http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12139 Finite element analysis of the penetration of a solid object into a soil layer is probably one of the most sophisticated and challenging problems in numerical analysis. In this study the Arbitrary Lagrangian-Eulerian method is employed to study numerically the penetration of a free falling penetrometer into a layer of soil. It is shown that this method can simulate deep penetration of objects into layers of soil accurately. Good agreement has been found between the numerical predictions and experimental results. 2012-12-05T23:35:18.057Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12153 In many geotechnical problems it is vital to consider the geometrical non-linearity caused by large deformation in order to capture a more realistic model of the true behaviour. The solutions so obtained should then be more accurate and reliable, which should ultimately lead to cheaper and safer design. The Arbitrary Lagrangian-Eulerian (ALE) method originated from fluid mechanics, but has now been well established for solving large deformation problems in geomechanics. This paper provides an overview of the ALE method and its challenges in tackling problems involving non-linearities due to material behaviour, large deformation, changing boundary conditions and time-dependency, including material rate effects and inertia effects in dynamic loading applications. Important aspects of ALE implementation into a finite element framework will also be discussed. This method is then employed to solve some interesting and challenging geotechnical problems such as the dynamic bearing capacity of footings on soft soils, consolidation of a soil layer under a footing, and the modelling of dynamic penetration of objects into soil layers. 2012-11-30T03:58:37.465Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11990 The simulation of free falling objects penetrating seabed soil deposits is one of the most sophisticated and challenging problems encountered in numerical modelling when using the Finite Element Method. This paper describes a robust numerical method for dealing with such complex and difficult problems. The approach is based on the Arbitrary Lagrangian-Eulerian (ALE) method of analysis, whose main features and challenges are described briefly in the paper. Application of this method to the simulation of dynamic penetration of instruments into undrained layers of uniform soil is discussed in some detail and comparisons with experimental observations are made. 2012-11-09T06:34:24.010Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8069 This paper presents a nonlinear analysis of reinforced concrete structures. Various yield surfaces of concrete are reviewed in the beginning and then a recently proposed yield surface for concrete is introduced. The yield surface considers the behavior of concrete in a three-dimensional stress state. Based on the yield surface, a nonlinear finite element formulation is provided to facilitate a three-dimensional analysis of reinforced concrete structures. An eight-node brick element is used in the analysis. Several numerical examples are given to show the ability of the yield surface in solving nonlinear reinforced concrete problems. 2011-07-05T05:50:09.494Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7398 In this paper an arbitrary Lagrangian–Eulerian (ALE) method to solve dynamic problems involving large deformation is presented. This ALE method is based upon the operator-split technique in which the material displacements and mesh displacements are uncoupled. A brief history of the ALE method is first presented and then special issues such as time-stepping, mesh refinement, energy absorbing boundaries, dynamic equilibrium checks and remapping of state variables are explained. The ALE method and the updated-lagrangian (UL) method are then used to analyse some geotechnical problems to examine the significance of inertia effects, large deformation and contact mechanics. The results show the efficiency of the ALE method for solving dynamic geotechnical problems involving large deformation. 2011-03-16T05:10:24.411Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:6087 In this paper, an Arbitrary Lagrangian-Eulerian (ALE) method is addressed to solve dynamic problems involving large deformation. This ALE method is based upon the operator split technique in which the material displacements and mesh displacements are uncoupled. Special issues such as time-stepping, mesh refinement, dynamic equilibrium checks and remapping of state variables are briefly explained. The ALE method and the Updated-Lagrangian (UL) method are then used to analyse a rigid footing to examine the significance of inertia effects and large deformation on the predicted footing response. The results show the efficiency of the ALE method for solving dynamic geotechnical problems involving large deformations. 2010-05-13T01:00:01.081Z ]]>