School of Technology: Recent submissions

Now showing items 201-220 of 369

  • Simulating discontinuities in a gradient-enhanced continuum 

    Simone, A; Wells, Garth Nathan; Sluys, LJ (Proceedings of the International Conference on Structural Integrity and FractureProceedings of the International Conference on Structural Integrity and Fracture, 2002)
    A continuum-discrete model for failure in quasi-brittle materials is presented. The continuum is regularised through the introduction of gradient terms into the constitutive model. At the transition to discrete failure, ...

  • Analysis of delamination growth with discontinuous finite elements 

    Remmers, JJC; Wells, Garth Nathan; De Borst, R (Solids, Structures and Coupled Problems in EngineeringSolids, Structures and Coupled Problems in Engineering, 2001)
    In this contribution a new finite element is presented for the simulation of delamination growth in thin layered composite materials. The element is based on the solid-like shell element, a volume element that can be used ...

  • Discontinuous modelling of crack propagation in a gradient-enhanced continuum 

    Simone, A; Wells, Garth Nathan; Sluys, LJ (2002)
    A numerical model for the description of the combined continuous/discontinuous failure in a regularised strain-softening continuum is proposed. The continuum is regularised through the introduction of gradient terms into ...

  • A combined experimental-numerical study to tensile behaviour of limestone 

    De Proft, K; Wells, Garth Nathan; Sluys, LJ; De Wilde, WP (Proceedings of the 3rd International Conference on Emerging Technologies in Non Destructive TestingProceedings of the 3rd International Conference on Emerging Technologies in Non Destructive Testing, 2003-01-01)
    In this paper, a combined experimental-computational study of double-edge notched stone specimen subject to cyclic tensile loading is presented. In the experimental part, the load-deformation response and the local ...

  • A précis of some recent developments in computational failure mechanics 

    De Borst, R; Askes, H; Gutierrez, MA; Remmers, JJC; Wells, Garth Nathan (International Journal of Numerical Methods in Heat and Fluid FlowInternational Journal of Numerical Methods in Heat and Fluid Flow, 2004)
    A concise overview is given of various numerical methods that can be used to analyse localisation and failure in engineering materials. The importance of the cohesive-zone approach is emphasised and various ways of ...

  • A formulation of the autoregressive HMM for speech synthesis 

    Shannon, Matt; Byrne, William (Department of Engineering, University of Cambridge, 2009-08-31)
    We present a formulation of the autoregressive HMM for speech synthesis and compare it to the standard HMM synthesis framework and the trajectory HMM. We give details of how to do efficient parameter estimation and synthesis ...

  • Discontinuities in regularised media 

    Simone, A; Wells, Garth Nathan; Sluys, LJ (2003)
    Discontinuous interpolation of the problem fields in non-local and rate-dependent media is considered. The necessity of discontinuities in the analysis of failure processes and some of the requirements for the introduction ...

  • Discontinuous modelling of strain localisation and failure 

    Wells, G N (Delft University of Technology, 2001-06-12)
    The computational simulation of failure in solids poses many challenges. A proper understanding of how structures respond under loading, both before and past the peak load, is important for safe and economical constructions. ...

  • Make-buy decisions in the face of radical innovations. 

    Perrons, Robert Kirby (University of Cambridge, 2004-10-26)
    Some research in the area of make-buy decisions for new technologies suggests that it is a good idea for a company to pursue a fairly rigorous “make” policy in the early days of a potentially disruptive innovation. Other ...

  • A continuous/discontinuous Galerkin formulation for a strain gradient-dependent damage model: 2D results 

    Wells, Garth Nathan; Garikipati, K; Molari, L (Proceedings of the 6th World Congress on Computational Mechanics in Conjunction with theputational Mechanics 2nd Asian-Pacific Congress on Computational MechanicsProceedings of the 6th World Congress on Computational Mechanics in Conjunction with theputational Mechanics 2nd Asian-Pacific Congress on Computational Mechanics, 2004)
    The numerical solution of strain gradient-dependent continuum problems has been hindered by continuity demands on the basis functions. The presence of terms in constitutive models which involve gradients of the strain eld ...

  • A continuous/discontinuous Galerkin formulation for a strain gradient-dependent damage model 

    Wells, Garth Nathan; Garikipati, K; Molari, L (4th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS)4th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS), 2004)
    The numerical solution of strain gradient-dependent continuum problems has been hindered by continuity demands on the basis functions. The presence of terms in constitutive models that involve gradients of the strain field ...

  • Formulation of continuous/discontinuous Galerkin methods for strain gradient-dependent damage 

    Molari, L; Garikipati, K; Wells, Garth Nathan (Strength Fracture and ComplexityStrength Fracture and Complexity, 2006)
    Continuum damage models are widely used to represent the development of microscopic defects that coalesce into a macroscopic crack. The microscopic defects cause a progressive weakening or softening of the material (damage). ...

  • Automated modelling of viscoelastic flow using FEniCS 

    Molari, L; Wells, Garth Nathan (XVI Convegno Italiano di Meccanica ComputazionaleXVI Convegno Italiano di Meccanica Computazionale, 2006)
    Using high-level abstractions, it is possible to efficiently automate the development of finite element models. This has advantages in terms of rapid development, a dramatic reduction in programming errors and offers the ...

  • A study of discontinuous Galerkin methods for thin bending problems 

    Dung, NT; Wells, Garth Nathan (Computational Mechanics: Solids Structures and Coupled ProblemsComputational Mechanics: Solids Structures and Coupled Problems, 2006)
    Various continuous/discontinuous Galerkin formulations are examined for the analysis of thin plates. These methods rely on weak imposition of continuity of the normal slope across element boundaries. We draw here upon ...

  • A $C^0$ discontinuous Galerkin formulation for thin shells 

    Dung, N T; Wells, G N (2007)
    This paper presents a C 0 discontinuous Galerkin formulation for the simulation of thin shells. The method is based on Koiter’s shell model and allows finite element solutions to be obtained by using standard $C^0$ Lagrange ...

  • Long-term behaviour of twin tunnels in London clay 

    Laver, Richard George (University of CambridgeDepartment of EngineeringCorpus Christi College, 2011-03-15)
    The assessment of ageing tunnels requires a deeper understanding of the long-term behaviour of twin tunnels, whilst lack of permeability data limits the accuracy of long-term predictions. This thesis therefore investigates ...

  • Ultra-fast Imaging of Two-Phase Flow in Structured Monolith Reactors; Techniques and Data Analysis 

    Heras, Jonathan Jaime (University of CambridgeDepartment of Chemical Engineering, 2007-03)
    This thesis will address the use of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) techniques to probe the “monolith reactor”, which consists of a structured catalyst over which reactions may occur. ...

  • The dynamic cutting of metals 

    Smith, J D (University of CambridgeEngineering Laboratory, 1962)
    Prediction of regenerative machine tool chatter requires a knowledge of the cutting forces existing under vibration conditions. Previous direct experimental work has been very limited in its range and has given results ...

  • An interface element based on the partition of unity 

    Simone, A; Remmers, Joris J C; Wells, G N (Delft University of Technology, 2001)
    An alternative interface finite element is developed. By using the partition of unity property of finite element shape functions, discontinuous shape functions are added to the standard finite element basis. The interface ...

  • Bayesian methods in music modelling 

    Peeling, Paul (University of CambridgeDepartment of Engineering, 2011-03-15)
    This thesis presents several hierarchical generative Bayesian models of musical signals designed to improve the accuracy of existing multiple pitch detection systems and other musical signal processing applications whilst ...