Efficient non-stationary random vibration analysis of vehicle-bridge system based on an improved explicit time-domain method

Abstract Based on the explicit time-domain method in conjunction with the equivalent linearization technique, an efficient analysis algorithm is developed for the random vibration analysis of the coupled vehicle-bridge system with local nonlinear components under the random irregular excitation from a bridge deck. With the coupled vehicle-bridge system divided into two subsystems, the equivalent linearized subsystem for the vehicle subsystem with the hysteretic suspension spring is constructed for the given time instant using the equivalent linearization technique. Then the dimension-reduction vibration analysis for the equivalent linearized coupled vehicle-bridge system can be carried out based on the time-domain explicit method, which has been proven to be highly efficient. The numerical example indicates that the proposed approach is of feasibility.

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Explicit Time-Domain Approach for Random Vibration Analysis of Jacket Platforms Subjected to Wave Loads

Journal of Marine Science and Engineering ◽

10.3390/jmse8121001 ◽

2020 ◽

Vol 8 (12) ◽

pp. 1001

Author(s):

Wei Lin ◽

Cheng Su ◽

Youhong Tang

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Time Domain ◽

Vibration Analysis ◽

Random Vibration ◽

Present Approach ◽

Dynamic Responses ◽

Wave Loads ◽

Morison Equation ◽

Random Vibration Analysis

This paper is devoted to the random vibration analysis of jacket platforms under wave loads using the explicit time-domain approach. The Morison equation is first used to obtain the nonlinear random wave loads, which are discretized into random loading vectors at a series of time instants. The Newmark-β integration scheme is then employed to construct the explicit expressions for dynamic responses of jacket platforms in terms of the random vectors at different time instants. On this basis, Monte Carlo simulation can further be conducted at high efficiency, which not only provides the statistical moments of the random responses, but also gives the mean peak values of responses. Compared with the traditional power spectrum method, nonlinear wave loads can be readily taken into consideration in the present approach rather than using the equivalent linearized Morison equation. Compared with the traditional Monte Carlo simulation, the response statistics can be obtained through the direct use of the explicit expressions of dynamic responses rather than repeatedly solving the equation of motion. An engineering example is analyzed to illustrate the accuracy and efficiency of the present approach.

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Random Vibration Analysis of Coupled Three-Dimensional Maglev Vehicle-Bridge System

Advances in Civil Engineering ◽

10.1155/2019/4920659 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Wei Liu ◽

Wenhua Guo

Keyword(s):

State Space ◽

Governing Equation ◽

Vibration Analysis ◽

Random Vibration ◽

Three Dimensional ◽

Equation Of Motion ◽

Maglev Vehicle ◽

Random Vibration Analysis ◽

Space Equation ◽

Bridge System

This paper presents a framework for the linear random vibration analysis of the coupled three-dimensional (3D) maglev vehicle-bridge system. Except for assembling the equation of motion of vehicle only via the principle of virtual work, the fully computerized approach is further expanded to assemble the governing equation of fluctuating current via the equilibrium relation. A state-space equation couples the equation of motion of the vehicle and the governing equation of fluctuating current. The equation of motion of a real three-span space continuous girder bridge is established by using finite element methods. A separated iteration method based on the precise integration method and the Newmark method is introduced to solve the state-space equation for the maglev vehicle and the equation of motion for the bridge. Moreover, a new scheme to application of the pseudoexcitation method (PEM) in random vibration analysis is proposed to maximize the computational efficiency of the random vibration analysis of the maglev vehicle-bridge system. Finally, the numerical simulation demonstrates that the proposed framework can efficiently obtain the mean value, root mean square (RMS), standard deviation (SD), and power spectral density (PSD) of dynamic response for the coupled 3D maglev vehicle-bridge system.

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