Advanced Materials Research Vols. 163-167

Abstract: Thermal stresses and deformation in straddle track girders can be significant in comparison to dead or live load responses. In present paper, a comparison of current design-code provisions is present. The temperature distributions are obtained by a numerical technique for the solution of the Fourier heat-transfer equation and its boundary conditions. This technique is based on the finite-element method and takes into account the geometry of cross section of the track girder, thermal properties of concrete, and the climatic conditions. A field test is conducted on a track girder to verify the analytical models. The results of a temperature gradient study developed to evaluate design thermal vertical differences for the straddle type track girder are presented. The analysis suggests that straddle track girders are designed for larger temperature gradients than the codes suggested.

Abstract: The reinforced concrete single T-shaped beam is of common use. Compared with mechanical analysis, little attraction has been put on the stochastic optimized inversion problem. The present study is aimed to carry out stochastic optimized inversion of mechanical parameters of reinforced concrete single T-shaped beam based on degraded solid element theory. Firstly for the reinforced concrete single T-shaped beam, degraded solid element theory is deduced and the displacement function is obtained. Then Gaussian error function of mechanical parameters of the reinforced concrete single T-shaped beam is founded and the corresponding formulas of Gaussian expectation and variance are derived. The stochastic optimized inversion computing formulas are also obtained by adopting optimization method including conjugate gradient method. Then the steps of stochastic Gaussian optimized inversion of mechanical parameters of the reinforced concrete single T-shaped beam are listed. Through analysis of a classic example, some important conclusions about stochastic Gaussian optimized inversion of mechanical parameters of the reinforced concrete single T-shaped beam are drawn.

Abstract: In order to investigate the seismic performance of recycled concrete perforated brick masonry, an experiment was conducted on three specimens of recycled concrete perforated brick walls subjected to low frequency reversed cyclic load test. The loading process, failure mechanism, ultimate bearing capacity was studied. The seismic behavior such as hysteretic characteristics, backbone curve, ductility, energy dissipation capacity were analyzed too. The test results show that the seismic performance of recycled concrete perforated brick masonry is similar to those of ordinary concrete perforated brick walls. The test results also indicate that the seismic behavior of recycled concrete perforated brick masonry is good. The specimens have good hysteresis loops and ductility, strong energy dissipation capacities.

Abstract: Based on the equivalent uniaxial stress-strain relationship for the encased concrete in the square steel tube with binding bars, the fiber element analysis technique is used to conduct the load versus curvature curves for the square concrete-filled steel tubular (CFT) stub columns with binding bars subjected to eccentric load, and the results predicted by the program agree well with the experimental ones. The fiber element analysis program developed is then used to investigate the effects of varied parameters on the curvature ductility of square CFT stub columns with binding bars subjected to uniaxial or biaxial eccentric load, and the corresponding simplified formulas to predict the curvature ductility of the columns are put forward, respectively. The results predicted by the simplified formulas agree well with those predicted by the program.

Abstract: The mechanical behavior of 12 concrete specimens under local strain is studied according to simulating principle of work of gate slot. The experimental result indicates that the failure mode of these reinforced members in the test has revealed to be shear failure. The shear failurelaw of gate slot based on the test data is analyzed in the paper, and the main effect factors of the shearing capacity of gate slot are discussed. In this foundation, a corresponding proposed simplified method is put forward in the end.

Abstract: In this research, a CFT column connection with vertical plates is proposed, and studied through a finite element model. For this purpose, three-dimensional finite element models are constructed by a general purpose finite element code, ABAQUS. Comparing the results of the models indicated the effectiveness of the proposed vertical plate scheme in reducing story drift, increasing the shear strength of the panel zone.

Abstract: In engineering, the excessive slip of shear connectors will arouse the failure of the beams, and cracks in the brittle material element can increase the slip. In this paper, composite beam is composed of the brittle and ductile material elements and there are cracks in the brittle material element. Based on the relation between the slip strain and flexural rigidity, defining rigidity coefficient as there are cracks in the brittle material element, the total change in the slip strain at a given section due to cracking of the brittle material is obtained. The end slip that incorporates the effects of the brittle material cracking is calculated by integrating the slip strain. Letting the end slip equaled to the ultimate slip of shear connectors, the ultimate load formation of composite beam is gotten.

Abstract: A novel integral noise barrier (INB) composed of steel fiber reinforced cementitious composite (SFRCC) and basalt fiber reinforced plastic (BFRP) is put forward in this paper. Compared with traditional noise barrier, INB integrated sound-absorbing panel, H type steel, autoclaved lightweight concrete (ALC) bridge guardrail panel into a whole. The basic design idea and experimental method for INB are described. Based on the engineering demand for eastern extension project of the No.2 subway line of Nanjing, six specimens were cast and tested under simulated positive and negative loads. Under the design loads, six specimens did not crack and the lateral displacement on the top of the slab is less than H /250, where H is the height of INB. The experimental results show that INB can meet the design requirements of eastern extension engineering of the No.2 subway line of Nanjing.

Abstract: In order to better understand the behavior of CFST-CSW arch, experiment on two hingeless CFST-CSW arches are described in this paper, subjected to in-plane symmetrical and asymmetrical loading respectively. The experiment yield important information regarding the manifestation of the limit state and also afford an opportunity to verify finite element modeling techniques for use in a parametric study. The parametric study reveals that the load-carrying capacity is influenced by many factors including the rise-to-span ratio, slenderness ratio, loading cases and material properties.

Abstract: Consistent Mode Imperfections Method based on eigenvalue buckling mode is widely adopted in the stability analysis for the spatial steel structures with initial geometrical imperfections, i.e. latticed shells, thin shells, etc. Taking the new type hybrid structure of suspendome as the analytical object, the applicability of Consistent Mode Imperfections Method is discussed. The effects on structural stability are probed arisen by the factors such as different initial reference loads and different order eigenvalue buckling modes. It is indicated that this stability analysis method can be quite fit for the spatial structures such as latticed shells, while for suspendomes, the initial reference load has a distinct effect upon the analytical result obtained by the stability analysis method. Moreover, it is not always to dominate calculating result when selecting the first order eigenvalue buckling mode as the distributing pattern of initial geometrical imperfections. As a result, some measures should be taken to improve the accuracy in evaluating the stability bearing capacity of the structures with Consistent Mode Imperfections Method based on eigenvalue buckling mode.