Applied Mechanics and Materials Vols. 351-352

Abstract: Debonding behaviors of CFRP strengthened RC beams were experimentally investigated under the influence of weak interfaces, which are induced either by defective bonding of replaced cover or expansive cracks. Shown by test results, weak interfaces impaired considerably the structural integrity of strengthening systems during loading, and easily led to CFRP debonding failure. U-strips worked effectively in preventing the integral debonding and guarantee the structural performance of flexural sheets. However, local cover delamination in the loading process and premature rupture of flexural CFRP could still take place due to the weak interface effects. Therefore, allowable tensile strain of flexural CFRP should be reduced, and more strict confinement and anchorage measures should be taken in this case.

Abstract: The purpose of this paper is to focus on studying its flexural behavior after different damages prestressed concrete hollow slab is strengthened with CFRP.By the experimental method, twelve residential prestressed concrete hollow slabs are tested under concentrated force at the two points of the symmetrical load in order to analyze both flexural behavior and effects factored by different bonding modes.The conclusion can be drawn that the flexural behavior of prestressed concrete hollow slabs strengthened with CFRP is well-tried.It provides design suggestions and reference for prestressed concrete hollow slabs strengthened with CFRP, and also provides an experimental basis for the repairing and reinforcing practical engineering application in Wenchuan disaster area.

Abstract: The Wenchuan earthquake and Yushu earthquake indicated that the damage of large bay brick masonry buildings with fewer internal longitudinal walls, even no longitudinal wall in the sitting room was much heavier than the ordinary buildings. In order to study this damage phenomenon, the typical buildings were analyzed. (one is large bay building, another is ordinary building) The reserve coefficient of average shear capacity is used to evaluate the seismic capacity of the structure. The analytical results show that the safe reserve coefficient of the latter one is smaller, and easy to damage. Therefore, such building in earthquake zone should add the longitudinal wall in the sitting room to strengthen the local longitudinal stiffness.

Abstract: Cold-formed steel box-shaped section has the special features in both its mass center and moment center unification as double symmetry section and its outstanding advantage in moment and torsion rigidity. This paper presents a new kind of cold-formed steel box-shaped component welding sections, that is flanges opposite welding box-shaped component section DS. The mechanical properties such as buckling modes, load carrying capacity, rigidity, ductility and correlation curves of new section members which are subjected to axial compression, flexure, combined compression and bending have been analyzed by using nonlinear finite element method. The consumed steel quantities of per unit load carrying capacity between new section members and the same section dimensions of cold-formed C-section members have been compared systematically, too. Some conclusions can be drawn from above work that the DS section members have some superior properties, such as higher load carrying capacity and section modulus especially subjected to compression load, sufficient section stiffener and the sub-element local buckling hard to happen and so on. They are particularly suitable to withstand axial compressive loads, but also suitable to withstand the bending moment and bending loads. The consumed steel quantities are as almost 50% as the same dimension C-section members. The DS section members can go deep into the experimental study as to be used in the practical engineering.

Abstract: The concrete-filled steel shear wall with binding bars is a new kind of lateral force resisting structure, which assembles binding bars with certain spacing. The behaviors of the structure under axial compression, containing bearing capacity and ductility, are studied by the software ABAQUS. Some factors as length-width ratio, bar spacing, steel thickness and material's strength grade, are taken into account. The results show that the axial compressive bearing capacity factor λ increases with length-width ratio b/t increasing; the factor λ, the ductility factor DI and the vertical displacement decrease with bar spacing d increasing; the bearing capacity factor of steel plate λ_s and DI increase while the factor λ decreases with steel thickness t_s increasing; and with the concrete's strength grade and steel's strength grade improving respectively, both the factor λ and DI decrease. At the same time, the structures simplified formula under axial compression is presented.

Abstract: In order to analyze the mechanical properties of the remaining carrying capacity of steel reinforced concrete columns after exposure to fire, full preparations must be needed. In this paper, the numerical simulation of the temperature field of steel reinforced concrete column section was being adopted the finite element analysis software MSC.MARC to analyze. Temperature distribution law of the column cross-section in the case of uneven fire was obtained. There has a nice agreement between calculation and original test data which created the conditions for high temperature and high temperature performance analysis for SRC columns

Abstract: With the rapid development of high-rise frame-tube office buidings in domestic large and medium-sized cities, it brings the problem about the study of quantities. Traditional structural design can meet the requirements of all kinds of standards, but it wastes materials, which is now taken seriously. Structural optimization design can save materials. This paper carries structural optimization design on eight high-rise frame-tube structures, and proposes a predictive method for concrete and steel-bar dosage of high-rise frame-tube structures after analysis. The predictive method makes it possible to predict the dosage before the structural design without the tedious budget process. The predictive value is economical and reasonable, and it can provide reference for structural design and construction in the future.

Abstract: Static stability analysis to 12 kinds single-story steel frames with I-section columns is analyzed based upon bilinear lateral force versus displacement framework curve and finite element method, then ultimate displacements are obtained. In comparison, the framework curves and ultimate displacement calculated by modified stiffness and cross-section plastic moment theory accord with that calculated by finite element method. This provides the referential basis for the static stability analysis to a single-story steel frame.

Abstract: One of the most important factors that may cause a buried steel pipeline to reach the failure limit is the permanent ground displacement. In this paper, assuming SHELL element for pipeline and SOLID element for soil and also considering the interaction of pipe-soil, analysis of buried pipelines crossing fault and parametric study of pipeline behavior were performed. The results of this study show that the behavior of buried pipelines crossing fault is not sensitive to the pipe-fault crossing angle. The main reason for this is the immense strain of the pipe due to the section deformation and local buckling of the pipe body that is caused by the permanent ground displacement. The strain from this phenomenon is so great that the pipe-fault crossing angle cannot have much effect on it. The research also shows that it is better to consider pipe bending than dealing with the pipe-fault crossing angle, because it is a more important parameter in the behavior of buried pipelines crossing faults, and it has a meaningful relationship with the reached maximum strain in the pipeline.

Abstract: Parabolic trough solar thermal power generation technology is the most mature technology in the world, which is also the only commercial operation of the solar thermal power generation technology. In order to the structure characteristics of the collector was accurately simulated and the result was calculated to reflect the performance of collector, the whole model of collector established. The internal force and deformation of steel under the external load was analyzed by nonlinear finite element method. For the connection problems of rectangular frame and mirror of the collector, the strength and rigidity of collector mirror were calculated by the finite element software for ANSYS, Which circular shaft for collectors steel production process complex, transportation inconvenience, put out by rectangular frame instead of round axis, ANSYS finite element software to rectangular steel collectors strength and stiffness calculation, and the standard comparison, and to provide a useful reference for large-scale production of the solar Collector.