Lu J.,Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education |
Lu J.,Nanjing Southeast University |
Li N.,Nanjing Forestry University |
Shu G.,Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education |
Shu G.,Nanjing Southeast University
Advanced Steel Construction | Year: 2015
This paper proposed a novel form-finding method for irregular tensegrity structures base on matrix iteration. On the basis of two different forms of structural equilibrium equations, the estimated elemental self-stresses and nodal coordinates were constructed via the singular value decomposition of equilibrium matrix and eigenvalue decomposition of force density matrix, respectively. The configuration of tensegrity that satisfies the specified coordinates was determined through the iterative computation of self-stresses and nodal coordinates, and the constraint condition was introduced in the construction of the estimated nodal coordinates simultaneously. The detailed algorithm procedure was listed and the convergent criterion was also defined. In the end, several illustrated examples were given to prove the validity of the algorithm. Numerical examples and physical models showed that the proposed form-finding method was correct and efficient. The form-finding algorithm could be applied to find tensegrity structures that satisfied the given geometrical forms, and the creation of novel irregular tensegrity, as long as the topological relation and several known coordinate of nodes were given. © 2015 Hong Kong Institute of Steel Construction. All rights reserved.
Ding Y.-L.,Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education |
Wang G.-X.,Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education
Journal of Central South University | Year: 2013
The extreme temperature differences in flat steel box girder of a cable-stayed bridge were studied. Firstly, by using the long-term measurement data collected by the structural health monitoring system installed on the Runyang Cable-stayed Bridge, the daily variations as well as seasonal ones of measured temperature differences in the box girder cross-section area were summarized. The probability distribution models of temperature differences were further established and the extreme temperature differences were estimated with a return period of 100 years. Finally, the temperature difference models in cross-section area were proposed for bridge thermal design. The results show that horizontal temperature differences in top plate and vertical temperature differences between top plate and bottom plate are considerable. All the positive and negative temperature differences can be described by the weighted sum of two Weibull distributions. The maximum positive and negative horizontal temperature differences in top plate are 10.30 C and -13.80 C, respectively. And the maximum positive and negative vertical temperature differences between top plate and bottom plate are 17.30 C and -3.70 C, respectively. For bridge thermal design, there are two vertical temperature difference models between top plate and bottom plate, and six horizontal temperature difference models in top plate. © 2013 Central South University Press and Springer-Verlag Berlin Heidelberg.
Lu J.-Y.,Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education |
Lu J.-Y.,Nanjing Southeast University |
Yan L.-N.,Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education |
Yan L.-N.,Nanjing Southeast University |
And 4 more authors.
Shock and Vibration | Year: 2015
To determine the force mechanism for the steel plate shear wall with slits, the pushover analysis method was used in this study. An estimated equation for the lateral bearing capacity which considered the effect of edge stiffener was proposed. A simplified elastic-plastic analytical model for the stiffened steel slit wall composed of beam elements was presented, where the effects of edge stiffeners were taken into account. The wall-frame analysis model was established, and the geometric parameters were defined. Pushover analysis of two specimens was carried out, and the analysis was validated by comparing the results from the experiment, the shell element model, and a simplified model. The simplified model provided a good prediction of the lateral stiffness and the strength of the steel slit wall, with less than 10% error compared with the experimental results. The mutual effects of the bearing wall and the frame were also predicted correctly. In the end, the seismic performance evaluation of a steel slit wall-frame structure was presented. The results showed that the steel slit wall could prevent the beams and columns from being damaged by an earthquake and that the steel slit wall was an efficient energy dissipation component. © 2015 Jin-yu Lu et al.