Multiscale Extended Finite Element Method for the Simulation of Fractured Geological Formations

In the prevailing context of the 21st century, characterized by a predominant reliance on oil and gas, or in the promising future where green energy shapes a human society committed to net-zero emissions, the role of underground fractured formations in energy production and storage remains pivotal and irreplaceable. Geological faults typically...

On the fracture behavior of cortical bone microstructure: The effects of morphology and material characteristics of bone structural components

Bone encompasses a complex arrangement of materials at different length scales, which endows it with a range of mechanical, chemical, and biological capabilities. Changes in the microstructure and characteristics of the material, as well as the accumulation of microcracks, affect the bone fracture properties. In this study, two-dimensional...

A numerical framework for simulating progressive failure in composite laminates under high-cycle fatigue loading

In this work, a recently proposed high-cycle fatigue cohesive zone model, which covers crack initiation and propagation with limited input parameters, is embedded in a robust and efficient numerical framework for simulating progressive failure in composite laminates under fatigue loading. The fatigue cohesive zone model is enhanced with an...

Adaptive multiscale extended finite element method (MS-XFEM) for the simulation of multiple fractures propagation in geological formations

In fractured geological formations, as a result of the in-situ stress changes, fractures can propagate or slide. This phenomenon can be efficiently modeled by the extended finite element method (XFEM) when there are only a few fractures present. However, geological reservoirs contain many fractures which can also cross and are densely...

Mixed-mode fatigue crack propagation simulation by means of G_eq and walker models of the structural steel S355

In this paper, a numerical simulation method of mixed-mode fatigue crack propagation was explored using the extended finite element method (XFEM) and the Virtual Crack Closure Technique (VCCT). Both 2D and 3D numerical models were selected to simulate the fatigue crack propagation of steel specimens. Two coefficients were proposed to...

Strengthening effects evaluation on fatigue damage of rib to deck joint in orthotropic steel deck

Strengthening fatigue damage of orthotropic steel decks (OSDs) needs to comprehensively consider the strengthening effect and the dead weight introduced during the strengthening process, especially for OSDs in super large-span bridges or old renovated bridges, where the dead weight cannot be significantly increased during repair and...

A Numerical Investigation of an Abnormal Phenomenon of Stress Intensity Factor (SIF) in a Cracked T-Butt Joint Accounting for Welding Effect

Industry design standards such as BS 7910 deployed some empirical formulas for the prediction of stress intensity factor (SIF) based on simulation results from traditional finite element method (FEM). However, such FEM simulation occasionally failed to convince people due to the large discrepancies compared with engineering practice. As a...

Effects of residual stresses on fatigue crack propagation of an orthotropic steel bridge deck

Orthotropic steel decks (OSD's) are susceptible to fatigue failure due to cyclic loading. Often fatigue cracks are found in the joint between the deck plate and the trough. Due to the welding process, residual stresses are present in and around the joint. In this paper, the effect of residual stresses on the fatigue crack propagation rate has...

Numerical simulation on reflective cracking behavior of asphalt pavement

Cracks are one of the main problems that plague road workers. A correct understanding of the internal crack propagation mechanism of asphalt pavement will help road workers evaluate the road’s working status more comprehensively and make more reasonable decisions in design, construction, and maintenance work. This paper established a three...

Three-dimensional fatigue crack propagation simulation using extended finite element methods for steel grades S355 and S690 considering mean stress effects

The assessment of fatigue crack propagation of steel structures is essential and important especially to improve the application of high strength steel in construction. The load ratio R, reflecting mean stress effects, will be changed with crack extension in the steel structures with complicated geometry. In this paper, the Walker equation is...

Multiscale extended finite element method for deformable fractured porous media

Deformable fractured porous media appear in many geoscience applications. While the extended finite element method (XFEM) has been successfully developed within the computational mechanics community for accurate modeling of deformation, its application in geoscientific applications is not straightforward. This is mainly due to the fact that...

Fatigue crack initiation prediction using phantom nodes-based extended finite element method for S355 and S690 steel grades

The assessment of fatigue crack initiation behavior of steel structures is essential and important especially to improve the application of high strength steel in construction. For a complete understanding of fatigue endurance, it is necessary to combine the phenomenological damage model with finite element numerical approach. In this paper,...

A Numerical Study on the Effect of Anisotropy on Hydraulic Fractures

In this paper, we present a two-dimensional numerical model for modelling of hydraulic fracturing in anisotropic media. The numerical model is based on extended finite element method. The saturated porous medium is modelled using Biot’s theory of poroelasticity. An enhanced local pressure model is used for modelling the pressure within the...

Progressive damage modelling of FRPs using a blended stress-strain and fracture mechanics approach in FEM

Despite great strides made in understanding and modelling Fiber-Reinforced Polymers (FRPs), their full potential is held back by the inability to accurately predict failure. Contrary to past attempts focused on isolated application of stress-strain and fracture mechanics based failure theories, this research builds upon the existing framework by...

Levelset based fluid-structure interaction modeling with the eXtended Finite Element Method

This study focuses on solving steady state fluid-structure interaction (FSI) problems subjected to incompressible flow at low Reynolds numbers and linear elastic structural behavior. The fluid-structure interface geometry is described with a levelset method (LSM). The governing equations are discretized in space with the eXtended Finite Element...

Bridging Scales with a Generalized Finite Element Method

The generalized FEM (GFEM) has been successfully applied to the simulation of dynamic propagating fractures, polycrystalline and fiber-reinforced microstructures, porous materials, etc. A-priori knowledge about the solution of these problems are used in the definition of their GFEM approximation spaces. This leads to more accurate and robust...

Automated Modelling of Evolving Discontinuities

The automated approximation of solutions to differential equations which involve discontinuities across evolving surfaces is addressed. Finite element technology has developed to the point where it is now possible to model evolving discontinuities independently of the underlying mesh, which is particularly useful in simulating failure of solids....

An eXtended Finite Element Method based approach for large deformation fluid-structure interaction

This paper illustrates aspects of an ongoing effort to develop a fixed grid fluid-structure interaction scheme that can be applied to the interaction of most general structures with incompressible flow. After presenting a list of requirements for future fixed grid methods, an eXtended Finite Element Method (XFEM) based fixed grid method is...