Abstract: Tests on two simple supported steel bar truss and concrete superimposed floor slabs have been carried out to study their mechanic behavior and bearing capacities. The one is prefabricated steel truss concrete slab without temporary support in the mid-span to simulate its mechanic status in construction stage, the other is superimposed board (prefabricated + post-cast layer) in use phase. Test results show that the deformation of the prefabricated steel truss concrete slab in construction stage meets the requirement of the Code, and the slab is mainly controlled by deflection instead of cracks; Performance of superimposed board is excellent in use stage; and the steel bar is elastic in both stages during the tests.
Abstract: Based on the coupled precise time integration method and basic assumptions of constant average acceleration method in Newmark family, implicit series solution of structural dynamic equation is put forward by introducing the Taylor series expansion. Relevant time step integration formulas were designed. Stability and accuracy of the method were analyzed. Stability analyses show that the coupling implicit method is stable when damping ratio is equal to 0, and is conditionally stable when damping ratio are other values. The results show that the accuracy of the algorithm can be controlled by choosing the number of truncation order of Taylor series expansion and is better than that of traditional scheme with the increase of time step. Number examples are given to demonstrate the validity of the proposed method.
Abstract: Considering core thickness is important issue to performance of exterior frame and core hybrid structure in high-rise buildings, seismic response analysis is conducted by response spectrum method for finite element models with different core thickness. The optimization design of core thickness of hybrid Structures on the basis of the seismic response is studied, the core thicknesses are chosen as design variables, the objective function about core volume is adopted, some specification requirements such as deformation, the ratio of lateral stiffness to gravity, storey shear to gravity, storey shear of exterior frame, axial compression ratio of column and wall limb, bearing capacity of structural member and core construction are regarded as restricting conditions, the optimal mathematical model is established for reflecting integrity dynamic properties of hybrid structure. The ANSYS software is used for optimizing tool, the hybrid structures optimization design are made through different initial values for verifying convergence of optimization method, the optimal result show that the performances of hybrid structure are improved, the internal forces are reduced and the ratios of inner force born by exterior frames are increased in the optimal scheme.
Abstract: The wind tunnel tests of some typical large roofs, including a saddle roof, pitched roof and domes, are carried out with various terrains which cover suburban and urban exposures. The wind pressure data of roofs are obtained by using the synchronous multi-pressure scanning technique. The wind pressure coefficient and local shape factors of the wind load was investigated. The effects of various terrains on wind pressures of roofs are discussed. From the results, we can see mean pressures of these roofs exposed to the mean pressures exposed to the suburban terrain are 2 or 3 times those exposed to the urban terrain. And the terrains are no directly influence to the wind pressure shape factors.
Abstract: Abstract. In order to avoid the damage of precision guided weapons on target, a steel fiber reinforced concrete sandwich structure with different types of support was proposed. The failure characteristics of penetration plate, steel fiber reinforced concrete plate and support beam were studied by contact explosion test. The results showed that the using of steel fiber sheet sandwich structure could increase a resistance level for the project with the same thickness of the protective layer. The failure mode of steel fiber reinforced concrete sandwich structure under partial blast loading was still the local damage mode, the strength and thickness of steel fiber laminate material, height and spacing of support beam were the main factors to control the effect of wave attenuation in steel fiber reinforced concrete sandwich structure, if some measures to prevent vibration on steel fiber sheet or under-surface of vault would enhance the resistance of structure.
Abstract: Failure-mode based optimization is very effective at improving the performance of structure, therefore, a new optimal approach based on failure mode with the ability to limit the cost is proposed. Three different failure modes of the coupled wall are discussed, and then the objective function is setted up according to the expected failure mode and minimum cost. Finally, an example is cited to verify the method. It is concluded that the method can supply an effective way to reduce the cost of coupled shear wall, and the expected failure mode can be obtained.
Abstract: This paper presents the structural behaviour of composite beams with various floor systems tested in full-scale arrangement. Six full-scale specimens with staggered and non-staggered arrangement of studs on the composite beams were tested until failure. The moment capacities obtained from the experiment are compared with the theoretical values established from BS 5950 and Eurocode 4. The experimental results showed good agreement with theoretical predictions while no significant influences were found between staggered and non-staggered arrangement of studs.
Abstract: To investigate the spatial performance of concrete filled steel tubular arch with corrugated steel webs, a static loading test has been conducted on an arch with a clear span of 6m subjected to in-plane and out-of-plane loading simultaneously. The structural behaviors such as load-displacement relation, ductility, distribution of strains in tubes and corrugated webs, were explored. Based on the results, it is demonstrated that the lateral deformation is the critical factor for the ultimate load-carrying capacity of the arch. In the whole process of test for the tubular arch, material non-linearity is dominant and geometrical non-linearity is subordinate. It could be concluded that the CFST-CSW arch shows good structural behavior and may be applicable in practice.
Abstract: With the increasingly sophisticated theory of concrete filled steel tube (CFST) and its’ wide application, how to make the CFST steel beam-column joints (SBCJS) becomes one of the key problems in research. According to the relevant references in and abroad, types and research done on CFST SBCJ are introduced, including outer annular-stiffener type, Inner stiffening ring type connection with anchorages type, beam integral breakthrough type etc. Finally the key problems need to be further studied are promoted.