Applied Mechanics and Materials Vols. 166-169

Abstract: This research is aimed at evaluating pull-out capacity through the pull-out test of the reinforced headed bar, a mechanical anchorage, that can replace standard hook. The reason for the weak standard hook making congestion of bars of beam, which is a problem of the reinforced concrete beam-column joint so that it causes the stress concentration inside the joint. As the variables for this test, the hook type that anchored the reinforced headed bar at the beam-column joint, hoop-reinforced type, and the transverse reinforcement type were selected. The researcher analyzed fracture pattern of the test specimens regarding each variable, and the deformation pattern according to load as well. The results from the comparison of the specimens according to the type of laterally confined bar revealed that, though the type of longitudinal bar and of hoop reinforcement were identical, the yield and maximum load of the test specimen of which type of the laterally confined bar was a cross was high as much as 8% and 9% respectively.

Abstract: To overcome the inadequacy such as the low stiffness, the weak shear capacity, brittle failure and the big initial cost in all FRP box beam, and to make use of the benefits of steel such as the high stiffness, the strong shear capacity, good ductility and the low cost, a new type of GFRP/steel composite box beam was proposed. A given GFRP box beam was used to investigate the effects of adding steel volume ratio (the ratio of steel volume to the total volume in the adding section) on the performance of the GFRP box beam by theoretical calculation, and the adding sections of steel plates for GFRP box beam included top and bottom flanges, and all cross-section, respectively. The analytical results indicate that the performance of GFRP box beam increases dramatically and the cost of beam remains almost unchanged after adding steel plates. At the same time, the performance of GFRP box beam is obviously more excellent by adding steel plates into the all cross-section compared with top and bottom flanges.

Abstract: A space numerical model about 1000MW turbo generator foundation of a power plant is established by ANSYS software, meanwhile analyzing the model’s vibration characteristics and response under the turbo generator working conditions. According to the existing norms, optimizing the foundation based on the linear displacement amplitude control, furthermore researching the corresponding dynamic on the optimized foundation for guidance to structural design.

Abstract: This paper reviews research on the large deflection of the orthotropic and rectangular membrane under the distributed load. Through building the theoretical model of the orthotropic and rectangular membrane under the distributed load, the authors deduce the equations set of the membrane which has the effect of pretension and solve the equations set with the perturbation method. The authors obtain the relational expression between the maximum deflection of the membrane’s centre point and the external load, then make a comparison between the large deflection and the small deflection. At last, With the example, the authors analyze the change of the deflection of the centre point of the membrane along the external load, and the length of the side, and the large or small of the pretension and other parameter.

Abstract: Unreinforced stone masonry pagodas have great cultural value and should be detailed investigation its mechanical properties. These buildings were not designed to resist earthquakes in ancient China, at least not in the way of current methods. The objectives of this research were to understand the dynamic behavior of unreinforced stone masonry pagoda and its seismic performance. To accomplish these, a 1/12 scale model of China Dinosaurs Pagoda was constructed and tested on shaking table. The octangle model height is 3.96m, with aspect ratio of height to width is 2.93, both parameters exceed the stipulated limit of Code for Seismic Design of Building. The model built with the stones and motars similar to the prototype materials and the arrangements. Its dynamic behavior and seismic performance were tested on the shaking table towards the free vibration and three earthquake waves. The experimental program adopted in the research is explained in this paper.

Abstract: Three level and two stage design method is the main seismic design of China, which has continued to use until now. However, the design method lacks specific quantitative performance index of the Reinforced concrete (RC) structure. Comparing with the present internationally advanced performance-based seismic design method, the design method has still a certain gap. In order to develop the performance-based design method at domestic, it is necessary to carry on the refinement to China's performance level of RC structure and quantify essential performance index under different seismic level. In the paper, seismic levels are divided into four seismic levels performance levels of RC structure are divided into four run phase. And then, the story drift angle limit of RC structure in the four run phase is quantified.

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 an H-shaped 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 H-shaped 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.

Abstract: Based on the geometric characteristics of developed cylinder shell, five methods of node generation and element connection were proposed in the cylindrical coordinate system. The corresponding macro programmers were made by means of ANSYS software parametric design language. Five developed cylindrical shell parametric modelings were achieved under the conditions of the given shell types, span, vector height, length, the grid number of length wise direction and cross wise direction. Applied examples show that this parametric modeling method and programmers are simple, efficient and useful, which facilitate the force analysis and optimizing design under different types and parameter by means of ANSYS software.

Abstract: Based on the structure features of double primary ribs reticulated domes, a method for node generation and element connection of six typical double primary ribs reticulated domes was produced in spherical coordinate system. A macro program was designed by using ANSYS Parametric Design Language (APDL). This six typical double primary ribs reticulated dome modeling was realized under given parameters such as span, rise high, double primary ribs thickness, grid number in circular and radial direction. It is proved by several examples that this method is simple, efficient and possible. It can be easily used to analyze the internal force and optimized design in shell structures.

Abstract: According to the seismic demand spectra form the code for seismic design of buildings, seismic performances of eccentrically braced steel frames (EBF) in frequently, fortification and seldom occurred different intensity earthquakes were evaluated by the Capacity Spectrum Method (CSM). The capacity curves derived from base force-top displacement curves of structures subjected to the lateral seismic load of seismic codes were obtained from pushover analysis by applying sap2000 software and transformed to the spectrum curves, seismic performance were evaluated according to the intersection between the seismic demand spectra and the capacity spectrum. Seismic performances of 15 EBFs designed according to the Chinese design codes were evaluated by CSM. The certain ductility and displacement capacity of EBF in accordance with the China corresponding design codes are shown and some reference is suggested.