scholarly journals A vehicle-track-soil dynamic interaction problem in sequential and parallel formulation

2010 ◽  
Vol 20 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Janusz Kogut ◽  
Henryk Ciurej
Keyword(s):  
Numerical Modeling ◽  
Dynamic Interaction ◽  
Computational Time ◽  
Model Formulation ◽  
Railway Traffic ◽  
Matlab Code ◽  
Discrete Step ◽  
Parallel Formulation ◽  
Soil Dynamic ◽  
Interaction Problem

A vehicle-track-soil dynamic interaction problem in sequential and parallel formulationSome problems regarding numerical modeling of predicted vibrations excited by railway traffic are discussed. Model formulation in the field of structural mechanics comprises a vehicle, a track (often in a tunnel) and soil. Time consuming computations are needed to update large matrices at every discrete step. At first, a sequential Matlab code is generated. Later on, the formulation is modified to use grid computing, thereby a significant reduction in computational time is expected.

scholarly journals Hydrodynamic Interactions in Multiple Body Array: A Simple and Fast Approach Coupling Boundary Element Method and Plane Wave Approximation

2013 ◽  
Author(s):  
Jitendra Singh ◽  
Aurélien Babarit
Keyword(s):  
Boundary Element Method ◽  
Plane Wave ◽  
Boundary Element ◽  
Hydrodynamic Interaction ◽  
Computational Time ◽  
Linear Potential ◽  
Wave Approximation ◽  
Interaction Problem ◽  
Plane Wave Approximation ◽  
Element Method

The hydrodynamic forces acting on an isolated body could be considerably different than those when it is considered in an array of multiple bodies, due to wave interactions among them. In this context, we present in this paper a numerical approach based on the linear potential flow theory to solve full hydrodynamic interaction problem in a multiple body array. In contrast to the previous approaches that considered all bodies in an array as a single unit, the present approach relies on solving for an isolated body. The interactions among the bodies are then taken into account via plane wave approximation in an iterative manner. The boundary value problem corresponding to a isolated body is solved by the Boundary Element Method (BEM). The approach is useful when the bodies are sufficiently distant from each other, at-least greater than five times the characteristic dimensions of the body. This is a valid assumption for wave energy converter devices array of point absorber type, which is our target application at a later stage. The main advantage of the proposed approach is that the computational time requirement is significantly less than the commonly used direct BEM. The time savings can be realized for even small arrays consisting of four bodies. Another advantage is that the computer memory requirements are also significantly smaller compared to the direct BEM, allowing us to consider large arrays. The numerical results for hydrodynamic interaction problem in two arrays consisting of 25 cylinders and same number of rectangular flaps are presented to validate the proposed approach.

On the Dynamic Behaviour of Offshore Foundation Footings in a Moving Ocean Bed

2006 ◽  
Author(s):  
Vincent O. S. Olunloyo ◽  
Charles A. Osheku
Keyword(s):  
Dynamic Behaviour ◽  
Integral Transform ◽  
Three Dimensional ◽  
Dynamic Interaction ◽  
External Excitation ◽  
Foundation Soil ◽  
Hydrodynamic Loading ◽  
Response Profiles ◽  
And Performance ◽  
Soil Dynamic

The reliability of partly submerged production storage platforms deployed for the exploitation of geo-resources in deep and ultra-deep offshore locations is strongly influenced by the dynamic stability and performance of their foundation footings under hydrodynamic loading and external excitation. This paper presents an integral transform approach for investigating the effects of the three-dimensional motion of the gripping ocean bed subsoil layer under pressurized external excitation. For this, the fluid-foundation-soil dynamic interaction boundary value problem is modeled as an elastic plate on an elastic foundation. In particular, closed form expressions for the dynamic response profiles and the natural frequency of vibration as modulated by the ocean bed poro-mechanics are analysed and presented.

Theoretical and Numerical Solutions of Maglev Train Induced Vibration

2013 ◽  
Vol 459 ◽  
pp. 271-277
Author(s):  
S.H. Ju ◽  
C.C. Leong ◽  
Y.S. Ho
Keyword(s):  
Control System ◽  
Numerical Scheme ◽  
Large Time ◽  
Numerical Solutions ◽  
Step Length ◽  
Dynamic Interaction ◽  
Maglev Train ◽  
Time Step ◽  
Large Time Step ◽  
Interaction Problem

This paper proposed an efficient method based on theoretical equations to solve the dynamic interaction problem between the Timoshenko beam and maglev vehicles. A systematic PI numerical scheme is developed for the control system of the maglev train. The major advantage is that only one simple equation required in the control calculation, although the original control system is fairly complicated. Numerical simulations indicate that a large time step length can be used in the proposed method to obtain stable and accurate results.

Numerical Analysis on Adjacent Highrise and Multistoried Buildings-Pile-Soil Dynamic Interaction

2012 ◽  
Vol 446-449 ◽  
pp. 2299-2304
Author(s):  
Pei Zhen Li ◽  
Peng Xu ◽  
Zhao Hui Pan ◽  
Xi Lin Lu
Keyword(s):  
Numerical Analysis ◽  
Dynamic Interaction ◽  
Soil Dynamic

Vertical Penetration of Offshore Pipelines: A Comparative Study Between Finite Element and Finite Volume Methods

2015 ◽  
Author(s):  
Sujan Dutta ◽  
Bipul Hawlader ◽  
Ryan Phillips
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Strain Rate ◽  
Soil Water ◽  
Finite Volume ◽  
Computational Time ◽  
Near Surface ◽  
Water Interaction ◽  
Ansys Cfx ◽  
Penetration Behaviour

Deepwater surface laid pipelines generally penetrate a fraction of their diameter into the seabed. The near surface penetration behaviour of steel catenary risers (SCRs) is equally important in offshore oil and gas developments. Theoretical, physical and numerical investigations have been performed to understand pipeline–soil interaction during vertical penetration. The large deformation finite element (LDFE) modeling is a recent and advanced tool among different numerical modeling techniques. The authors of this study simulated the penetration of pipeline using Abaqus CEL Finite Element (FE) software [1]. They also developed a numerical modeling technique based on finite volume approach using ANSYS CFX [2] and showed some of its advantages. However, in that study an ideal soil (i.e. no softening or strain rate effects on undrained shear strength) was used. Strain rate and softening have significant effects on penetration behaviour and therefore in this study a numerical technique has been developed to incorporate these effects in ANSYS CFX. Comparison of the results shows that ANSYS CFX can also model the penetration behaviour. Moreover, ANSYS CFX has some advantages including low computational time, modeling of suction and pipeline–soil–water interaction. A parametric study is also presented to provide more insights into the pipeline–soil–water interaction.

An Efficient Algorithm for Nonlinear Analysis of Vehicle/Track Interaction Problems

2016 ◽  
Vol 16 (08) ◽  
pp. 1550040 ◽  
Author(s):  
J. Sadeghi ◽  
A. Khajehdezfuly ◽  
M. Esmaeili ◽  
D. Poorveis
Keyword(s):  
Time Domain ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Computational Cost ◽  
Dynamic Interaction ◽  
Integration Scheme ◽  
Equilibrium Equations ◽  
Track System ◽  
Newton Raphson ◽  
Interaction Problem

In this paper, a new algorithm for solving the vehicle/track dynamic interaction problem is developed, aimed at reducing the computational cost. The algorithm called Advanced Solver Algorithm (ASA) uses the full Newton–Raphson incremental-iterative method in conjunction with the Newmark integration scheme to solve the equilibrium equations of the coupled vehicle/track system in time domain. Considering the track as a beam resting on a viscoelastic foundation and each vehicle as a wagon with ten degrees of freedom, the governing differential equations of motion of the vehicle/track system were derived. The wheel/rail contact was considered as a nonlinear Hertz spring and consequently the vehicle/track nonlinear dynamic interaction problem was solved. A comparison between the results of the ASA and those of the most advanced algorithm available was made to evaluate the efficiency of the ASA. It is confirmed that using the ASA can result in 40–70 % of reduction in computational cost.

scholarly journals Development of a Vehicle-Bridge-Soil Dynamic Interaction Model for Scour Damage Modelling

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
L. J. Prendergast ◽  
D. Hester ◽  
K. Gavin
Keyword(s):  
Model Development ◽  
Interaction Model ◽  
Dynamic Interaction ◽  
Sensor Technology ◽  
Bridge Foundations ◽  
Foundation Soil ◽  
Soil Response ◽  
Integral Bridge ◽  
Vehicle Loading ◽  
Soil Dynamic

Damage detection in bridges using vibration-based methods is an area of growing research interest. Improved assessment methodologies combined with state-of-the-art sensor technology are rapidly making these approaches applicable for real-world structures. Applying these techniques to the detection and monitoring of scour around bridge foundations has remained challenging; however this area has gained attraction in recent years. Several authors have investigated a range of methods but there is still significant work required to achieve a rounded and widely applicable methodology to detect and monitor scour. This paper presents a novel Vehicle-Bridge-Soil Dynamic Interaction (VBSDI) model which can be used to simulate the effect of scour on an integral bridge. The model outputs dynamic signals which can be analysed to determine modal parameters and the variation of these parameters with respect to scour can be examined. The key novelty of this model is that it is the first numerical model for simulating scour that combines a realistic vehicle loading model with a robust foundation soil response model. This paper provides a description of the model development and explains the mathematical theory underlying the model. Finally a case study application of the model using typical bridge, soil, and vehicle properties is provided.

Numerical modeling of vibrations induced by railway traffic in tunnels: From the source to the nearby buildings

2014 ◽  
Vol 61-62 ◽  
pp. 269-285 ◽  
Author(s):  
Patrícia Lopes ◽  
P. Alves Costa ◽  
M. Ferraz ◽  
R. Calçada ◽  
A. Silva Cardoso
Keyword(s):  
Numerical Modeling ◽  
Railway Traffic
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