The Experts below are selected from a list of 18876 Experts worldwide ranked by ideXlab platform

Tomasz Wierzbicki - One of the best experts on this subject based on the ideXlab platform.

  • prediction of Plane Strain fracture of ahss sheets with post initiation softening
    International Journal of Solids and Structures, 2010
    Co-Authors: Tomasz Wierzbicki
    Abstract:

    Abstract In this investigation, the three-parameter Modified Mohr–Coulomb (MMC) fracture model and the determination of the material parameters are briefly described. The formulation of the post-initiation behavior is proposed by defining both the explicit softening law and the incremental damage evolution law. As opposed to the existing attempts to simulate slant fracture with material weakening before crack formation, softening is assumed to occur only in the post-initiation range. The justification of this assumption can be provided by the interrupted fracture tests, for example, Spencer et al. (2002) . Element deletion with a gradual loss of strength is used to simulate crack propagation after fracture initiation. The main emphasis of the paper is the numerical prediction of slant fracture which is almost always observed in thin sheets. For that purpose, VUMAT subroutines of ABAQUS are coded with post-initiation behavior for both shell Elements and Plane Strain Elements. Fracture of flat-grooved tensile specimens cut from advanced high strength steel (AHSS) sheets are simulated by 2D Plane Strain Element and shell Element models.

  • prediction of Plane Strain fracture of ahss sheets with post initiation softening
    International Journal of Solids and Structures, 2010
    Co-Authors: Yaning Li, Tomasz Wierzbicki
    Abstract:

    Abstract In this investigation, the three-parameter Modified Mohr–Coulomb (MMC) fracture model and the determination of the material parameters are briefly described. The formulation of the post-initiation behavior is proposed by defining both the explicit softening law and the incremental damage evolution law. As opposed to the existing attempts to simulate slant fracture with material weakening before crack formation, softening is assumed to occur only in the post-initiation range. The justification of this assumption can be provided by the interrupted fracture tests, for example, Spencer et al. (2002) . Element deletion with a gradual loss of strength is used to simulate crack propagation after fracture initiation. The main emphasis of the paper is the numerical prediction of slant fracture which is almost always observed in thin sheets. For that purpose, VUMAT subroutines of ABAQUS are coded with post-initiation behavior for both shell Elements and Plane Strain Elements. Fracture of flat-grooved tensile specimens cut from advanced high strength steel (AHSS) sheets are simulated by 2D Plane Strain Element and shell Element models.

Yaning Li - One of the best experts on this subject based on the ideXlab platform.

  • prediction of Plane Strain fracture of ahss sheets with post initiation softening
    International Journal of Solids and Structures, 2010
    Co-Authors: Yaning Li, Tomasz Wierzbicki
    Abstract:

    Abstract In this investigation, the three-parameter Modified Mohr–Coulomb (MMC) fracture model and the determination of the material parameters are briefly described. The formulation of the post-initiation behavior is proposed by defining both the explicit softening law and the incremental damage evolution law. As opposed to the existing attempts to simulate slant fracture with material weakening before crack formation, softening is assumed to occur only in the post-initiation range. The justification of this assumption can be provided by the interrupted fracture tests, for example, Spencer et al. (2002) . Element deletion with a gradual loss of strength is used to simulate crack propagation after fracture initiation. The main emphasis of the paper is the numerical prediction of slant fracture which is almost always observed in thin sheets. For that purpose, VUMAT subroutines of ABAQUS are coded with post-initiation behavior for both shell Elements and Plane Strain Elements. Fracture of flat-grooved tensile specimens cut from advanced high strength steel (AHSS) sheets are simulated by 2D Plane Strain Element and shell Element models.

Chunhsiung Huang - One of the best experts on this subject based on the ideXlab platform.

  • the influence of inserting a fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics
    Clinical Biomechanics, 2001
    Co-Authors: Jiannjong Liau, Chengkung Cheng, Chunhsiung Huang
    Abstract:

    Abstract Objective. To investigate the influence of inserting a Fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics. Design. A finite Element analysis was used to investigate the alteration of contact characteristics of the tibiofemoral joint due to inserting a pressure sensitive film between the contacting surfaces. Background. The discrepancy between actual contact behaviors of tibiofemoral joint of knee prosthesis and the measurement using Fuji pressure sensitive film was not discussed extensively. The change of direct contact circumstance of the tibiofemoral joint due to inserting a pressure sensitive film was not well reported. Method. A two-dimensional finite Element model of the tibiofemoral joint of knee prosthesis in the sagittal Plane was constructed. Four different radii of the femoral component were used to investigate the conformity effect. Two-layers of Plane Strain Element were used to model the pressure sensitive film. The influence of inserting a pressure sensitive film on the actual contact characteristics was analyzed by comparing the results of the change in contact radius. Results. Inserting a pressure sensitive film between contacting surfaces would disturb the original contact behaviors, especially in the lowest conformity design. The maximum difference of contact radius between the model simulating actual contact circumstance and the model with inserting a pressure sensitive film between contacting surface was 77% in the lowest conformity condition at the smallest load. Conclusions. This study proposes a quantitative analysis of contact characteristics in the tibiofemoral joint of knee prosthesis between the models with and without inserting a pressure sensitive film into the contact surface. The measurement of contact area in artificial tibiofemoral joints by using Fuji pressure sensitive film is always overestimated its true contact area by 14–77%. Relevance This study revealed the measurement of contact characteristics of artificial tibiofemoral joints by using Fuji pressure sensitive film which depends on not only the applied load, but also the conformity and material properties of the contact surface. Therefore, the information of the conformity and material properties of the contact surface should be provided as well as the applied load wherever a measurement of contact characteristics using Fuji pressure sensitive film is analyzed and interpreted.

Jiannjong Liau - One of the best experts on this subject based on the ideXlab platform.

  • the influence of inserting a fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics
    Clinical Biomechanics, 2001
    Co-Authors: Jiannjong Liau, Chengkung Cheng, Chunhsiung Huang
    Abstract:

    Abstract Objective. To investigate the influence of inserting a Fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics. Design. A finite Element analysis was used to investigate the alteration of contact characteristics of the tibiofemoral joint due to inserting a pressure sensitive film between the contacting surfaces. Background. The discrepancy between actual contact behaviors of tibiofemoral joint of knee prosthesis and the measurement using Fuji pressure sensitive film was not discussed extensively. The change of direct contact circumstance of the tibiofemoral joint due to inserting a pressure sensitive film was not well reported. Method. A two-dimensional finite Element model of the tibiofemoral joint of knee prosthesis in the sagittal Plane was constructed. Four different radii of the femoral component were used to investigate the conformity effect. Two-layers of Plane Strain Element were used to model the pressure sensitive film. The influence of inserting a pressure sensitive film on the actual contact characteristics was analyzed by comparing the results of the change in contact radius. Results. Inserting a pressure sensitive film between contacting surfaces would disturb the original contact behaviors, especially in the lowest conformity design. The maximum difference of contact radius between the model simulating actual contact circumstance and the model with inserting a pressure sensitive film between contacting surface was 77% in the lowest conformity condition at the smallest load. Conclusions. This study proposes a quantitative analysis of contact characteristics in the tibiofemoral joint of knee prosthesis between the models with and without inserting a pressure sensitive film into the contact surface. The measurement of contact area in artificial tibiofemoral joints by using Fuji pressure sensitive film is always overestimated its true contact area by 14–77%. Relevance This study revealed the measurement of contact characteristics of artificial tibiofemoral joints by using Fuji pressure sensitive film which depends on not only the applied load, but also the conformity and material properties of the contact surface. Therefore, the information of the conformity and material properties of the contact surface should be provided as well as the applied load wherever a measurement of contact characteristics using Fuji pressure sensitive film is analyzed and interpreted.

Chengkung Cheng - One of the best experts on this subject based on the ideXlab platform.

  • the influence of inserting a fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics
    Clinical Biomechanics, 2001
    Co-Authors: Jiannjong Liau, Chengkung Cheng, Chunhsiung Huang
    Abstract:

    Abstract Objective. To investigate the influence of inserting a Fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics. Design. A finite Element analysis was used to investigate the alteration of contact characteristics of the tibiofemoral joint due to inserting a pressure sensitive film between the contacting surfaces. Background. The discrepancy between actual contact behaviors of tibiofemoral joint of knee prosthesis and the measurement using Fuji pressure sensitive film was not discussed extensively. The change of direct contact circumstance of the tibiofemoral joint due to inserting a pressure sensitive film was not well reported. Method. A two-dimensional finite Element model of the tibiofemoral joint of knee prosthesis in the sagittal Plane was constructed. Four different radii of the femoral component were used to investigate the conformity effect. Two-layers of Plane Strain Element were used to model the pressure sensitive film. The influence of inserting a pressure sensitive film on the actual contact characteristics was analyzed by comparing the results of the change in contact radius. Results. Inserting a pressure sensitive film between contacting surfaces would disturb the original contact behaviors, especially in the lowest conformity design. The maximum difference of contact radius between the model simulating actual contact circumstance and the model with inserting a pressure sensitive film between contacting surface was 77% in the lowest conformity condition at the smallest load. Conclusions. This study proposes a quantitative analysis of contact characteristics in the tibiofemoral joint of knee prosthesis between the models with and without inserting a pressure sensitive film into the contact surface. The measurement of contact area in artificial tibiofemoral joints by using Fuji pressure sensitive film is always overestimated its true contact area by 14–77%. Relevance This study revealed the measurement of contact characteristics of artificial tibiofemoral joints by using Fuji pressure sensitive film which depends on not only the applied load, but also the conformity and material properties of the contact surface. Therefore, the information of the conformity and material properties of the contact surface should be provided as well as the applied load wherever a measurement of contact characteristics using Fuji pressure sensitive film is analyzed and interpreted.