Refined nonlinear fractional derivative model of vehicle-track coupling dynamics

The coupled vehicle-track system (CVTS) dynamics have been extensively investigated for decades. However, the calculation accuracy of prevailing vehicle-track coupling models needs to be improved in the high frequency range due to the inappropriate model simplification and neglect of material nonlinearity. In this study, we propose a refined...

Enriched finite element methods for fracture-based analysis and design

Cracks, which could nucleate and propagate in engineering structures, could have an adverse effect on mechanical performance and even lead to catastrophic failure. Thus, it is critical to investigate structural behavior under fracture, which requires an appropriate modeling methodology for fracture analysis. Furthermore, designing structures...

On tailoring fracture resistance of brittle structures: A level set interface-enriched topology optimization approach

We propose a fully immersed topology optimization procedure to design structures with tailored fracture resistance under linear elastic fracture mechanics assumptions for brittle materials. We use a level set function discretized by radial basis functions to represent the topology and the Interface-enriched Generalized Finite Element Method ...

An object-oriented geometric engine design for discontinuities in unfitted/immersed/enriched finite element methods

In this work, an object-oriented geometric engine is proposed to solve problems with discontinuities, for instance, material interfaces and cracks, by means of unfitted, immersed, or enriched finite element methods (FEMs). Both explicit and implicit representations, such as geometric entities and level sets, are introduced to describe...

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...

An interface-enriched generalized finite element method for level set-based topology optimization

During design optimization, a smooth description of the geometry is important, especially for problems that are sensitive to the way interfaces are resolved, e.g., wave propagation or fluid-structure interaction. A level set description of the boundary, when combined with an enriched finite element formulation, offers a smoother description...

Construction and application of algebraic dual polynomial representations for finite element methods on quadrilateral and hexahedral meshes

Given a sequence of finite element spaces which form a de Rham sequence, we will construct dual representations of these spaces with associated differential operators which connect these spaces such that they also form a de Rham sequence. The dual representations also need to satisfy the de Rham sequence on the domain boundary. The matrix...

A stable discontinuity-enriched finite element method for 3-D problems containing weak and strong discontinuities

A new enriched finite element technique, named the Discontinuity-Enriched Finite Element Method (DE-FEM), was introduced recently for solving problems with both weak and strong discontinuities in 2-D. In this mesh-independent procedure, enriched degrees of freedom are added to new nodes collocated at the intersections between discontinuities...

Coupled hygro-mechanical finite element method on determination of the interlaminar shear modulus of glass fiber-reinforced polymer laminates in bridge decks under hygrothermal aging effects

To investigate the mechanical degradation of the shear properties of glass fiber-reinforced polymer (GFRP) laminates in bridge decks under hygrothermal aging effects, short-beam shear tests were performed following the ASTM test standard (ASTM D790-10A). Based on the coupled hygro-mechanical finite element (FE) analysis method, an inverse...

Multiscale Lattice Boltzmann-Finite Element Modelling of Transport Properties in Cement-based Materials

Cement-based materials are the most widely used man-made materials in the world. The durability of cement-based materials has been a major concern due to the premature failure and serviceability issues of many reinforced concrete structures. Durability of cement-based materials is to a large content dependent on their resistance to the ingress...