Search

This paper focusses on the effects produced by the viscoelastic modelling of pavement on the dynamics of vehicle–pavement coupled system. The pavement is modelled as a two-layer finite length Euler–Bernoulli beam with uniform cross-section resting on a nonlinear Pasternak foundation. A harmonic roughness profile is considered for the pavement. The top layer of the pavement is modelled as a viscoelastic material representing the asphalt topping and the bottom layer is modelled as elastic material representing the base course. Burgers model is used to model the viscoelastic response of the top layer. Galerkin method and Runge–Kutta method are employed to discretise the differential equations arising from the dynamic equations of motion of the system. The vehicle is modelled as a spring-mass-damper system. The physical parameters of the system are compared for determining their influences on the coupled vibratory response. The effect of pavement roughness on the dynamic responses is also studied. The effects of acceleration of the vehicle and temperature on the response of the system are investigated. Additionally, the effect of coupling action on pavement displacements and vehicle body vertical displacement is examined. Numerical results suggest that the viscoelastic effects of asphalt pavement cannot be neglected in the dynamic analysis of vehicle–pavement coupled systems. [ABSTRACT FROM AUTHOR]

• Efficient technique to study the dynamics of vehicle-pavement system is presented. • Studied the effect of random road roughness on the coupled system responses. • Investigated the influence of two pavement models on the coupled system responses. • The method is competent when multiple vehicles move simultaneously on the pavement. This paper presents an iterative decoupled technique for the dynamic response of vehicle-pavement systems. The method involves the decoupling of the vehicle-pavement coupled system into two subsystems and solving them independently until the solution has converged using an iterative scheme. The technique uses a combination of the Galerkin method, finite difference method, and Newmark's method for discretizing the differential equation and computing the dynamic response. The proposed method is illustrated for two pavement models. The first model idealizes the pavement as a Timoshenko beam resting on a nonlinear foundation. The second model considers the pavement as a double-layer rectangular thin plate on a two-parameter foundation. The vehicle is simplified as a spring-mass-damper oscillator. The effect of the two pavement models on the dynamic response is investigated. Random roughness profiles for two different quality of roads is considered, and Monte Carlo simulation is used to compute the stochastic system responses. Additionally, the effect of coupling action on pavement displacements and vehicle body vertical displacement are examined. Numerical study on the proposed technique reveals that the method has a linear rate of convergence. The competence of the technique in computing the dynamic response of a pavement traversed by multiple vehicles is demonstrated. Numerical investigations prove that the decoupled technique is not only computationally efficient but also has the potential to tackle complicated problems in vehicle-pavement system dynamics. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a coupling technique for integrating the element-free Galerkin method (EFGM) with the fractal finite element method (FFEM) to analyze unbounded problems in the half-space. FFEM is adopted to model the far field of an unbounded domain and EFGM is used in the near field. In the transition region interface elements are employed. The shape functions of interface elements which comprise both the element-free Galerkin and the finite element shape functions, satisfy the consistency condition thus ensuring convergence of the proposed coupled EFGM–FFEM. The proposed method combines the best features of EFGM and FFEM, in the sense that no structured mesh or special enriched basis functions are necessary. The numerical results show that the proposed method performs extremely well converging rapidly to the analytical solution. Also a parametric study is carried out to examine the effects of the integration order, the similarity ratio, the weight function, the scaling parameter and the number of transformation terms, on the quality of the numerical solutions. [Copyright &y& Elsevier]

Abstract: This paper presents a stochastic meshfree method for solving boundary-value problems in damage mechanics under elasto-plastic conditions. Isotropic ductile damage evolution law is used to model the coupled elasto-plastic damage growth. Uncertainty associated with initial damage in materials is considered as random field. Moving least squares shape function method and Karhunen Loève expansion method are used for random field discretization. Statistical parameters of the response quantities are computed using perturbation method. The proposed method involves a new stochastic stress update procedure to solve the nonlinear equations in terms of discretized random variables arising from perturbation of equilibrium equations system. Numerical examples comprising of one and two dimensional problems are presented to illustrate the effectiveness of proposed method. [Copyright &y& Elsevier]

This paper presents a Galerkin-based meshless method for calculating stress-intensity factors (SIFs) for a stationary crack in two-dimensional functionally graded materials of arbitrary geometry. The method involves an element-free Galerkin method (EFGM), where the material properties are smooth functions of spatial coordinates and two newly developed interaction integrals for mixed-mode fracture analysis. These integrals can also be implemented in conjunction with other numerical methods, such as the finite element method (FEM). Five numerical examples including both mode-I and mixed-mode problems are presented to evaluate the accuracy of SIFs calculated by the proposed EFGM. Comparisons have been made between the SIFs predicted by EFGM and available reference solutions in the literature, generated either analytically or by FEM using various other fracture integrals or analyses. A good agreement is obtained between the results of the proposed meshless method and the reference solutions. [Copyright &y& Elsevier]