Applied Mechanics and Materials Vols. 578-579

Abstract: The influences of high mode effect on ductility reduction factors for multi-degree-of-freedom (MDOF) systems are studied by modifying ductility reduction factors for equivalent single-degree-of-freedom (SDOF) systems. Based on MDOF lumped-mass shear-type models, nonlinear dynamic time history analysis are performed to investigate the influence of ductility demand increase owing to high mode effect on ductility reduction factors. An empirical estimating model of MDOF modification factor is proposed. The results demonstrate that ductility reduction factors for MDOF systems are clearly smaller than those for SDOF systems. The modification factor is mainly affected by the fundamental period and ductility.

Abstract: To study on the property of the column to wall connection in the prefabricated frame-shear wall structure, these four connection ways are introduced in the article, which are U-shaped ,double straight ,chain buckle, double straight vertical U-shaped bar splicing. Using ABAQUS to simulate, comparing results of four connection ways with the cast-in-situ concrete structure. The results show that mechanical properties of four prefabricated structures are similar to the cast-in-situ structure, but the maximum bearing capacities are reduced.

Abstract: For the study of column-wall connection technology of precast frame-shearwall structure system, four practical connection methods of wall-column subassembly in precast frame-shearwall structure were proposed in this paper. Based on the general finite element software ABAQUS, numerical simulations were carried out on the mechanical performance of the precast and cast-in-situ wall-column subassembly. Results showed that mechanical performance of the precast column-wall subassembly, such as carrying capacities, deformations and failure modes, was almost equal to the cast-in-situ wall-column subassembly. Feasibility of the connection method which this paper proposed is verified preliminarily. The research results can provide theoretical references for related experimental researches, engineering designs and constructions.

Abstract: Wind-induced aerodynamic force is the important parameter for transmission tower design. Based on force balance test, the tower and cross arm of typical 500kV power transmission tower have been investigated in wind tunnel using three wind speeds considering Reynolds effect. The test results show that the shape coefficient keeps the same at different wind speed, which means that Reynolds effect on transmission tower can be ignored. Then, the shape coefficients of tower and cross arm are provided.

Abstract: The rung-shape long-span tensile cable-membrane structure in Foshan Century Lotus Stadium was analyzed. The effects of different pre-stressing degree and membrane tensile rigidity were discussed on structure natural vibration, static wind loads response and wind-induced dynamic analysis. Dynamic wind equivalent coefficient which can be used in structural design was also preliminary analyzed.

Abstract: Geopolymer concrete is an emerging construction material that uses a by-product material such as fly ash to completely replace the ordinary Portland cement. This material is being studied extensively and shows promise as a greener substitute for ordinary Portland cement. This paper evaluates the bond strength and development length of reinforcements embedded in geopolymer concrete with reinforcing steel using pull-out tests. The test according to EN 10080 was carried out on 27 specimens for three kinds of geopolymer concrete of 20, 30 and 40 MPa compressive strength and 10, 16 and 35 mm diameter reinforcing bars. The tests show that the bond strengths in geopolymer concrete were decreased as the diameter of reinforcement increased as in ordinary concrete and the values were greater than those in ordinary concrete. Also, the bond-slip curves were obtained which have similar shape with those of ordinary concrete. The equation for the determination of development length based on this experiment was proposed.

Abstract: The main idea of this paper is to present a smart numerical technique to solve structural and non-structural problems in which the domain of interest extends to large distance in one or more directions. The concerned typical problems may be the underground excavation (tunneling or mining operations) and some heat transfer problems (energy flow rate for construction panels). The proposed numerical technique is based on the coupling between the finite element method (M.E.F.) and the infinite element method (I.E.M.) in an attractive manner taking into consideration the advantages that both methods offer with respect to the near field and the far field (good accuracy and sensible reduction of equations to be solved). In this work, it should be noticed that the using of this numerical coupling technique, based on the infinite element ascent formulation, has introduced a more realistic and economic way to solve unbounded problems for which modeling and efficiency have been elegantly improved. The types of the iso-parametric finite elements used are respectively the eight-nodes (Q8) and the four-nodes (Q4) for the near field. However, for the far field the iso-parametric infinite elements used are the eight-nodes (Q8I) and the six-nodes (Q6I).

Abstract: This paper briefly introduces methods of buckling analysis, develops a model of single-layer reticulated shell in SAP2000 and carries out buckling analysis of it, using ABAQUS. The results in this paper can be recommended for practical engineering analysis of grid structures.

Abstract: The lightweight frame structure with Multi-ribbed slab is a new energy-efficient residential architecture. The Multi-ribbed composite wall of the frame structure plays an important role as the main bearing components. This paper mainly discussed the mechanical performance of composite wall. A simplified frame-plane model was built based on the theoretical analysis of the composite wall. The professional calculating program has been designed and written by FORTRAN, and the calculation and analysis of the typical model has been completed with the program. Finally, the frame-plane simplified model was further calculated and analyzed by ANSYS. The method used in this paper may open a new approach for simulating and analyzing the mechanical performance in engineering practice and the result we got may provide some theory basis for the application of Multi-ribbed slab frame structure.

Abstract: This study examined the compressive behaviors of concrete with artificial sand that mixed with different content of stone powder (SP). Forty-five cubic specimens were prepared with two strength grades and five SP-content. Including 15 specimens (C35) of recycled coarse aggregate (RA) concrete with artificial sand (RCC35), 15 specimens (C45) of recycled coarse aggregate concrete with artificial sand (RCC45) and 15 specimens (C35) of natural aggregate concrete with artificial sand (NC35). The workability of concrete mixture and the compressive strength of the cubic specimens were tested. The results showed that the slump of concrete mixture decreased with the SP-content increased, and the coagulability and water retentivity of the concrete mixture were improved by using stone powder. The compressive strength of the concrete with artificial sand were increased by incorporating stone powder. The optimal SP-content of RCC35 and NC35 is 20%, while RCC45 is 10%.