Papers by Keyword: Brace

Abstract: Due to mechanical performances of brace and steel plate, mechanical properties of semi-rigid joints and its construction and installation, semi-rigid steel frame-braced steel plate shear wall system is proposed. Nonlinear static analysis with parameters (thickness of plate, type of brace, size of brace and the ratio of span to height) changed of a single-span and single-floor semi-rigid steel frame-braced steel plate shear wall system illustrates that braced steel plate shear walls contributes obviously to bearing capacity and lateral rigidity of semi-rigid steel frame. Also, the finite element analysis (by ANSYS) show that semi-rigid steel frame-braced steel plate shear wall system has excellent ductility.

Abstract: As the development of structural system and material enable to construct many high-rise buildings. However, high rise buildings are vulnerable to the strong wind rather than seismic excitation, because they have relatively long period. Recently, intensity and frequency of extreme wind such as hurricane and typhoon have been increased with the weather change all over the world. Therefore, in this study, 50-story building with three types of braces which are diagonal brace, X-brace, Chevron brace are modelled and compared with non-braced 50-story building by changing wind speed. Finally, all the results from four cases are compared for wind performances. As a result, buildings reinforced with X-brace and Chevron braces have a good performance subjected to the strong wind.

Abstract: A type automobile belt tensioner brace parts need many times of the clamping in the process of machining, which will lead to the low accuracy ,low efficiency and high cost and so on. This paper based on the structural feature of the brace provided a special fixture for the brace and built a Petri nets model to describe the work process in detail by the analysis of the fixture‘s positioning ,the clamping process analysis and the clamping force analysis. Moreover , This fixture can clamp two belt tensioner brace at the same time during completing the three machining surface of workpiece without changing the fixture,which can clamp the workpiece more convenient with higher positioning accurate ,higher machinging accuracy and lower cost. This fixture has passed the practical proof , which provied a reference for designing a fixture to clamp a workpiece with more complex surface .

Abstract: Most of the design programs used in the foundation excavation protection can only simulate and calculate the model of semi-infinite soil. While the limited soil is usually came across during practical engineering, especially in the center of large city. So the results of calculations in these situation can not ensure the security and economy. In this paper, based on a bracing foundation excavation protection project in limited soil, calculate the active soil pressure using MATHCAD, then analyze the bracing reaction force through the equivalent beam method. Finally, comparing the results with the simulation of ABAQUS, the method above could used in the similar situation in the further design of foundation excavation protection.

Abstract: Direct tensile testing machines are the necessary to study tensile property of rocks. However, a traditional testing machine has the weakness of absenting effective subjacent brace. So, the whole tensile experiment can not be done completely. By using elastic brace, the whole tensile experiment really can be finished, then we can get the stress-strain curve. But, the samples are destroyed around incorrect planes. Aiming at the disadvantage of the machines, the author brings forward a new method of improving the direct tensile testing machine by using two magnets as the subjacent brace with magnetic levitation function. In this article, the author analyses the reasons why magnetic levitation can offer support and explains the components of the brace, its installation and principles. At last, the authors analyze the design idea and the technical effect of the brace.

Abstract: The brace at the mid-span of beam of portal frame provides lateral constraint and improves its overall stability. By the nonlinear finite element method, the influences of structural parameters on the required bracing force for the beam bearing ultimate load were investigated when only one brace acting on the upper flange of beam at mid-span. The bracing force is correlated to the failure mode and configuration of beam of portal frame. The failure of beam trends to be controlled by the strength and the required bracing force increases when the stiffness of column increases. The required bracing force corresponding to the beam subjected to the ultimate load increases when the span of beam or the width of beam flange increases. The research work can be used as reference for the brace design for beam of portal frame.

Abstract: Earthquake would cause unacceptable damage in reinforced concrete structures. In this paper, two retrofitting methods based on alternative load path are proposed for the reinforced concrete structure. One method is to add steel braces to the structure, and another one is to add tension cables to the structure. Pushover analyses for all frames are carried out using SAP2000. From the analysis results, steel braces or tension cables delay the formation of the first plastic hinge and failure of columns, and can better improve the seismic performance of reinforced concrete frame. The research results can be utilized for displacement-based seismic design and seismic performance evaluation of RC structures.

Abstract: In order to investigate the seismic performance of zipper frames, three 10-storey structure models, including a zipper frame with tension zipper columns, a zipper frame with weak zipper columns and a chevron braced frame, were designed. Some indexes, including the natural periods, steel consumption and dynamic response under frequent and rare earthquakes, were analyzed and compared. The results show that, the dynamic responses of the three structures are similar to each other and all of them can meet the requirement of no-damage under frequent earthquakes and no-collapse under rare earthquakes provided by the GB50011 code, but the steel consumption for the zipper frames is less than that of the chevron braced frames, indicating the comprehensive seismic performance of the zipper frame is better than the chevron braced frame. However, it is also found that the design method of the zipper columns is conservative and a more reasonable design method of the zipper columns is needed to be provided.

Abstract: Occurrence of frequency of earthquakes around the world has been increased including Sendai earthquake in Japan and magnitude of earthquake has also increased. Recently, many tall buildings using local seismic codes can be exposed to the risk of an earthquake and wind. Also, some buildings, which was planned to be built, were foundered as a result of lack of finance. Therefore, for tall buildings, structural safety such as earthquake and wind resistant performance, and financing issue are very important to progress the huge project. So we need to find another optimum alternative other than damping devices and base isolation system. In this study, four types of test specimens are used, which are fifty-story base tall building, tall building that was reinforced with diagonal brace, x-brace, and Chevron brace. And all of these cases, are subjected to the seismic load and wind load, finally analyzed and compared for seismic and wind performances.

Abstract: A hysteretic model of conventional steel braces consisting of 18 parameters is proposed. This model is able to simulate the hysteretic behavior of conventional steel braces accurately. The collapse-prevention strengthening effect with steel braces for a typical reinforced concrete (RC) frame that was close to the epicenter and collapsed during the Great Wenchuan Earthquake is discussed via push-over analysis and collapse fragility analysis based on incremental dynamic analysis. The result could be referred to for the seismic collapse prevention design of RC frames.