The Experts below are selected from a list of 4461 Experts worldwide ranked by ideXlab platform
Dongdong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Torsional behavior of a hybrid FRP-aluminum Space Truss bridge: Experimental and numerical study
Engineering Structures, 2018Co-Authors: Dongdong Zhang, Qilin Zhao, Jie Tao, Yifeng GaoAbstract:Abstract A novel lightweight hybrid fiber-reinforced polymer (FRP) – aluminum Space Truss structure that consists of two triangular deck-Truss beams has been designed for rapid emergency bridging system. This paper reports a large-scale pure torsion test on a cantilever full-scale specimen to evaluate the detailed linear-elastic torsional behavior and the load-carrying mechanism of the hybrid twin-trackway spatial structure. Additionally, a structural computational finite element model (FEM) was constructed and validated against the experiments. To fully understand the load-carrying mechanism obtained from the experiments, numerical analyses were performed by equivalently converting the torsion reaction of the hybrid twin-trackway structure to the bending and torsion of its twin triangular deck-Truss beams. The results indicate that the experimental structure exhibits a good and specific torsional response, which can be well described by FEM. The unidirectional pultruded FRP profiles are mainly subjected to axial forces and are thus appropriate for application to this unique twin-trackway Space Truss, unlike in the case of the alone single-trackway triangular beam under torsion. The vertical bending of the twin triangular deck-Truss beams play a key role in the behavior of load-carrying of the entire bridge, unlike in the case of the conventional torsional calculation method for the separated box beam. In the initial design, the torsional calculation of such a novel bridge can be carried out using the flexural analytical and numerical models of the triangular deck-Truss beam.
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experimental and numerical study of the torsional response of a modular hybrid frp aluminum triangular deck Truss beam
Engineering Structures, 2017Co-Authors: Dongdong Zhang, Qilin Zhao, Yaxin HuangAbstract:Abstract A hybrid fiber-reinforced polymer (FRP) – aluminum modular Space Truss emergency bridge has been designed that consists of two triangular deck-Truss beams incorporating a new structural form and advanced pultruded FRP profiles. As a fundamental investigation, this paper explores the detailed torsional behaviors of the new triangular deck-Truss beam. A full-scale specimen was prepared and tested under pure torsion to evaluate the representative structural performances. A three-dimensional finite element model (FEM) was constructed and validated with experimental results showing good comparisons. Furthermore, the torsional behavior of the triangular deck-Truss beam was numerically investigated by removing individual primary Truss members to clearly understand the load transfer mechanism. It was found that the beam exhibited a specific and unfavorable mechanical behavior prohibiting full utilization of the FRP material' potential. The external torsional moment is confirmed to be primarily resisted by the torsion of the longitudinal profiles and the in-plane bending of the bilateral Vierendeel Trusses rather than the out-of-plane bending of the web diagonals. Possible improvement and optimization procedures are further suggested for this beam when solely used as a structure subjected to off-axis load or pure torsion.
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analytical solutions of the torsional mechanism for a new hybrid fiber reinforced polymer aluminum twin trackway Space Truss bridge
Advances in Structural Engineering, 2016Co-Authors: Dongdong Zhang, Qilin Zhao, Yingchang DuanAbstract:For emergency purposes, a lightweight Space Truss bridge was designed. The bridge is composed of twin triangular deck-Truss beams incorporating new structural forms and advanced fiber-reinforced po...
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flexural properties of a lightweight hybrid frp aluminum modular Space Truss bridge system
Composite Structures, 2014Co-Authors: Dongdong Zhang, Qilin Zhao, Yaxin Huang, Haosen Chen, Dasheng MiaoAbstract:Abstract A hybrid FRP-aluminum Space Truss structure system was designed as a modular emergency bridge with a span of 12 m. The bridge has a light weight of only approximately 1.2 tons and contains 8 structural units, which are composed of an aluminum bridge deck supported by FRP Trussed members and connected by male jugs and female jaws based on the pre-tightened teeth connection (PTTC) technique. In the paper, the conceptual design of the bridge, assembly of structural units and bridge erection are described in detail. To understand the actual flexural behavior of the bridge, 4 prototype structural units were fabricated and mounted as a single-span simply supported structure and subjected to the four-point bending loading test. Structural computational models, including two FE models and a simplified analytical planar model, were constructed and validated by the experimental results. The results indicated that (1) the specimen displayed linear behavior under the ultimate-limit-state loading level, and both the strength and stiffness satisfied the design requirements; (2) the bridge deck exhibited an unexpected complex strain distribution, which is different from that of the analogous structure; and (3) the “beam-grillage” FE model and simplified analytical planar model provided effective calculation methods for the proposed bridge.
D Tran - One of the best experts on this subject based on the ideXlab platform.
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damage location vector a non destructive structural damage detection technique
Computers & Structures, 2005Co-Authors: D Huynh, J He, D TranAbstract:This paper presents a method for structural damage detection using frequency response functions (FRF) obtained from non-destructive vibration tests. It investigates the case of early structural damage in which there is no appreciable change in mass and damping. The resulting change in structural stiffness matrix is reflected in changes of FRF data which can be exemplified by the evaluation of damage location vector (DLV). This evaluation requires the dynamic stiffness matrix of the undamaged (virgin) structure and the change in frequency response functions of the currently damaged structure. In this paper the former is obtained from a finite element model of the virgin structure and the latter are obtained from the finite element modelling (FEM) and from impact hammer test. The method is applied to a Space Truss structure and a plate structure. Effects of noise, both numerically simulated and measured are also investigated. Preliminary results show that this method of Damage Location Vector can overcome the problems of coordinate incompatibility and noise and deliver encouraging results on damage detection.
Dasheng Miao - One of the best experts on this subject based on the ideXlab platform.
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flexural properties of a lightweight hybrid frp aluminum modular Space Truss bridge system
Composite Structures, 2014Co-Authors: Dongdong Zhang, Qilin Zhao, Yaxin Huang, Haosen Chen, Dasheng MiaoAbstract:Abstract A hybrid FRP-aluminum Space Truss structure system was designed as a modular emergency bridge with a span of 12 m. The bridge has a light weight of only approximately 1.2 tons and contains 8 structural units, which are composed of an aluminum bridge deck supported by FRP Trussed members and connected by male jugs and female jaws based on the pre-tightened teeth connection (PTTC) technique. In the paper, the conceptual design of the bridge, assembly of structural units and bridge erection are described in detail. To understand the actual flexural behavior of the bridge, 4 prototype structural units were fabricated and mounted as a single-span simply supported structure and subjected to the four-point bending loading test. Structural computational models, including two FE models and a simplified analytical planar model, were constructed and validated by the experimental results. The results indicated that (1) the specimen displayed linear behavior under the ultimate-limit-state loading level, and both the strength and stiffness satisfied the design requirements; (2) the bridge deck exhibited an unexpected complex strain distribution, which is different from that of the analogous structure; and (3) the “beam-grillage” FE model and simplified analytical planar model provided effective calculation methods for the proposed bridge.
Leandro Jose Rocha Da Costa - One of the best experts on this subject based on the ideXlab platform.
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discussion discussion on the logarithmic strain measure applied to the nonlinear positional formulation for Space Truss analysis finite element in analysis and design 45 2009 632 639 and nonlinear positional formulation for Space Truss analysis finite element in analysis and design 42 2006 1079 1086
Finite Elements in Analysis and Design, 2012Co-Authors: Marcelo Greco, Leandro Jose Rocha Da CostaAbstract:This discussion presents the application of the classical strain measures, and their energy conjugated stress pairs, to obtain a consistent geometrically nonlinear formulation based on the Finite Elements Method (FEM), particularly applied to the numerical analysis of Space Trusses. The development is performed using a numerical formulation based on a kinematical description that takes as reference only the global coordinates of the finite elements. This numerical approach is interesting because it is not necessary to use local systems of reference in the finite elements to describe the kinematics of the problem. The invariance on the formulation for the different strain measures is proved here.
Qilin Zhao - One of the best experts on this subject based on the ideXlab platform.
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Torsional behavior of a hybrid FRP-aluminum Space Truss bridge: Experimental and numerical study
Engineering Structures, 2018Co-Authors: Dongdong Zhang, Qilin Zhao, Jie Tao, Yifeng GaoAbstract:Abstract A novel lightweight hybrid fiber-reinforced polymer (FRP) – aluminum Space Truss structure that consists of two triangular deck-Truss beams has been designed for rapid emergency bridging system. This paper reports a large-scale pure torsion test on a cantilever full-scale specimen to evaluate the detailed linear-elastic torsional behavior and the load-carrying mechanism of the hybrid twin-trackway spatial structure. Additionally, a structural computational finite element model (FEM) was constructed and validated against the experiments. To fully understand the load-carrying mechanism obtained from the experiments, numerical analyses were performed by equivalently converting the torsion reaction of the hybrid twin-trackway structure to the bending and torsion of its twin triangular deck-Truss beams. The results indicate that the experimental structure exhibits a good and specific torsional response, which can be well described by FEM. The unidirectional pultruded FRP profiles are mainly subjected to axial forces and are thus appropriate for application to this unique twin-trackway Space Truss, unlike in the case of the alone single-trackway triangular beam under torsion. The vertical bending of the twin triangular deck-Truss beams play a key role in the behavior of load-carrying of the entire bridge, unlike in the case of the conventional torsional calculation method for the separated box beam. In the initial design, the torsional calculation of such a novel bridge can be carried out using the flexural analytical and numerical models of the triangular deck-Truss beam.
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experimental and numerical study of the torsional response of a modular hybrid frp aluminum triangular deck Truss beam
Engineering Structures, 2017Co-Authors: Dongdong Zhang, Qilin Zhao, Yaxin HuangAbstract:Abstract A hybrid fiber-reinforced polymer (FRP) – aluminum modular Space Truss emergency bridge has been designed that consists of two triangular deck-Truss beams incorporating a new structural form and advanced pultruded FRP profiles. As a fundamental investigation, this paper explores the detailed torsional behaviors of the new triangular deck-Truss beam. A full-scale specimen was prepared and tested under pure torsion to evaluate the representative structural performances. A three-dimensional finite element model (FEM) was constructed and validated with experimental results showing good comparisons. Furthermore, the torsional behavior of the triangular deck-Truss beam was numerically investigated by removing individual primary Truss members to clearly understand the load transfer mechanism. It was found that the beam exhibited a specific and unfavorable mechanical behavior prohibiting full utilization of the FRP material' potential. The external torsional moment is confirmed to be primarily resisted by the torsion of the longitudinal profiles and the in-plane bending of the bilateral Vierendeel Trusses rather than the out-of-plane bending of the web diagonals. Possible improvement and optimization procedures are further suggested for this beam when solely used as a structure subjected to off-axis load or pure torsion.
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analytical solutions of the torsional mechanism for a new hybrid fiber reinforced polymer aluminum twin trackway Space Truss bridge
Advances in Structural Engineering, 2016Co-Authors: Dongdong Zhang, Qilin Zhao, Yingchang DuanAbstract:For emergency purposes, a lightweight Space Truss bridge was designed. The bridge is composed of twin triangular deck-Truss beams incorporating new structural forms and advanced fiber-reinforced po...
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flexural properties of a lightweight hybrid frp aluminum modular Space Truss bridge system
Composite Structures, 2014Co-Authors: Dongdong Zhang, Qilin Zhao, Yaxin Huang, Haosen Chen, Dasheng MiaoAbstract:Abstract A hybrid FRP-aluminum Space Truss structure system was designed as a modular emergency bridge with a span of 12 m. The bridge has a light weight of only approximately 1.2 tons and contains 8 structural units, which are composed of an aluminum bridge deck supported by FRP Trussed members and connected by male jugs and female jaws based on the pre-tightened teeth connection (PTTC) technique. In the paper, the conceptual design of the bridge, assembly of structural units and bridge erection are described in detail. To understand the actual flexural behavior of the bridge, 4 prototype structural units were fabricated and mounted as a single-span simply supported structure and subjected to the four-point bending loading test. Structural computational models, including two FE models and a simplified analytical planar model, were constructed and validated by the experimental results. The results indicated that (1) the specimen displayed linear behavior under the ultimate-limit-state loading level, and both the strength and stiffness satisfied the design requirements; (2) the bridge deck exhibited an unexpected complex strain distribution, which is different from that of the analogous structure; and (3) the “beam-grillage” FE model and simplified analytical planar model provided effective calculation methods for the proposed bridge.