The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform

Ronald Guillen - One of the best experts on this subject based on the ideXlab platform.

  • Analytical modeling of transient hygro-Elastic Stress Concentration – Application to embedded optical fiber in a non-uniform transient strain field
    Composites Science and Technology, 2020
    Co-Authors: Frederic Jacquemin, Sylvain Freour, Ronald Guillen
    Abstract:

    International audienceThe aim of this work is to propose an analytical model for transient hygro-Elastic Stresses in transversely isotropic multi-layered cylinders. This approach allows one to calculate the time and space dependent hygro-Elastic Stresses in fiber-reinforced composite submitted to hygroscopic fields by applying the classical continuum mechanics formalism. Application of the proposed model to the case of an embedded optical fiber shows interesting results, concerning the Stress field perturbation occurring in the composite in the vicinity of the intrusive optical fiber. The model proposed in this study provides a detailed Stress analysis of the inclusion which is required to correctly interpret the data collected through the optical fiber and deduce Stresses experienced by the host material

  • analytical modeling of transient hygro Elastic Stress Concentration application to embedded optical fiber in a non uniform transient strain field
    Composites Science and Technology, 2006
    Co-Authors: Frederic Jacquemin, Sylvain Freour, Ronald Guillen
    Abstract:

    The aim of this work is to propose an analytical model for transient hygro-Elastic Stresses in transversely isotropic multi-layered cylinders. This approach allows one to calculate the time and space dependent hygro-Elastic Stresses in fiber-reinforced composite submitted to hygroscopic fields by applying the classical continuum mechanics formalism. Application of the proposed model to the case of an embedded optical fiber shows interesting results, concerning the Stress field perturbation occurring in the composite in the vicinity of the intrusive optical fiber. The model proposed in this study provides a detailed Stress analysis of the inclusion which is required to correctly interpret the data collected through the optical fiber and deduce Stresses experienced by the host material.

  • Analytical modeling of transient hygro-Elastic Stress Concentration – Application to embedded optical fiber in a non-uniform transient strain field
    Composites Science and Technology, 2006
    Co-Authors: Frederic Jacquemin, Sylvain Freour, Ronald Guillen
    Abstract:

    The aim of this work is to propose an analytical model for transient hygro-Elastic Stresses in transversely isotropic multi-layered cylinders. This approach allows one to calculate the time and space dependent hygro-Elastic Stresses in fiber-reinforced composite submitted to hygroscopic fields by applying the classical continuum mechanics formalism. Application of the proposed model to the case of an embedded optical fiber shows interesting results, concerning the Stress field perturbation occurring in the composite in the vicinity of the intrusive optical fiber. The model proposed in this study provides a detailed Stress analysis of the inclusion which is required to correctly interpret the data collected through the optical fiber and deduce Stresses experienced by the host material.

David B Lanning - One of the best experts on this subject based on the ideXlab platform.

  • constant life diagram modified for notch plasticity
    International Journal of Fatigue, 2007
    Co-Authors: David B Lanning, Theodore Nicholas
    Abstract:

    Abstract A modified constant-life Haigh diagram has been formulated to account for plasticity occurring at Stress Concentrations under cyclic loading at sufficiently high Stress ratios. The notch plasticity is assumed to occur within a range of Elastic Stress Concentration factors, kt, and cycles to failure, Nf, such that plastic straining occurs only during the first cycle of constant-amplitude cycling and straining remains Elastic thereafter. This condition is expected to occur in high cycle fatigue at Stress Concentrations of moderate kt loaded at high Stress ratio. The validity of the model is assessed by means of fatigue data from Ti–6Al–4V notched specimens having a range of kt. The model, purposely kept simple for ease of use as a design tool, is found to capture trends in the fatigue data not predicted using traditional straight-line models on a mean Stress versus alternating Stress constant-life plot.

  • on the use of critical distance theories for the prediction of the high cycle fatigue limit Stress in notched ti 6al 4v
    International Journal of Fatigue, 2005
    Co-Authors: David B Lanning, Theodore Nicholas, George K. Haritos
    Abstract:

    Abstract Methods are investigated for predicting the high cycle fatigue (HCF) lives of notched cylindrical Ti–6Al–4V specimens using critical distance concepts that employ the Stress distribution in the vicinity of the notch. Cylindrical fatigue specimens had circumferential V-notches with a range of Elastic Stress Concentration factors ( k t =1.97–4.07). Notched and unnotched specimens were cycled to failure using a step-loading technique to generate points on a Haigh (Goodman) diagram for a constant fatigue life of 10 6 cycles. Finite element solutions were generated to provide Stress distributions for the notched gage sections. The Stress distributions were used in the search for a critical distance over which the quantities of mean Stress, Stress range, or Elastic strain energy may contribute to the fatigue process and can be correlated to similar quantities from smooth, unnotched specimens. If the decrease in the local Stress ratio at the notch root for high applied Stress ratio is accounted for in the analysis, trends independent of applied Stress ratio were found in the calculated critical distances. Predictions based upon the results gave accuracy to within 12% of the experimental fatigue limit Stresses and illustrate the method has promise for use in fatigue design of Ti–6Al–4V components.

  • Influence of Stress state on high cycle fatigue of notched Ti-6Al-4V specimens
    International Journal of Fatigue, 1999
    Co-Authors: David B Lanning, G. K. Haritos, Theodore Nicholas
    Abstract:

    Abstract The high cycle fatigue (HCF) notch size effect is investigated for Ti-6Al-4V flat dogbone specimens with two notch sizes, each having an Elastic Stress Concentration factor of Kt=2.72. Points were generated on a constant life Haigh diagram using a step-loading technique. The notch size effect is compared with previous results obtained from circumferentially notched cylindrical specimens in terms of the biaxial state of Stress at the notch root and von Mises effective Stress. Within the range of dimensions tested, there is limited dependence of the fatigue limit upon the notch root radius. Stresses at the notch root and the fatigue notch factor are examined as a function of uniaxial Stress, effective Stress, notch plasticity, and notch root radius.

  • Notch size effects in HCF behavior of Ti–6Al–4V☆
    International Journal of Fatigue, 1999
    Co-Authors: George K. Haritos, Theodore Nicholas, David B Lanning
    Abstract:

    Abstract The high cycle fatigue (HCF) behavior of Ti–6Al–4V is investigated for cylindrical specimens having three sizes of geometrically similar circumferential V-notches, each with an Elastic Stress Concentration factor, K t , of approximately 2.78. A step loading technique for obtaining a point on a constant life (10 6 cycles) Haigh diagram from a single test specimen was implemented. Tests were performed at Stress ratios of R =0.1, 0.5, and 0.8 for specimens machined from two different product forms of Ti–6Al–4V, bar and plate forgings. Results indicate that while there is a definite notch size effect in the Ti–6Al–4V bar within the range of notch sizes tested, little or no such effect exists in the plate.

Theodore Nicholas - One of the best experts on this subject based on the ideXlab platform.

  • constant life diagram modified for notch plasticity
    International Journal of Fatigue, 2007
    Co-Authors: David B Lanning, Theodore Nicholas
    Abstract:

    Abstract A modified constant-life Haigh diagram has been formulated to account for plasticity occurring at Stress Concentrations under cyclic loading at sufficiently high Stress ratios. The notch plasticity is assumed to occur within a range of Elastic Stress Concentration factors, kt, and cycles to failure, Nf, such that plastic straining occurs only during the first cycle of constant-amplitude cycling and straining remains Elastic thereafter. This condition is expected to occur in high cycle fatigue at Stress Concentrations of moderate kt loaded at high Stress ratio. The validity of the model is assessed by means of fatigue data from Ti–6Al–4V notched specimens having a range of kt. The model, purposely kept simple for ease of use as a design tool, is found to capture trends in the fatigue data not predicted using traditional straight-line models on a mean Stress versus alternating Stress constant-life plot.

  • on the use of critical distance theories for the prediction of the high cycle fatigue limit Stress in notched ti 6al 4v
    International Journal of Fatigue, 2005
    Co-Authors: David B Lanning, Theodore Nicholas, George K. Haritos
    Abstract:

    Abstract Methods are investigated for predicting the high cycle fatigue (HCF) lives of notched cylindrical Ti–6Al–4V specimens using critical distance concepts that employ the Stress distribution in the vicinity of the notch. Cylindrical fatigue specimens had circumferential V-notches with a range of Elastic Stress Concentration factors ( k t =1.97–4.07). Notched and unnotched specimens were cycled to failure using a step-loading technique to generate points on a Haigh (Goodman) diagram for a constant fatigue life of 10 6 cycles. Finite element solutions were generated to provide Stress distributions for the notched gage sections. The Stress distributions were used in the search for a critical distance over which the quantities of mean Stress, Stress range, or Elastic strain energy may contribute to the fatigue process and can be correlated to similar quantities from smooth, unnotched specimens. If the decrease in the local Stress ratio at the notch root for high applied Stress ratio is accounted for in the analysis, trends independent of applied Stress ratio were found in the calculated critical distances. Predictions based upon the results gave accuracy to within 12% of the experimental fatigue limit Stresses and illustrate the method has promise for use in fatigue design of Ti–6Al–4V components.

  • Influence of Stress state on high cycle fatigue of notched Ti-6Al-4V specimens
    International Journal of Fatigue, 1999
    Co-Authors: David B Lanning, G. K. Haritos, Theodore Nicholas
    Abstract:

    Abstract The high cycle fatigue (HCF) notch size effect is investigated for Ti-6Al-4V flat dogbone specimens with two notch sizes, each having an Elastic Stress Concentration factor of Kt=2.72. Points were generated on a constant life Haigh diagram using a step-loading technique. The notch size effect is compared with previous results obtained from circumferentially notched cylindrical specimens in terms of the biaxial state of Stress at the notch root and von Mises effective Stress. Within the range of dimensions tested, there is limited dependence of the fatigue limit upon the notch root radius. Stresses at the notch root and the fatigue notch factor are examined as a function of uniaxial Stress, effective Stress, notch plasticity, and notch root radius.

  • Notch size effects in HCF behavior of Ti–6Al–4V☆
    International Journal of Fatigue, 1999
    Co-Authors: George K. Haritos, Theodore Nicholas, David B Lanning
    Abstract:

    Abstract The high cycle fatigue (HCF) behavior of Ti–6Al–4V is investigated for cylindrical specimens having three sizes of geometrically similar circumferential V-notches, each with an Elastic Stress Concentration factor, K t , of approximately 2.78. A step loading technique for obtaining a point on a constant life (10 6 cycles) Haigh diagram from a single test specimen was implemented. Tests were performed at Stress ratios of R =0.1, 0.5, and 0.8 for specimens machined from two different product forms of Ti–6Al–4V, bar and plate forgings. Results indicate that while there is a definite notch size effect in the Ti–6Al–4V bar within the range of notch sizes tested, little or no such effect exists in the plate.

Frederic Jacquemin - One of the best experts on this subject based on the ideXlab platform.

  • Analytical modeling of transient hygro-Elastic Stress Concentration – Application to embedded optical fiber in a non-uniform transient strain field
    Composites Science and Technology, 2020
    Co-Authors: Frederic Jacquemin, Sylvain Freour, Ronald Guillen
    Abstract:

    International audienceThe aim of this work is to propose an analytical model for transient hygro-Elastic Stresses in transversely isotropic multi-layered cylinders. This approach allows one to calculate the time and space dependent hygro-Elastic Stresses in fiber-reinforced composite submitted to hygroscopic fields by applying the classical continuum mechanics formalism. Application of the proposed model to the case of an embedded optical fiber shows interesting results, concerning the Stress field perturbation occurring in the composite in the vicinity of the intrusive optical fiber. The model proposed in this study provides a detailed Stress analysis of the inclusion which is required to correctly interpret the data collected through the optical fiber and deduce Stresses experienced by the host material

  • analytical modeling of transient hygro Elastic Stress Concentration application to embedded optical fiber in a non uniform transient strain field
    Composites Science and Technology, 2006
    Co-Authors: Frederic Jacquemin, Sylvain Freour, Ronald Guillen
    Abstract:

    The aim of this work is to propose an analytical model for transient hygro-Elastic Stresses in transversely isotropic multi-layered cylinders. This approach allows one to calculate the time and space dependent hygro-Elastic Stresses in fiber-reinforced composite submitted to hygroscopic fields by applying the classical continuum mechanics formalism. Application of the proposed model to the case of an embedded optical fiber shows interesting results, concerning the Stress field perturbation occurring in the composite in the vicinity of the intrusive optical fiber. The model proposed in this study provides a detailed Stress analysis of the inclusion which is required to correctly interpret the data collected through the optical fiber and deduce Stresses experienced by the host material.

  • Analytical modeling of transient hygro-Elastic Stress Concentration – Application to embedded optical fiber in a non-uniform transient strain field
    Composites Science and Technology, 2006
    Co-Authors: Frederic Jacquemin, Sylvain Freour, Ronald Guillen
    Abstract:

    The aim of this work is to propose an analytical model for transient hygro-Elastic Stresses in transversely isotropic multi-layered cylinders. This approach allows one to calculate the time and space dependent hygro-Elastic Stresses in fiber-reinforced composite submitted to hygroscopic fields by applying the classical continuum mechanics formalism. Application of the proposed model to the case of an embedded optical fiber shows interesting results, concerning the Stress field perturbation occurring in the composite in the vicinity of the intrusive optical fiber. The model proposed in this study provides a detailed Stress analysis of the inclusion which is required to correctly interpret the data collected through the optical fiber and deduce Stresses experienced by the host material.

George K. Haritos - One of the best experts on this subject based on the ideXlab platform.

  • on the use of critical distance theories for the prediction of the high cycle fatigue limit Stress in notched ti 6al 4v
    International Journal of Fatigue, 2005
    Co-Authors: David B Lanning, Theodore Nicholas, George K. Haritos
    Abstract:

    Abstract Methods are investigated for predicting the high cycle fatigue (HCF) lives of notched cylindrical Ti–6Al–4V specimens using critical distance concepts that employ the Stress distribution in the vicinity of the notch. Cylindrical fatigue specimens had circumferential V-notches with a range of Elastic Stress Concentration factors ( k t =1.97–4.07). Notched and unnotched specimens were cycled to failure using a step-loading technique to generate points on a Haigh (Goodman) diagram for a constant fatigue life of 10 6 cycles. Finite element solutions were generated to provide Stress distributions for the notched gage sections. The Stress distributions were used in the search for a critical distance over which the quantities of mean Stress, Stress range, or Elastic strain energy may contribute to the fatigue process and can be correlated to similar quantities from smooth, unnotched specimens. If the decrease in the local Stress ratio at the notch root for high applied Stress ratio is accounted for in the analysis, trends independent of applied Stress ratio were found in the calculated critical distances. Predictions based upon the results gave accuracy to within 12% of the experimental fatigue limit Stresses and illustrate the method has promise for use in fatigue design of Ti–6Al–4V components.

  • Notch size effects in HCF behavior of Ti–6Al–4V☆
    International Journal of Fatigue, 1999
    Co-Authors: George K. Haritos, Theodore Nicholas, David B Lanning
    Abstract:

    Abstract The high cycle fatigue (HCF) behavior of Ti–6Al–4V is investigated for cylindrical specimens having three sizes of geometrically similar circumferential V-notches, each with an Elastic Stress Concentration factor, K t , of approximately 2.78. A step loading technique for obtaining a point on a constant life (10 6 cycles) Haigh diagram from a single test specimen was implemented. Tests were performed at Stress ratios of R =0.1, 0.5, and 0.8 for specimens machined from two different product forms of Ti–6Al–4V, bar and plate forgings. Results indicate that while there is a definite notch size effect in the Ti–6Al–4V bar within the range of notch sizes tested, little or no such effect exists in the plate.