A vertical ship lift under earthquake excitation may suffer from a whipping effect due to the sudden change of building lateral stiffness at the top of the ship lift towers.This paper proposes a roof magnetorheologica...A vertical ship lift under earthquake excitation may suffer from a whipping effect due to the sudden change of building lateral stiffness at the top of the ship lift towers.This paper proposes a roof magnetorheological(MR)intelligent isolation system to prevent the seismic whipping effect on machinery structures.Theoretically,the dynamic models of MR damper and the mechanical model of ship lift was established,the inverse neural network controlling algorithm was proposed and the fundamental semi-active control equation for the Three-Gorges ship lift where the MR intelligent isolation system was installed was deduced.Experimentally,the experimental model of the ship lift was given,the vibrating table experiment of the MR intelligent isolation system controlling the whipping effect was carried out and the results of the inverse neural network control strategy and passive isolation strategy were compared.In practical aspect,the large-scale MR damper(500 kN)and a sliding support with limited stiffness were designed and fabricated.It was proven that the MR intelligent isolation system with proper control strategy can greatly reduce the seismic whipping effect on the top workshop of the ship lift and be simple and effective enough to be applied to real engineering structures.展开更多
Large steel space structures,when exposed to a harsh corrosive environment,are inevitably subjected to atmospheric corrosion and stress corrosion cracking.This paper proposes a framework for assessing the corrosion da...Large steel space structures,when exposed to a harsh corrosive environment,are inevitably subjected to atmospheric corrosion and stress corrosion cracking.This paper proposes a framework for assessing the corrosion damage of large steel space structures subjected to both stress corrosion cracking and atmospheric corrosion.The empirical model for estimating atmospheric corrosion based on measured information is briefly introduced.The proposed framework is applied to a real large steel space structure built in the southern coastal area in China to assess its corrosion damage and investigate the effects of atmospheric corrosion on stress corrosion cracking.Based on the results,the conceptual design of the corrosion monitoring system of large steel space structures is finally conducted as the first step for a real corrosion monitoring system.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.50708086).
文摘A vertical ship lift under earthquake excitation may suffer from a whipping effect due to the sudden change of building lateral stiffness at the top of the ship lift towers.This paper proposes a roof magnetorheological(MR)intelligent isolation system to prevent the seismic whipping effect on machinery structures.Theoretically,the dynamic models of MR damper and the mechanical model of ship lift was established,the inverse neural network controlling algorithm was proposed and the fundamental semi-active control equation for the Three-Gorges ship lift where the MR intelligent isolation system was installed was deduced.Experimentally,the experimental model of the ship lift was given,the vibrating table experiment of the MR intelligent isolation system controlling the whipping effect was carried out and the results of the inverse neural network control strategy and passive isolation strategy were compared.In practical aspect,the large-scale MR damper(500 kN)and a sliding support with limited stiffness were designed and fabricated.It was proven that the MR intelligent isolation system with proper control strategy can greatly reduce the seismic whipping effect on the top workshop of the ship lift and be simple and effective enough to be applied to real engineering structures.
基金support from the Hong Kong Polytechnic University through its Niche Area Project in Performance-Based Structural Health Monitoring and the Fundamental Research Funds for the Central University of China(2010-II-019).
文摘Large steel space structures,when exposed to a harsh corrosive environment,are inevitably subjected to atmospheric corrosion and stress corrosion cracking.This paper proposes a framework for assessing the corrosion damage of large steel space structures subjected to both stress corrosion cracking and atmospheric corrosion.The empirical model for estimating atmospheric corrosion based on measured information is briefly introduced.The proposed framework is applied to a real large steel space structure built in the southern coastal area in China to assess its corrosion damage and investigate the effects of atmospheric corrosion on stress corrosion cracking.Based on the results,the conceptual design of the corrosion monitoring system of large steel space structures is finally conducted as the first step for a real corrosion monitoring system.
