Applied Mechanics and Materials Vols. 351-352

Abstract: To induce the ductile behavior of ultra high performance concrete beams, the experiments to find out the best composition of volume fraction of steel fiber and ratio of reinforcement bar were carried out. 15 UHPC beams which have various combinations of volume fraction of steel fiber and ratio of reinforcement bar. The reinforcement bars was consist of 2×1, 3×3, 4×4, 5×4. The volume fractions of steel fibers were 0%, 0.7%, 1%, 1.5%, 2%. The beam which has 0% volume fraction with the close placement reinforcement bar has little effect on ductile behavior. At least 0.7% volume fraction with the close placement reinforcement bar guarantees the ductile behavior of UHPC beam.

Abstract: Pushover method is mainly used to find the weak part of the structure and possible failure modes. This paper presents a pushover analysis. Taking a transmission tower as an example, calculations are carried out by SAP2000 Program with assumption of rational criterion. Seismic loads of frequently met and rarely met seismic concentration degrees are considered. By comparing the structural target seismic performance and the sequence of plastic hinges induced, seismic performances of the transmission tower are estimated.

Abstract: Glass as a building material is quite used nowadays. In the Czech Republic, the glass is still considered only as a filler material; therefore assessment of them in terms of statics is difficult. This paper deals with the issue of designing of sheet of glass of railing in the Czech Republic. This article describes the process of bending tests of multilayer glass of comparable thicknesses and analyzes its behavior in terms of safety and maximum load.

Abstract: By testing the seismic performance of the beams and columns of three SRHC with different axial compression ratios, the paper reveals the influence pattern of the nodes’ stress transfer and distribution, cracks’ appearance and development, member deformation, destruction pattern and mechanism, energy dissipation capacity etc., in SRHC with different axial compression ratios. The test shows that the increase of axial compression ratio postpones the appearance of the diagonal cracks in the nodes area, and slows down moderately the speed of development of the diagonal cracks, and improves the nodes’ energy dissipation capacity and ductility etc. this article studies its crack resistance and bearing capacity only. The purpose of this test is, through the low cyclic loading test of the nodes in the beams and columns of three SRHC with different axial compression ratios, to investigate the axial compression ratio’ influence on the cracks’ appearance, development, destruction pattern and deformation characteristics in the nodes; to analyze of the factors influencing the load-carrying capability; to validate the calculation methods proposed by related studies, which is little studied by foreign countries. This paper, based on the analysis of axial compression ratio test, further validates and improves the theory and methods proposed in the literature.

Abstract: The semi-rigid steel frame-composite steel plate shear wall structure (SCSW) effectively improves the lateral stiffness of shear wall, making it possible to use the semi-rigid joint. In order to study the plastic failure mechanism of SCSW, a plastic model is established, in which the effects of the rotations of semi-rigid joints and yield deformations of infill steel walls on the energy consumption are considered. Based on that, a design method for the lateral ultimate strength is put forward and a nonlinear FEM model is setup using ANSYS. Through the comparison between plastic analysis results with the finite element results, it is shown that the plastic analysis method is feasible and has a safe redundancy.

Abstract: Steel concentrically-braced frames (CBFs) as a lateral force resisting system are widely used in moderate seismic regions. The collapse capacity of CBF is uncertain in prior study so that an appropriate analysis method is hard to hunt. Incremental Dynamic Analysis (IDA) is an efficient method to evaluate the dynamic instability of structure. The IDA is incorporated in evaluation of collapse capacity of CBFs systems and IDA-based collapse ductility spectra of CBFs are concluded in this study. Variable periods range of CBFs systems considering reserve capacity are determined based on the IDA.

Abstract: In order to meet the growing needs of people, many buildings are used in special-shaped frame column, but because of the size and shape of special-shaped columns and other causes of concrete appearance quality is not high, by the QC group activity, cause analysis of special-shaped frame column concrete surface defects, and how to guarantee and improve the appearance quality of concrete special-shaped columns is proposed to solve the method, to eliminate the common quality defects of concrete surface and special-shaped columns.

Abstract: In order to avoid the failure of bond slip between the new and old concrete of the prestressed concrete composite slab (named PK slab), and the difficulty in the formwork of PK slab, this paper presents a new type of prestressed concrete composite slab with corrugated steel web (named PCCW slab). By using ABAQUS finite element analysis, it was found that the flexural behavior of PCCW slab was better than that of PK slab. Based on the analysis result, it could be seen that at the elastic stage, the flexural strength of PCCW slab increased with the raising of thickness of corrugated steel web, height of concrete flange, width of concrete flange and hole space of corrugated steel web. Among those effects of parameters, the thickness of corrugated steel web and the height of concrete flange were important.

Abstract: Based on Ježek method of computing the elastic-plastic buckling of the member under the axial compressive load and the bending moment, considering the initial imperfection, the analytical expressions of calculating the ultimate load of buckling about the neutral axis with the maximum moment of inertia for a square steel tube member are derived. Using the elastic-plastic finite element method and the theory of nonlinear buckling, the impact by initial geometric imperfections on the square steel tube member under the axial compressive load and the bending moment are analyzed and the numerical solutions of ultimate bearing capacity are obtained. By compared with the values of the finite element method (FEM), it shows that the analytical method in this paper is valid. The results of the example show that the presence of initial imperfections reduces the ultimate bearing capacity of the steel member to a great extent. It is also found that the influence of the initial geometric imperfection on the ultimate bearing capacity of member is smaller when the M increases.

Abstract: Based on Ježek method of computing the elastic-plastic buckling of the member under the axial compressive load and the bending moment, considering the initial geometric imperfection, the analytical expressions of calculating the ultimate load of buckling about the neutral axis with the maximum moment of inertia for a square steel tube member with flange outsides wrapped by carbon fibre are derived. Using the elastic-plastic finite element method and the theory of nonlinear buckling, the impact of the initial geometric imperfection on the square steel tube steel member wrapped by carbon fibre under the axial compressive load and the bending moment are analyzed and the numerical solutions of ultimate bearing capacity are obtained. By compared with the values of the finite element method (FEM), it shows that the analytical method in this paper is valid. Compared the reinforced effect of the carbon fibrer to the perfection member with the defect member, we find that the former is higher than the latter. The results of the example also show that the presence of initial geometric imperfection reduces the ultimate bearing capacity of the steel member to a great extent. The influence of defect member gradually decreases when the given moment rises.