Applied Mechanics and Materials Vols. 764-765

Abstract: A method of establishing a kinematic model for simulated railroad freight car impact based on the Runge-Kutta method is introduced in this paper. The model is solved based on numerical analysis to obtain the relationship of variables, furthermore providing a basis for determining the loading support and loading securement method.

Abstract: For safe and efficient use of the Perfobond Rib shear connector, it is essential to investigate mechanical behaviors and evaluate performance of shear resistance. When the Perforbond Rib shear connectors are to be used for a structure, they show flexural-shear behavior due to external force rather than direct shear behavior. Therefore, this study performed a direct shear test and proposed the equation for the shear resistance assessment. Also, a flexural shear test was conducted. Through the direct shear test, main factors that affect directly shear resistance were found. The flexural shear stress and the direct shear stress were calculated and it is revealed that the flexural shear stress is approximately 6% stronger than the direct shear stress.

Abstract: The Shin Kong Tower located in Taipei City has a height of 244.15 m. It was the tallest building in northern Taiwan when it was built in 1993. This super tall building is susceptible to severe vibrations induced by strong winds. The safety of building structures and contents as well as the comfort of occupants under such strong forces as typhoons remain a major engineering concern. In order to improve our understanding of building structural responses, records of a structural array in the 51-story SK Building in Taipei from the Typhoon Aere are analyzed. In addition, wind data measured at the Taipei Meteorological Station are also used. As a result, the measured data during Typhoon Aere show that the standard deviation of acceleration response at top of the SK Building increases with a power of 2.275 of the wind speed in the longitudinal direction, and a power of 2.302 of the wind speed in transverse direction. It is also observed that the acceleration responses in the transverse direction were generally larger than those in the longitudinal direction during the typhoon. This is mainly due to greater stiffness of the building in the longitudinal direction than the transverse direction. Furthermore, the field measurement data clearly demonstrate that serviceability of the SK Building met the criteria for occupant comfort during Typhoon Aere.

Abstract: In the recent construction industry, Fiber reinforced polymers (FRPs) have been considered to be an innovative material to repair and strengthen damaged structures. It is because FRPs have many beneficial characteristics, such as corrosion resistance, a high tensile strength-to-weight ratio, non-conductivity and design flexibility. As a demand of FRPs has increased, many researches on behavior of the structures which were externally strengthened with FRPs have been conducted. However, researches on time-dependant behavior of the structures have not been conducted yet. In order to provide improved serviceability to reinforced concrete (RC) members, the behavior of the RC members strengthened with FRPs under sustained loads should be investigated. This paper presents a series of long-term experiments and deformation-recovery experiments. For the long-term experiments, three RC beams were fabricated and two of the beams were strengthened with a carbon fiber reinforced polymer (CFRP) plate and a glass fiber reinforced polymer (GFRP) plate respectively. The beams were placed under sustained loads for about 550 days. After the 550 days, all of the beams were unloaded for the measurement of deformation recovery. The deflection and strains of rebar and FRP reinforcements were measures for about 60 days. As the result of long-terms experiment, the beams strengthened with CFRP plate showed a better performance in terms of deflection and strains of rebar and CFRP plate. Moreover, the beam with CFRP plate showed a higher deformation recovery and residual strength than the other beams.

Abstract: A series of grouped-model piles (2×2) centrifuge shaking table tests at an acceleration of 80 g was conducted to simulate seismic responses of a grouped-piles embedded in liquefiable sandy soil subjected to different magnitudes of earthquake loading. The tested grouped-piles connected with a pile cap are used to support 4 sets of model dry storage tank.Different test conditions including elevations of pile cap, elevations of ground water table, and dry and saturated sand beds all are reported in the study. Sensors (i.e., strain gauges along the depths of pile for measuring the bending moments, accelerometers for measuring the accelerations at different depths, LVDTs and pore water pressure transducers) densely instrumented in the piles and the surrounding soils provide valuable information for examining their evolution at various degrees of liquefaction. The magnitudes of bending moment along pile depths would increase with the increases of base shaking. The lowest bending moments were measured for the grouped–piles with the pile cap embedded in the dry sand bed while the largest lowest bending moments for the grouped–piles with the pile cap embedded in the saturated sand bed with the water table at the surface. The test results can be used to validate the results derived from the numerical simulation.

Abstract: The setup programme of dry storage of using spent fuel is that transportable storage canister (TSC) packing by using spent fuel placed in vertical concrete cask (VCC), then conveyed VCC from plant to site and put concrete pad. After VCC is in position, place the add-on-shell (AOS).This research analyses and simulate the behavior of VCC and AOC during earthquake by LS-DYNA which is dynamic transient structural analysis of finite element method. The main issue is the shaking response of VCC under earthquake while there is a hump on the bottom floor. From the result, the perturbation of dynamic stability of VCC and AOS have been occurred when the hump existed onto the floor. The construction specification of VCC/AOC bottom flatness should be considered

Abstract: This work proposes a simple and efficient approach to locating the storeys whose stiffness change in the life cycle of a structure. The storeys that may be damaged are determined by comparing the unitary stiffness matrix in different stages in the life cycle of a building. An appropriate ARX (autoregressive with exogenous input) model of structure in established from the structural dynamic responses in terms of acceleration or velocity. The parameters in an ARX model are identified through the short time Fourier transform, and the natural frequency and damping ratio of structure are estimated directly through these identified parameters. The effectiveness of the proposed procedure is verified using the numerically simulated earthquake acceleration responses of a six-storey structure that is damaged at one or two storeys. The proposed scheme is compared to the DLV approach (flexibility-based damage locating vector approach) in identifying damage storeys.

Abstract: In recent years, especially after typhoon Morakot, extreme torrential rain has resulted in large amounts of landslides in Taiwan. Debris that accumulated downslope blocked the drainage way and induced debris flow very often. The large amount of debris transported to wild creeks downstream may caused elevated riverbeds and channel siltation. All nearby villages and utilities are under this threat. The cleanout work of aggregated debris is of great priority after a disaster. In processing the cleanout work for wildcreek, debris can be treated as useful resources. This is very important in the watershed management and rehabilitation work. In solving the debris blockage problem, cleanout of debris so as to recover the drainage capability of watershed and at the same time, use the earth material to form the protecting measures can meet the carbon reduction requirement. Cleanout of the debris can be used in filling low-lying land in the upstream catchment area. By applying feasible methods to improve engineering properties of the debris can be used to make a variety of protective measures, to resolve the loss of land, roads, damaged buildings and other issues. In planning, the first is to consider the location and the protected object, etc., can be planned establish of embankment, bank protection, slope protection, and berms.

Abstract: The article deals with diagnostics of a historical bridge using measuring methods and inverse analysis and presents selected results of the pilot project implemented for the Railway Infrastructure Administration, state organization. The main task is to fulfill the function of an owner/operator of the national and regional railway owned by the state in Czech Republic. Main results of the project will be used for the reconstruction of the similar historical bridges on railway lines in the Czech Republic. Non-geodetic measurements include the determination of actual module of elasticity of the masonry, which was determined by direct measurement of the selected bridge support. Geodetic measuremets include long-term (seasonal epochs) and short-term (continuous during the load test) monitoring of geometrical deformations of the “Křenová” historical railway bridge construction in Brno.

Abstract: This paper presents design of a novel submerged Kuroshio generator system (SKGS) which is suitable for maritime environments near Keelung Sill. The SKGS was combined with a reliable cable design and a simple anchor system at sea, and it could ignore changes of yaw and roll motion through a proper rudder design. An intuitive simulation method adopted MapleSim software to create a rigid structure modeling of the SKGS. Different modeling frameworks for varied cable design and joint positions were adjusted to meet with the system requirements. Therefore, the system requirements of stability, dynamic equilibrium analysis, and motion behavior of the SKGS combined with the cable design were achieved in this study. Furthermore, the motion ranges of surge-axis and heave-axis could be converged within 0.5 m, and the estimated output power of the SKGS could exceed in 55.1 KW.