This paper presents a structural vulnerability analysis method based on the theory of plastic limit analysis.By applying the mechanism generation method,the ultimate loading factor and the corresponding failure mode o...This paper presents a structural vulnerability analysis method based on the theory of plastic limit analysis.By applying the mechanism generation method,the ultimate loading factor and the corresponding failure mode of a structural system can be obtained.The ultimate loading factor was then used to measure the performance of a structural system.The variation of this factor to different damage scenarios due to vehicle collision was investigated.To illustrate the proposed method,two cases study on statically determinate and statically indeterminate truss bridge were performed.The results of the case study showed that the susceptibility of structure performance to local damage scenarios not only depends on the location but also the severity of the damage scenarios.Based on this analysis,structural capacity can be evaluated and structural management and maintenance strategy can be made more efficiently.展开更多
Tower cranes are commonly used facilities for the construction of high-rise structures.To ensure their workability,it is very important to analyze their response and evaluate their condition under extreme conditions.T...Tower cranes are commonly used facilities for the construction of high-rise structures.To ensure their workability,it is very important to analyze their response and evaluate their condition under extreme conditions.This paper proposes a general scheme for safety and serviceability assessment of high-rise tower crane to turbulent winds based on time domain buffeting response analysis.Spatially correlated wind velocity field at the location of the tower crane was first simulated using an algorithm for generating the time domain samples of a stationary,multivariate stochastic process according to some prescribed spectral density matrix.The buffeting forces applied to the structure were computed according to the above-simulated wind velocity fluctuations and the lift,drag,and moment coefficients obtained from a CFD computation.Those spatially correlated loads were then fed into a well calibrated finite element model and the nonlinear time history analysis was conducted to compute structural buffeting response.Compared with structural onsite response measurement,the computed response using the proposed method has good precision.The proposed method is then adopted for analyzing the buffeting response of an in-use tower crane under the design wind speed and the maximum operational wind speed for safety and serviceability assessment.展开更多
基金Sponsored by the Key Program of National Nature Science Foundation of China (Grant No. 50538020)the National High Technology Research and Development Program of China (Grant No. 2006AA11Z109)the Key Research Project of Chinese State Key Laboratory for Disaster Reduction in Civil Engineering (Grand No. SLDRCE08-A-05)
文摘This paper presents a structural vulnerability analysis method based on the theory of plastic limit analysis.By applying the mechanism generation method,the ultimate loading factor and the corresponding failure mode of a structural system can be obtained.The ultimate loading factor was then used to measure the performance of a structural system.The variation of this factor to different damage scenarios due to vehicle collision was investigated.To illustrate the proposed method,two cases study on statically determinate and statically indeterminate truss bridge were performed.The results of the case study showed that the susceptibility of structure performance to local damage scenarios not only depends on the location but also the severity of the damage scenarios.Based on this analysis,structural capacity can be evaluated and structural management and maintenance strategy can be made more efficiently.
基金supported by the National Natural Science Foundation of China(Grant No.50508027)the Key Program of NSFC(Grant No.50538020)the 863 Program of Ministry of Science and Technology of China(No.2006AA11Z109).
文摘Tower cranes are commonly used facilities for the construction of high-rise structures.To ensure their workability,it is very important to analyze their response and evaluate their condition under extreme conditions.This paper proposes a general scheme for safety and serviceability assessment of high-rise tower crane to turbulent winds based on time domain buffeting response analysis.Spatially correlated wind velocity field at the location of the tower crane was first simulated using an algorithm for generating the time domain samples of a stationary,multivariate stochastic process according to some prescribed spectral density matrix.The buffeting forces applied to the structure were computed according to the above-simulated wind velocity fluctuations and the lift,drag,and moment coefficients obtained from a CFD computation.Those spatially correlated loads were then fed into a well calibrated finite element model and the nonlinear time history analysis was conducted to compute structural buffeting response.Compared with structural onsite response measurement,the computed response using the proposed method has good precision.The proposed method is then adopted for analyzing the buffeting response of an in-use tower crane under the design wind speed and the maximum operational wind speed for safety and serviceability assessment.
