Advanced Materials Research Vols. 1065-1069

Abstract: A new type of concrete-filled square steel tubular column to steel-encased concrete composite beam joint is proposed. In order to study the influences of parameters on bearing capacity for the joint formed plastic hinge in the beam end, nonlinear finite element analysis under monotonic loading is conducted by software ANSYS. The results show that axial compression ratio has little influence on joint bearing capacity, and with the increasing of it, the bearing capacity is enhanced slightly. The height of U-shape steel has a significant impact on joint bearing capacity, and with the rise of it, the bearing capacity is enhanced obviously. The thickness of U-shape steel has a comparatively obvious effect on joint bearing capacity with certain limits, and with the growth of it, the bearing capacity of the joint is also grown observably. The diameter of longitudinal reinforcement in the flange slab of beam has some effects on joint bearing capacity, and with the improvement of diameter, the bearing capacity is achieved.

Abstract: Based on equilibrium equation of beam, the displacement interpolating functions with shear effect of spatial beam elements which are used to simulate the structure members of latticed shells are deduced. The different displacement interpolating functions in compression and tension spatial beam-column elements are unified by the method of Maclaurin series expansion, and the unified expressions which are used to simulate structure members are equivalent to those expressed by stability functions. Numerical analyses results indicate that the second-order elastic analysis method for beam structures proposed in this paper, which can perfectly incarnate the second-order effects and the geometrical nonlinearity of the single-layer cylindrical reticulated shell, is of better accurateness and higher effectiveness.

Abstract: Steel silos are commonly constructed by welding together a large number of curved steel panels with lap joints.Where the lap runs horizontally around the silo circumference, the lap connection causes a local eccentricity in the line of vertical thrust in the shell wall. This eccentricity induces high local bending stresses, which are detrimental to the stability of the structure. This paper chooses a flat-bottom squat steel silo as the research object to analyze the stability of lap-jointed steel silo by comparing with a butt-jointed steel silo. By stressing loads calculated according to Chinese code for design of grain steel silos, considering two load cases including axial compression only and combined axial compression and internal pressure, this paper performs numerical analysises including linear buckling analysis, geometric nonlinear elastic analysis and geometrically and materially nonlinear analysis to study the effects of material nonlinearity and lap joint on stability.

Abstract: The safety of reinforced concrete structures will be impacted by the explosions. Using the calculations result of finite element analysis software, combining with database technology, a security level evaluation platform of blasting damage in reinforced concrete structures is established. The platform assesses the safety of damaged structure from the remaining bearing capacity, maximum crack width and maximum deflection, etc. It gives the security level from different aspects of the structure and the integrated security level, and repair advice.

Abstract: This paper reviews the research on the deflection of the orthotropic flat membrane and saddle membrane under the external snow load. First the authors analyze the characteristics of snow load and obtain the standard snow load. Second we build the models of the orthotropic flat membrane and saddle membrane under the snow load. Then we deduce and solve the equations set of the two membranes under the effect of the pretension with the perturbation method. So we obtain the relational expression between the maximum deflection of the membrane’s centre point and the external load. At last, suppose that the load was determinate, the authors analyze the change of the deflection of the centre point of the membrane with different pretensions, side lengths and other parameters.

Abstract: Basing on the finite element analysis software, the emergence of crack under the effect of gradual changed temperature load and the change of stress which are in the condition of super reinforced concrete frame structure are analyzed from the linear and nonlinear numeral simulation. The simulation shows that the structure component under the normal condition is cracked and turn into the nonlinear condition and the steel bars still works under the elastic stage. Meanwhile the actual stage which is reflected by the elastic-plastic analysis of the internal force and deformation is compared by the results which are obtained by the actual project observed results and the calculation of the simplified model. So the distribution of the stress which is caused by the structure temperature reduction is greatly evaluated by the usage of the cracking model which is nonlinear finite element and also plays an important role in the engineering project and practice.

Abstract: Most of the existing building floor roof of brick structure is precast floor slab structures, which structural integrity is not good. In the earthquake, the floor is easy to fall off from the wall, causing casualties and economic losses. Vertical bearing capacity of precast floor slab are usually able to meet the requirements. In most cases the floors have been fall off from the wall before the floors were damaged, Stability of the outer plane of the floor itself to be adequate.By analyzing the patterns and characteristics of precast floor slabs crack under seismic force often appear, this paper presents that the prefabricated floor flat overall reinforcement scheme, which the application of steel band with end portion of the floor a holistic reinforcement,and finite element software ABAQUS be counted cases,the integrity of the reinforced floor to achieve significant improvement, and maximum allowable displacement can be controlled within a limited value.

Abstract: The artificial neural networks (BP-ANN) established by the back-propagation algorithm and early stopping technique. By inputting the properties of geometries and material, BP-ANN model can predict the ultimate shear strength of reinforced concrete frame column. The BP-ANN model based on feed-forward neural network is built, trained and tested using the available test data of 82 RC frame column collected from the technical literature. And the test results are compared and analyzed with predictions based on the current the code of China and ACI code. It shows that the reinforced concrete frame column shear strengths obtained by the simplified model based on BP-ANN are in good agreement with test results, and they are closer to the experimental values than the results designed by models in codes. The BP-ANN model can be used in the shear strength prediction and design for reinforced concrete frame column.

Abstract: Radiant cable suspendome based on single-layer lattice shell is proposed in this paper whose cable-strut system is like that of Radiant Beam String Structure, the purpose of this paper is to do stability analysis of the structure.The linear buckling analysis of the hybrid structure and the single-layer lattice shell who has the same geometry parameters is carried out, we can preliminarily understand the stability of the hybrid structure. At the same time, nonlinear buckling analysis is carried out to study the stability of the hybrid structure under different rise-span ratios, different prestress level and half-span load. The results show that the introduction of prestressed cables greatly improve the structure's stability and reduce the structure sensitivity to original geometrical imperfection.

Abstract: This article analysis stairs effect on steel frame structure under seismic loading by using the finite element software MIDAS Gen. Detailed analyzing impact of stairs on the self-vibration period, period ratio, the story drift and other design indexes in designing of the impact under seismic loading. Analysis shows that stairs have great effects on the design index of steel frame structure. Therefore the stair effect must be considered in analysis of structure design and modeling.