Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander ...Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander with four-legged truss structure is proposed. In the premise of ensuring that the main and assistant structures of landing legs are not changed, six possible lander body structures of the new lander are put forward. Taking the section size of each component of lander as design variables, and taking the total mass of the structure as the objective function, the six structures are analyzed by using the software Altair. OptiStruct and the results show that the mass of the basic structure is the lightest, and it is selected as the final design scheme of lander due to its simple structure and convenient manufacture. The optimization on the selected lander structure is conducted, and the detailed results are presented.展开更多
The Philippine Arena Project is a large domed roof structure. The arena volume is significant, with 227 m x 179 m ellipse shaped space standing, which is the largest non-column arena in the world. Reinforced concrete ...The Philippine Arena Project is a large domed roof structure. The arena volume is significant, with 227 m x 179 m ellipse shaped space standing, which is the largest non-column arena in the world. Reinforced concrete is used for the bowl structure and main seismic resisting system is considered as dual system. For the structure above Level 04, steel rakers and columns are applied. To identify seismic resisting performance of steel structure, push over analysis had been carried out. Pre-cast concrete plank is planned for arena seating to meet constructing ability. The roof structure is grid type space frame. Tension trusses are located under the space frame for overall stability of roof structure. Wind tunnel test had been conducted to evaluate accurate wind pressure for both structure and cladding design. LRB （lead rubber bearing） is located under the roof structure to reduce seismic force delivered from sub-structure.展开更多
In the centre of the famous Chinese painting, Qingrning Shanghe Tu, an arch-shaped timber bridge, Hongqiao, stands like a rainbow over the river Bianhe. Unfortunately, Hongqiao was damaged during floods from the Yello...In the centre of the famous Chinese painting, Qingrning Shanghe Tu, an arch-shaped timber bridge, Hongqiao, stands like a rainbow over the river Bianhe. Unfortunately, Hongqiao was damaged during floods from the Yellow River, and we can only see her beautiful form in Qingming Shanghe Tu. While, the geometrical dimensions, structural principle, as well as the construction methods of the bridge are still an interesting mystery. In the present paper, the author uncovers the structural principle and the geometric dimensions of the bridge as well as its history background. Furthermore, the author introduces two new structural systems, Lap-Beam and 1.5-Layer space frame, which are inspired by the structural principle of the Hongqiao.展开更多
This paper presents an effective approach for updating finite element dynamic model from incomplete modal data identified from ambient vibration measurements.The proposed method is based on the relationship between th...This paper presents an effective approach for updating finite element dynamic model from incomplete modal data identified from ambient vibration measurements.The proposed method is based on the relationship between the perturbation of structural parameters such as stiffness and mass changes and the modal data measurements of the tested structure such as measured mode shape readings.Structural updating parameters including both stiffness and mass parameters are employed to represent the differences in structural parameters between the finite element model and the associated tested structure.These updating parameters are then evaluated by an iterative solution procedure,giving optimised solutions in the least squares sense without requiring an optimisation technique.In order to reduce the influence of modal measurement uncertainty,the truncated singular value decomposition regularization method incorporating the quasi-optimality criterion is employed to produce reliable solutions for the structural updating parameters.Finally,the numerical investigations of a space frame structure and the practical applications to the Canton Tower benchmark problem demonstrate that the proposed method can correctly update the given finite element model using the incomplete modal data identified from the recorded ambient vibration measurements.展开更多
基金Sponsored by the Project on Absorption of Intellects by Institutions of Higher Education for Academic Disciplinary Innovations(Grant No. B07018)
文摘Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander with four-legged truss structure is proposed. In the premise of ensuring that the main and assistant structures of landing legs are not changed, six possible lander body structures of the new lander are put forward. Taking the section size of each component of lander as design variables, and taking the total mass of the structure as the objective function, the six structures are analyzed by using the software Altair. OptiStruct and the results show that the mass of the basic structure is the lightest, and it is selected as the final design scheme of lander due to its simple structure and convenient manufacture. The optimization on the selected lander structure is conducted, and the detailed results are presented.
文摘The Philippine Arena Project is a large domed roof structure. The arena volume is significant, with 227 m x 179 m ellipse shaped space standing, which is the largest non-column arena in the world. Reinforced concrete is used for the bowl structure and main seismic resisting system is considered as dual system. For the structure above Level 04, steel rakers and columns are applied. To identify seismic resisting performance of steel structure, push over analysis had been carried out. Pre-cast concrete plank is planned for arena seating to meet constructing ability. The roof structure is grid type space frame. Tension trusses are located under the space frame for overall stability of roof structure. Wind tunnel test had been conducted to evaluate accurate wind pressure for both structure and cladding design. LRB （lead rubber bearing） is located under the roof structure to reduce seismic force delivered from sub-structure.
文摘In the centre of the famous Chinese painting, Qingrning Shanghe Tu, an arch-shaped timber bridge, Hongqiao, stands like a rainbow over the river Bianhe. Unfortunately, Hongqiao was damaged during floods from the Yellow River, and we can only see her beautiful form in Qingming Shanghe Tu. While, the geometrical dimensions, structural principle, as well as the construction methods of the bridge are still an interesting mystery. In the present paper, the author uncovers the structural principle and the geometric dimensions of the bridge as well as its history background. Furthermore, the author introduces two new structural systems, Lap-Beam and 1.5-Layer space frame, which are inspired by the structural principle of the Hongqiao.
文摘This paper presents an effective approach for updating finite element dynamic model from incomplete modal data identified from ambient vibration measurements.The proposed method is based on the relationship between the perturbation of structural parameters such as stiffness and mass changes and the modal data measurements of the tested structure such as measured mode shape readings.Structural updating parameters including both stiffness and mass parameters are employed to represent the differences in structural parameters between the finite element model and the associated tested structure.These updating parameters are then evaluated by an iterative solution procedure,giving optimised solutions in the least squares sense without requiring an optimisation technique.In order to reduce the influence of modal measurement uncertainty,the truncated singular value decomposition regularization method incorporating the quasi-optimality criterion is employed to produce reliable solutions for the structural updating parameters.Finally,the numerical investigations of a space frame structure and the practical applications to the Canton Tower benchmark problem demonstrate that the proposed method can correctly update the given finite element model using the incomplete modal data identified from the recorded ambient vibration measurements.
