University of Science and Technology
Dandao Xuebao/Journal of Ballistics | Year: 2010

In order to obtain the mechanical property of propellant grain under low temperature and impact load, discrete element method was applied, and based on non-continuum medium, the fracture model of propellant grain was established. Fracture rule of propellant grain was the rule of Mohr-Coulomb. The fracture process of propellant grain impacting rigid wall with different velocities was simulated. The mechanical property of propellant grain under low temperature and impact load was qualitatively analyzed. The analysis result shows that the higher the impact velocity, the more serious the fracture of propellant grain is, and the result agrees with experiment. The method offers a new way for studying the fracture process of propellant grain. Source


Dang Y.,Key Laboratory of Concrete and Prestressed Concrete Structure | Dang Y.,Lanzhou University of Technology | Han J.-P.,Lanzhou University of Technology | Li Y.-T.,Lanzhou University of Technology
Computational Intelligence and Neuroscience | Year: 2015

This paper proposes an indicator of seismic performance based on life-cycle cost of a building. It is expressed as a ratio of lifetime damage loss to life-cycle cost and determines the seismic performance of isolated buildings. Major factors are considered, including uncertainty in hazard demand and structural capacity, initial costs, and expected loss during earthquakes. Thus, a high indicator value indicates poor building seismic performance. Moreover, random vibration analysis is conducted to measure structural reliability and evaluate the expected loss and life-cycle cost of isolated buildings. The expected loss of an actual, seven-story isolated hospital building is only 37% of that of a fixed-base building. Furthermore, the indicator of the structural seismic performance of the isolated building is much lower in value than that of the structural seismic performance of the fixed-base building. Therefore, isolated buildings are safer and less risky than fixed-base buildings. The indicator based on life-cycle cost assists owners and engineers in making investment decisions in consideration of structural design, construction, and expected loss. It also helps optimize the balance between building reliability and building investment. © 2015 Yu Dang et al. Source


Wang H.,Nanjing Southeast University | Wang H.,Key Laboratory of Concrete and Prestressed Concrete Structure | Li A.,Nanjing Southeast University | Li A.,Key Laboratory of Concrete and Prestressed Concrete Structure | And 2 more authors.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2010

Field measurement of buffeting response of long span bridges is of great significance to the development of bridge wind engineering. The Sutong Cable-stayed Bridge (SCB), as the longest cable-stayed bridge in the world, is taken as an example. When typhoon Fung-Wong passed through Jiangsu in July 2008, field measurement of the typhoon characteristics was conducted and the structural vibration responses were wholly recorded by the SHMS. Based on the frequency spectrum technique and statistical theory, the measurement data are analyzed to obtain the wind characteristics, the vibration response characteristics of the stay cable and the deck, the variation of acceleration response RMS vs. wind velocity, the vibration response characteristics comparison between upstream and downstream stay cables, the vibration control efficiency of the dampers on the stay cables, etc. The results can be employed to validate the reliability of current buffeting response calculation techniques, and provide references for wind-resistant design of the super-long-span cable-stayed bridges. Source


Chen Z.,Key Laboratory of Concrete and Prestressed Concrete Structure | Guo T.,Key Laboratory of Concrete and Prestressed Concrete Structure | Yan S.,Jiangsu Province Communications Planning and Design Institute
Shock and Vibration | Year: 2015

Structural health monitoring (SHM) has attracted much attention in recent years, which enables early warnings of structural failure, condition assessments, and rational maintenance/repair strategies. In the context of bridges, many long-span steel bridges in China have been installed with the SHM systems; however, the applications of the SHM in prestressed concrete (PSC) bridges are still rather limited. On the other hand, the PSC box girder bridges are extensively used in highway and railway systems and premature damage of these bridges is often reported, resulting in considerable maintenance and/or replacement costs. First, this paper presents a state-of-art review on the SHM of long-span PSC bridges. Monitoring strategies, methods, and previous applications for these bridges are summarized and discussed. In order to well capture the behavior of the bridge during its whole life and to maximize the use of sensors, a life-cycle monitoring strategy is proposed, in which the sensor layout is determined according to requirements for construction monitoring, completion test, and in-service monitoring. A case study is made on a three-span PSC box girder bridge in China. The system configuration, sensor layout, and data communications, and so forth, are presented. The up-to-date monitored structural responses are analyzed and compared with the design values. © 2015 Zheheng Chen et al. Source


Wang H.,Nanjing Southeast University | Wang H.,Key Laboratory of Concrete and Prestressed Concrete Structure | Li A.Q.,Nanjing Southeast University | Li A.Q.,Key Laboratory of Concrete and Prestressed Concrete Structure | And 4 more authors.
Bridge Maintenance, Safety, Management and Life-Cycle Optimization - Proceedings of the 5th International Conference on Bridge Maintenance, Safety and Management | Year: 2010

The full-scale of bridge buffeting response is essential to the research of bridge wind engineering. Sutong Cable-stayed Bridge (SB) is the longest cable-stayed bridge in the world, and it was attacked by Typhoon Fung-Wong in July 2008. During the typhoon períod, full-scale was conducted to record wind velocities; structural health monitoring system (SHMS) was used to collect the structural vibration responses. In this paper, the measured data are studied using spectral analysis and statistical method. The study includes the analyses of wind characteristics on bridge site and the response characteristics of stay cable and the deck, the relationship of vibrations and wind speed, the comparison of upstream and downstream cable vibrations, the effectiveness of cable dampers and so forth. The results can be employed to validate the current buffeting response calculation method, and provide references for wind-resistant design of the super-long-span cablestayed bridges. © 2010 Taylor & Francis Group, London. Source

Discover hidden collaborations