These days, the Composite Slabs with Deep Deck plate was commonly used in domestic construction site, and, the application of the Slim Floor system was increased from the Enlargement and High-rise Building. But, Slim Floor system using the Deep Deck was shown safety problem caused by the deflection and local buckling in construction phase when used to more than 6m. Therefore, for solving the problem, the installation of the shores is essential. This study is realize the long span slab without shores from control the deflection through applied the pre-tensioning elements in CAP deck. In addition, by applying the pre-tensioning member as the tensile member of the CAP Deck slab, the pre-tensioning member for the shores tries to be used as the structural member. Accordingly, to determine the flexural performance of the CAP Deck slab through the pre-tensioning force in tensile member, and, the composite effect of the CAP Deck slab by the experiments.
Cap decks used in slim floor system for reducing floor height act as molds for forming floor slabs in structures with a span of up to 6m without temporary supports. When deep decks are employed in a structure with a span of more than 6m, the problem of defection occurs. This study suggests placing tendons at the ends of cap decks in order to create cambers and control defection when preload is applied. Uniformly distributed load was applied by an UTM to the two L/4 points of specimens to observe the deflection of preloaded cap decks. For the test, three 7.5m specimens were fabricated. One of them was a plain cap deck specimen and the others were those with tendons (PC strands or steel bars.
As a preparation of a design standard regarding road facilities, such as cantilever columns for traffic lights, optimum design and risk assessment for foundation of street lights on highways are proposed. The preliminary evaluation of optimization with reliability assessment resultantly makes it possible to reduce not only the duration of construction but the cost of construction as well. Ultimate limit states and constraints functions are selected for the sliding, overturning and settlement of the foundation under external loads from super and sub-structures itself. An example foundation under the super structure of height 12m, is optimized as 30% decreased embedded depth of foundation, in which as increasing the depth of embedded connection parts, the necessary depth of foundation is deceased. However, the optimum depths and the reliability indices are sensitively dependent with earth properties and dimensions of foundation.
This study deals with optimized structural analysis of stainless rectangular water reservoirs with 5,000ton capacity for various combined load cases. The objective of this study is to propose most efficient structural models through the comparison of various model cases. In order to perform an optimized analysis, three dimensional finite element analyses are carried out for large sized models. The numerical results obtained provides the detailed size and thickness for optimal design of water reservoir. In particular, results reported in this paper show the influence of various types of loading and dimensions of the wall and stiffened column on the structural behavior of the large sized water tanks.
This study carried out fiber damage detections of laminated GFRP plate structures using a modified bi-variate Gamma function. The effects of different layup sequences of composites on the fiber damage detection are studied using the finite element commercial package and genetic algorithm. Four unknown parameters are considered to determine the shape of the damage distribution, which is a modified form of the bivariate Gamma density distribution function. The sample studies show the excellence of the proposed method from the standpoints of its computation efficiency as well as its ability to determine the complex shape of an arbitrary stiffness degradation distribution.
Rail wear in a curved track costs significant amount of maintenance efforts every year. The rail wear is affected by such parameters as train speed, curve radius, and insufficient cant. However, while the effect of train speed and curve radius to the rail wear is relatively well-known, the effect of the insufficient cant has not analytically researched sufficiently. In this paper, the effect of the insufficient cant on rail wear is studied using a multibody dynamics program, the Vi-Rail. The multibody analysis is performed using an EMU train model being operated in the urban railway. The hard track is utilized in the analysis. To identify the relationship between rail wear and insufficient cant. the wear analysis is conducted for various train speeds and curve radius based on the Archard model built in the Vi-Rail program. The analysis result reveals that, as the insufficient cant increases, the vertical and horizontal wear of the outer rail increases, but the wear of the inner rail does not show distinct trend.