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Full-Text Articles in Engineering
Constraint-Type Fictitious Time Integration Method For Solving Non-Linear Multi-Dimensional Elliptic Partial Differential Equations, Yung-Wei Chen, Chein-Shan Liu, Yen-Shen Chang, Jiang-Ren Chang
Constraint-Type Fictitious Time Integration Method For Solving Non-Linear Multi-Dimensional Elliptic Partial Differential Equations, Yung-Wei Chen, Chein-Shan Liu, Yen-Shen Chang, Jiang-Ren Chang
Journal of Marine Science and Technology
In this paper, we propose a constraint-type fictitious time integration method (FTIM) for solving multi-dimensional non-linear elliptic-type partial differential equations. Based on the variable transformation of FTIM, the original governing equation is transformed into a new parabolic equation of an evolution type by introducing a space-time variable, and a new time integration direction is obtained. However, the space-time variable depends on the governing equation, boundary condition and fictitious time variable, especially due to the nonlinear effect. Previous studies have not discussed the definition of these nonlinear parameter problems, which may result in severe numerical instability and inaccuracy. To completely overcome …
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. …