Advanced Materials Research Vols. 671-674

Abstract: Recently, high-performance steel has been increasingly used for structural materials in buildings and bridges with the demand for high-rise and long-span of main structures. This paper is a series of basic study for the design specification of structural members using high performance steel, material properties of HAS800(High-performance rolled Steel for building structures). HSA800 was compared with the requirements of Korean Standards(KS). Built-up box stub columns with variables of width-to-thickness ratios are planned in order to investigate the local buckling behaviors and check the current design limit of width-to-thickness ratio. In addition, the buckling behaviors of stub columns obtained finite element analysis were compared with those of test results.

Abstract: Anti-slide pile was widely used in the slope-sliding control，based on the traditional Anti-slide pile, a kind of high efficiency and good effect new slope anti-slide pile-Buttress Anti-slide Pile-was put forward,which changed the cantilever stress condition and the mechanism of depending entirely on lateral subgrade reaction to balance the landslide thrust of the traditional anti-slide pile, and the theoretical calculation formula is deduced.

Abstract: All-bolted steel beam-to-column connections for concrete-filled square steel tube (CFST) have the advantages of industry manufacture, being constructed quickly and easily concreting. The new design all-bolted connection discussed in this paper has the construction details of Π-shape plate and high strength bolts which connect the steel beam and CFST column. In order to investigate the static performances and failure modes of this new all-bolted connection, a full three-dimension ANSYS finite element (FE) model of the connection subjected to montonic load is built up. The theoretical values and experimental results are very close, that verifies the rationality of the FE models and the analysis method in this research. Further the calculated results demonstrated the new bolted connections belong to typical semi-rigid connection and have the superior static resistance in stiffness, strength, and rotating capacity.

Abstract: Based on nonlinear FEA software ANSYS, thirty-six numerical simulation tower-models that have different initial bend state, bend deflection and intersegment of main-rod were established. Analysis results indicate: Initial bend state of main-rod has influence to force of horizontal auxiliary-rod greatly. With increasing initial bend deflection of main-rod, force of each horizontal auxiliary-rod presents to enlarge trend and is unequal. Force of each horizontal auxiliary-rod is less than 0.015 times endogen force of main-rod, total of each force for horizontal auxiliary-rod is less than 0.06 times endogen force of main-rod. With increasing intersegment of main-rod, total of each force for horizontal auxiliary-rod presents to enlarge trend.

Abstract: The damage and failure of reinforced concrete (RC) slabs under blast loadings may cause significant hazards for frame systems even progressive collapse of whole structures. The numerical simulation of one-way RC slabs using the finite element explicit code LS-DYNA to estimate the dynamic response and failure mode of one-way RC slabs .Blast loadings are imposed on the top surface of slabs using a blast model based on conwep algorithm. Concrete was modeled using a concrete damage constitutive model considering strain rate effect, and reinforcement was modeled using a elastoplastic material type with kinematic hardening and strain rate effect. The numerical model is introduced in details and adopted to simulate the dynamic responses of RC slabs in reference test. The numerical model can match well with the test data, and thus the proposed numerical model can be considered as a valuable tool in assessing the deformation or failure mechanism and predicting the dynamic responses of one-way RC slabs subjected to blast loadings.

Abstract: For investigating the stiffness changes on reinforced concrete beam at different level of corrosion after fatigue, a group of RC beams were designed with different corrosion ratio, and fatigue test was carried on these specimens. The deflection, strain and crack of these specimens were analyzed in fatigue loading. The results indicate that the effect of corrosion ratio on fatigue performance of RC beams is very obviously.

Abstract: This paper reports a finite element analysis of the axial compressive behaviour of concrete-filled steel tubular slender columns with elliptical section. A set of test data were used to verify the FE modeling. Typical curves of axial load (N) versus deflection at mid-height (um), as well as stress distributions of steel tube and concrete of the composite columns were compared and discussed. The results clearly show that the FE model is available for predicting the load-bearing capacities and the failure modes of the specimens.

Abstract: A probabilistic model of the chloride-induced corrosion process is provided in this paper. Based on the Third-moment method, the uncertainty of various influence factors and the coupling effects of them are concerned. Considering the corrosion process as a statistic process, the probability of corrosion initiation at certain time can be obtained. Moreover, the effect of micro-crack in chloride ingress is taken into account, too. Due to the results of stochastic analysis, the surface chloride concentration is the most important factor that affects the corrosion probability, while the thickness of concrete cover, chloride diffusion coefficient, environmental relative humidity, critical threshold chloride concentration, micro-crack rate, water-to-cement ratio and temperature are also important factors. And the Third-moment method is proved to be reasonable in the durability assessment of corrosion-induced concrete structure. The results in this paper can be used to predict the rest life of corrosion-induced concrete structures.

Abstract: In order to ensure the safety of production, a new method for strengthening pipe with carbon fiber reinforced polymer sheet is introduced. The experimental research on the effect of this method has also been done. In the experiment, the pipe that wrapped with one and two layers of CFRP sheets respectively are tested. And the relation between the hoop strain in the tested pipe and the internal water pressure is given according to the experiments. The results show that it can be a substantial increase in the bearing capacity of the pipes. The construction of this method is simple and a short period is required; so it not affect the normal operation of generating unit. It has a good practical value in the production practice.

Abstract: The snow load of a space truss structure subjecting is unevenly distributed after snowstorm disaster, which caused uneven forcing and local damage of the members and roof purlin of the original space truss. The damaged members and roof purlins were strengthened and replaced in loaded condition in order to guarantee the space grid structural safety. The results during the construction process have shown that the presented strengthening plan is successful, which can provide us a good reference of the similar projection.