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Full-Text Articles in Engineering
Spectral Analysis Of Train-Rail-Bridge Coupling System Considering Frequency-Dependent Stiffness Of Rail Fastening Systems, Linya Liu, Jialiang Qin, Quanmin Liu, Jong-Dar Yau, Rui Song
Spectral Analysis Of Train-Rail-Bridge Coupling System Considering Frequency-Dependent Stiffness Of Rail Fastening Systems, Linya Liu, Jialiang Qin, Quanmin Liu, Jong-Dar Yau, Rui Song
Journal of Marine Science and Technology
A rubber rail-pad is typically inserted between the rail and the sleeper to attenuate wheel/rail vibrations for conventional train-rail-bridge (TRB) system. For mathematical modeling, a rail-fastener with rubber pad is simplified as a spring-dashpot unit, whose spring stiffness is related to the exciting frequency of external loads. To exhibit such characteristics of rail-pads on TRB dynamics, based on dynamic flexibility method, two computational models of constant/frequency-dependent stiffness (FDS) are considered for comparison. Numerical studies reveal that the FDS model provides a strengthening benefit for the wheelrail vibration, from which the shifted dominant frequencies in spectral response are observed.
Influence Of Fly Ash Fineness And High Replacement Ratios On Concrete Properties, Shihwen Hsu, Maochieh Chi, Ran Huang
Influence Of Fly Ash Fineness And High Replacement Ratios On Concrete Properties, Shihwen Hsu, Maochieh Chi, Ran Huang
Journal of Marine Science and Technology
The influence of fly ash (FA) fineness and a high cement replacement ratio on concrete properties was investigated. Class F FA with an original fineness of 3,150 cm2 /g (3F) and a high fineness of 5,690 cm2 /g (5F) was used; high cement replacement ratios of 30%, 40%, 50%, and 60% by FA with different levels of fineness (two groups: 3F30, 3F40, 3F50, 3F60, and 5F30, 5F40, 5F50, 5F60 by weight of cement) were selected to produce the blended cement concrete. Tests regarding the heat of hydration, compressive strength, water absorption, rapid chloride penetration, and Mercury intrusion porosimetry were performed. …