The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform

Carlos G Davila - One of the best experts on this subject based on the ideXlab platform.

  • cohesive modeling of transverse cracking in laminates under in plane loading with a single layer of elements per Ply
    International Journal of Solids and Structures, 2013
    Co-Authors: Frans P Van Der Meer, Carlos G Davila
    Abstract:

    Abstract This study aims to bridge the gap between classical understanding of transverse cracking in cross-Ply laminates and recent computational methods for the modeling of progressive laminate failure. Specifically, the study investigates under what conditions a finite element model with cohesive X-FEM cracks can reproduce the in situ effect for the Ply Strength. It is shown that it is possible to do so with a single element across the thickness of the Ply, provided that the interface stiffness is properly selected. The optimal value for this interface stiffness is derived with an analytical shear lag model. It is also shown that, when the appropriate statistical variation of properties has been applied, models with a single element through the thickness of a Ply can predict the density of transverse matrix cracks.

  • cohesive modeling of transverse cracking in laminates with a single layer of elements per Ply
    2013
    Co-Authors: Frans P Vandermeer, Carlos G Davila
    Abstract:

    This study aims to bridge the gap between classical understanding of transverse cracking in cross-Ply laminates and recent computational methods for the modeling of progressive laminate failure. Specifically, the study investigates under what conditions a finite element model with cohesive X-FEM cracks can reproduce the in situ effect for the Ply Strength. It is shown that it is possible to do so with a single element across the thickness of the Ply, provided that the interface stiffness is properly selected. The optimal value for this interface stiffness is derived with an analytical shear lag model. It is also shown that, when the appropriate statistical variation of properties has been applied, models with a single element through the thickness of a Ply can predict the density of transverse matrix cracks

  • modeling transverse cracking in laminates with a single layer of elements per Ply
    ECCM 15: 15th European Conference on Composite Materials Venice Italy 24-28 June 2012, 2012
    Co-Authors: F P Van Der Meer, Carlos G Davila
    Abstract:

    This study aims to bridge the gap between classical understanding of transverse cracking in [0/90]s laminates and recent computational methods for the modeling of progressive laminate failure. Specifically, the study investigates under which conditions a three-dimensional model with cohesive cracks can reproduce the in situ effect for the Ply Strength. Subsequently, it is shown that it is possible to reproduce matrix cracking with a single element across the thickness of the Ply, provided that the interface stiffness is properly selected. By using an interface stiffness that is inversely proportional to the Ply thickness, a shear lag deformation is achieved that is equivalent to the opening deformation of a transverse matrix crack.

  • analytical modelling of transverse matrix cracking of θ 90n s composite laminates under multiaxial loading
    Mechanics of Advanced Materials and Structures, 2010
    Co-Authors: Joan A. Mayugo, P P Camanho, P Maimi, Carlos G Davila
    Abstract:

    An analytical model based on the analysis of a cracked unit cell of a composite laminate subjected to multiaxial loads is proposed to predict the onset and accumulation of transverse matrix cracks in the 90n plies of uniformly stressed {±θ/90n} s laminates. The model predicts the effect of matrix cracks on the stiffness of the laminate, as well as the ultimate failure of the laminate, and it accounts for the effect of the Ply thickness on the Ply Strength. Several examples describing the predictions of laminate response, from damage onset up to final failure under both uniaxial and multiaxial loads, are presented.

  • prediction of in situ Strengths and matrix cracking in composites under transverse tension and in plane shear
    Composites Part A-applied Science and Manufacturing, 2006
    Co-Authors: P P Camanho, Carlos G Davila, S T Pinho, Leonardo Iannucci, P Robinson
    Abstract:

    A criterion for matrix failure of laminated composite plies in transverse tension and in-plane shear is developed by examining the mechanics of transverse matrix crack growth. Matrix cracks are assumed to initiate from manufacturing defects and can propagate within planes parallel to the fiber direction and normal to the Ply mid-plane. Fracture mechanics models of cracks in unidirectional laminates, embedded plies and outer plies are used to determine the onset and direction of propagation of crack growth. The models for each Ply configuration relate Ply thickness and Ply toughness to the corresponding in situ Ply Strength. Calculated results for several materials are shown to correlate well with experimental results.

Carlos Gonzalez - One of the best experts on this subject based on the ideXlab platform.

  • transverse cracking of cross Ply laminates a computational micromechanics perspective
    Composites Science and Technology, 2015
    Co-Authors: Miguel Gonzalez Herraez, Ferran Naya, C. S. Lópes, Carlos Gonzalez, Diego Mora
    Abstract:

    Abstract Transverse cracking in cross-Ply carbon/epoxy and glass/epoxy laminates in tension is analyzed by means of computational micromechanics. Longitudinal plies were modeled as homogenized, anisotropic elastic solids while the actual fiber distribution was included in the transverse plies. The mechanical response was obtained by the finite element analysis of a long representative volume element of the laminate. Damage in the transverse plies was triggered by interface decohesion and matrix cracking. The simulation strategy was applied to study the influence of Ply thickness on the critical stress for the cracking of the transverse plies and on the evolution of crack density in 0 2 / 90 n / 2 s laminates, with n = 1, 2, 4 and 8. It was found that the transverse Ply Strength corresponding to the initiation and propagation of a through-thickness crack was independent of the Ply thickness and that the transverse Strength of carbon/epoxy laminates was 35% higher than that of the glass fiber counterparts. In addition, the mechanisms of crack initiation and propagation through the thickness as well as of multiple matrix cracking were ascertained and the stiffness reduction in the 90° Ply as a function of crack density was computed as a function of the Ply thickness.

P Robinson - One of the best experts on this subject based on the ideXlab platform.

  • prediction of in situ Strengths and matrix cracking in composites under transverse tension and in plane shear
    Composites Part A-applied Science and Manufacturing, 2006
    Co-Authors: P P Camanho, Carlos G Davila, S T Pinho, Leonardo Iannucci, P Robinson
    Abstract:

    A criterion for matrix failure of laminated composite plies in transverse tension and in-plane shear is developed by examining the mechanics of transverse matrix crack growth. Matrix cracks are assumed to initiate from manufacturing defects and can propagate within planes parallel to the fiber direction and normal to the Ply mid-plane. Fracture mechanics models of cracks in unidirectional laminates, embedded plies and outer plies are used to determine the onset and direction of propagation of crack growth. The models for each Ply configuration relate Ply thickness and Ply toughness to the corresponding in situ Ply Strength. Calculated results for several materials are shown to correlate well with experimental results.

Karl Schulte - One of the best experts on this subject based on the ideXlab platform.

  • estimation of the 90 Ply Strength distribution and shear lag parameter from multiple transverse cracking in graphite epoxy cross Ply laminates
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 1992
    Co-Authors: Shojiro Ochiai, Kozo Osamura, Piet W M Peters, Karl Schulte
    Abstract:

    Abstract A method to estimate the Weibull parameters for the Strength distribution of a transverse Ply and the shear lag parameter (the ratio of the shear modulus G to the thickness b of the shear transfer region) in cross-Ply 0 2 /90 4 /0 2 , 0 2 /90 6 /0 2 and 0 2 /90 12 /0 2 graphite-epoxy laminates from multiple transverse cracking was proposed and applied to experimental results. The estimated values of the Weibull parameters were essentially the same as those estimated by the Peters method. The value of the shear lag parameter G / b was found to be 50–100 MPa μm −1 for 0 2 /90 4 /0 2 and 0 2 /90 6 /0 2 laminates. On the contrary, the experimental results on the multiple cracking of the 90° Ply in a 0 2 /90 12 /0 2 laminate at high applied stresses could not be described by the value of G / b = 50–100 MPa μ m −1 , possibly owing to the occurrence of plastic deformation and/or shear failure in the 0°–90° interface.

P P Camanho - One of the best experts on this subject based on the ideXlab platform.

  • analytical modelling of transverse matrix cracking of θ 90n s composite laminates under multiaxial loading
    Mechanics of Advanced Materials and Structures, 2010
    Co-Authors: Joan A. Mayugo, P P Camanho, P Maimi, Carlos G Davila
    Abstract:

    An analytical model based on the analysis of a cracked unit cell of a composite laminate subjected to multiaxial loads is proposed to predict the onset and accumulation of transverse matrix cracks in the 90n plies of uniformly stressed {±θ/90n} s laminates. The model predicts the effect of matrix cracks on the stiffness of the laminate, as well as the ultimate failure of the laminate, and it accounts for the effect of the Ply thickness on the Ply Strength. Several examples describing the predictions of laminate response, from damage onset up to final failure under both uniaxial and multiaxial loads, are presented.

  • prediction of in situ Strengths and matrix cracking in composites under transverse tension and in plane shear
    Composites Part A-applied Science and Manufacturing, 2006
    Co-Authors: P P Camanho, Carlos G Davila, S T Pinho, Leonardo Iannucci, P Robinson
    Abstract:

    A criterion for matrix failure of laminated composite plies in transverse tension and in-plane shear is developed by examining the mechanics of transverse matrix crack growth. Matrix cracks are assumed to initiate from manufacturing defects and can propagate within planes parallel to the fiber direction and normal to the Ply mid-plane. Fracture mechanics models of cracks in unidirectional laminates, embedded plies and outer plies are used to determine the onset and direction of propagation of crack growth. The models for each Ply configuration relate Ply thickness and Ply toughness to the corresponding in situ Ply Strength. Calculated results for several materials are shown to correlate well with experimental results.