The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Mary L Bouxsein - One of the best experts on this subject based on the ideXlab platform.

  • the effect of thoracic kyphosis and sagittal plane alignment on vertebral Compressive Loading
    Journal of Bone and Mineral Research, 2012
    Co-Authors: Alexander G Bruno, Dennis E Anderson, John Dagostino, Mary L Bouxsein
    Abstract:

    To better understand the biomechanical mechanisms underlying the association between hyperkyphosis of the thoracic spine and risk of vertebral fracture and other degenerative spinal pathology, we used a previously validated musculoskeletal model of the spine to determine how thoracic kyphosis angle and spinal posture affect vertebral Compressive Loading. We simulated an age-related increase in thoracic kyphosis (T1-T12 Cobb angle 50° to 75°) during two different activities (relaxed standing and standing with 5 kg weights in the hands) and three different posture conditions: 1) an increase in thoracic kyphosis with no postural adjustment (uncompensated posture), 2) an increase in thoracic kyphosis with a concomitant increase in pelvic tilt that maintains a stable center of mass and horizontal eye gaze (compensated posture), and 3) an increase in thoracic kyphosis with a concomitant increase in lumbar lordosis that also maintains a stable center of mass and horizontal eye gaze (congruent posture). For all posture conditions, Compressive Loading increased with increasing thoracic kyphosis, with Loading increasing more in the thoracolumbar and lumbar regions than in the mid-thoracic region. Loading increased the most for the uncompensated posture, followed by the compensated posture, with the congruent posture almost completely mitigating any increases in Loading with increased thoracic kyphosis. These findings indicate that thoracic kyphosis and spinal posture both influence vertebral Loading during daily activities, implying that thoracic kyphosis measurements alone are not sufficient to characterize the impact of spinal curvature on vertebral Loading.

  • the effect of thoracic kyphosis and sagittal plane alignment on vertebral Compressive Loading
    Journal of Bone and Mineral Research, 2012
    Co-Authors: Alexander G Bruno, Dennis E Anderson, John Dagostino, Mary L Bouxsein
    Abstract:

    To better understand the biomechanical mechanisms underlying the association between hyperkyphosis of the thoracic spine and risk of vertebral fracture and other degenerative spinal pathology, we used a previously validated musculoskeletal model of the spine to determine how thoracic kyphosis angle and spinal posture affect vertebral Compressive Loading. We simulated an age-related increase in thoracic kyphosis (T(1) -T(12) Cobb angle 50-75 degrees) during two different activities (relaxed standing and standing with 5-kg weights in the hands) and three different posture conditions: (1) an increase in thoracic kyphosis with no postural adjustment (uncompensated posture); (2) an increase in thoracic kyphosis with a concomitant increase in pelvic tilt that maintains a stable center of mass and horizontal eye gaze (compensated posture); and (3) an increase in thoracic kyphosis with a concomitant increase in lumbar lordosis that also maintains a stable center of mass and horizontal eye gaze (congruent posture). For all posture conditions, Compressive Loading increased with increasing thoracic kyphosis, with Loading increasing more in the thoracolumbar and lumbar regions than in the mid-thoracic region. Loading increased the most for the uncompensated posture, followed by the compensated posture, with the congruent posture almost completely mitigating any increases in Loading with increased thoracic kyphosis. These findings indicate that both thoracic kyphosis and spinal posture influence vertebral Loading during daily activities, implying that thoracic kyphosis measurements alone are not sufficient to characterize the impact of spinal curvature on vertebral Loading.

Alexander G Bruno - One of the best experts on this subject based on the ideXlab platform.

  • the effect of thoracic kyphosis and sagittal plane alignment on vertebral Compressive Loading
    Journal of Bone and Mineral Research, 2012
    Co-Authors: Alexander G Bruno, Dennis E Anderson, John Dagostino, Mary L Bouxsein
    Abstract:

    To better understand the biomechanical mechanisms underlying the association between hyperkyphosis of the thoracic spine and risk of vertebral fracture and other degenerative spinal pathology, we used a previously validated musculoskeletal model of the spine to determine how thoracic kyphosis angle and spinal posture affect vertebral Compressive Loading. We simulated an age-related increase in thoracic kyphosis (T1-T12 Cobb angle 50° to 75°) during two different activities (relaxed standing and standing with 5 kg weights in the hands) and three different posture conditions: 1) an increase in thoracic kyphosis with no postural adjustment (uncompensated posture), 2) an increase in thoracic kyphosis with a concomitant increase in pelvic tilt that maintains a stable center of mass and horizontal eye gaze (compensated posture), and 3) an increase in thoracic kyphosis with a concomitant increase in lumbar lordosis that also maintains a stable center of mass and horizontal eye gaze (congruent posture). For all posture conditions, Compressive Loading increased with increasing thoracic kyphosis, with Loading increasing more in the thoracolumbar and lumbar regions than in the mid-thoracic region. Loading increased the most for the uncompensated posture, followed by the compensated posture, with the congruent posture almost completely mitigating any increases in Loading with increased thoracic kyphosis. These findings indicate that thoracic kyphosis and spinal posture both influence vertebral Loading during daily activities, implying that thoracic kyphosis measurements alone are not sufficient to characterize the impact of spinal curvature on vertebral Loading.

  • the effect of thoracic kyphosis and sagittal plane alignment on vertebral Compressive Loading
    Journal of Bone and Mineral Research, 2012
    Co-Authors: Alexander G Bruno, Dennis E Anderson, John Dagostino, Mary L Bouxsein
    Abstract:

    To better understand the biomechanical mechanisms underlying the association between hyperkyphosis of the thoracic spine and risk of vertebral fracture and other degenerative spinal pathology, we used a previously validated musculoskeletal model of the spine to determine how thoracic kyphosis angle and spinal posture affect vertebral Compressive Loading. We simulated an age-related increase in thoracic kyphosis (T(1) -T(12) Cobb angle 50-75 degrees) during two different activities (relaxed standing and standing with 5-kg weights in the hands) and three different posture conditions: (1) an increase in thoracic kyphosis with no postural adjustment (uncompensated posture); (2) an increase in thoracic kyphosis with a concomitant increase in pelvic tilt that maintains a stable center of mass and horizontal eye gaze (compensated posture); and (3) an increase in thoracic kyphosis with a concomitant increase in lumbar lordosis that also maintains a stable center of mass and horizontal eye gaze (congruent posture). For all posture conditions, Compressive Loading increased with increasing thoracic kyphosis, with Loading increasing more in the thoracolumbar and lumbar regions than in the mid-thoracic region. Loading increased the most for the uncompensated posture, followed by the compensated posture, with the congruent posture almost completely mitigating any increases in Loading with increased thoracic kyphosis. These findings indicate that both thoracic kyphosis and spinal posture influence vertebral Loading during daily activities, implying that thoracic kyphosis measurements alone are not sufficient to characterize the impact of spinal curvature on vertebral Loading.

Jeom Kee Paik - One of the best experts on this subject based on the ideXlab platform.

  • full scale collapse testing of a steel stiffened plate structure under cyclic axial Compressive Loading
    Structures, 2020
    Co-Authors: Jeom Kee Paik, Dae Kyeom Park, Jonas W Ringsberg
    Abstract:

    Plate panels of ships and floating offshore structures are likely subjected to cyclic loads arising from waves at sea. Depending on sea states, e.g., whipping in harsh sea states, the maximum amplitude of the cyclic loads may reach over 70% of ultimate loads. Of concerns is how the cyclic loads will affect the ultimate strength compared to a case of monotonically increasing loads. The aim of this paper is to experimentally investigate the ultimate strength characteristics of a steel stiffened plate structure under cyclic axial-Compressive Loading. A full-scale collapse testing in association with bottom structures of an as-built 1,900 TEU containership was conducted. It is concluded that the effects of cyclic Loading on the ultimate Compressive strength of steel stiffened plate structures are small as far as fatigue damages are not suffered due to the small number of load cycles and/or local structural members do not reach the ultimate strength during cyclic axial-Compressive Loading. Details of the test database are documented, which will be useful to validate computational models for the ultimate strength analysis.

  • full scale collapse testing of a steel stiffened plate structure under axial Compressive Loading at a temperature of 80 c
    Ships and Offshore Structures, 2020
    Co-Authors: Jeom Kee Paik, Dae Kyeom Park, Jonas W Ringsberg
    Abstract:

    The aim of the paper was to develop a test database of the ultimate strength characteristics of full-scale steel stiffened plate structures under axial Compressive Loading at a temperature of −80°C...

  • full scale collapse testing of a steel stiffened plate structure under axial Compressive Loading triggered by brittle fracture at cryogenic condition
    Ships and Offshore Structures, 2020
    Co-Authors: Jeom Kee Paik, Dae Kyeom Park, Jonas W Ringsberg
    Abstract:

    This paper is a sequel to the authors’ earlier article (Paik et al. 2020a, Full-scale collapse testing of a steel stiffened plate structure under cyclic axial-Compressive Loading, Structures, https://doi.org/10.1016/j.istruc.2020.05.026). The aim of the paper was to present a test data on the ultimate Compressive strength characteristics of a full-scale steel stiffened plate structure at cryogenic condition which may be due to unwanted release of liquefied gases. Steel plate panels of an as-built containership carrying 1,900 TEU were referenced for this purpose. The test structure was fabricated in a shipyard using exactly the same welding technology as used in today’s shipbuilding industry. It is observed that the test structure reaches the ultimate limit states triggered by brittle fracture, which is totally different from typical collapse modes at room temperature. Details of the test database are documented as they can be used to validate computational models for the structural crashworthiness analysis involving brittle fracture at cryogenic condition.

  • ultimate strength of steel plates with a single circular hole under axial Compressive Loading along short edges
    Ships and Offshore Structures, 2007
    Co-Authors: Jeom Kee Paik
    Abstract:

    Abstract The aim of the present study is to investigate the ultimate strength characteristics of steel plates with a single circular hole under axial Compressive Loading along short edges, which is a primary action type arising from vertical or horizontal hull girder bending moments of ships and ship-shaped offshore structures. The plates are considered to be simply supported along all (four) edges and kept straight. The circular hole is located at the center of the plate. A series of ANSYS nonlinear finite element analyses (FEA) are undertaken with varying the hole size (diameter) as well as plate dimensions (plate aspect ratio and thickness). By regression analysis of the FEA results obtained, a closed-form empirical formula for the ultimate longitudinal Compressive strength of perforated plates, which can be useful for first-cut strength estimations and reliability analyses, is derived. The accuracy of the ultimate strength formula developed is verified by a comparison with more refined nonlinear FEA r...

Dennis E Anderson - One of the best experts on this subject based on the ideXlab platform.

  • the effect of thoracic kyphosis and sagittal plane alignment on vertebral Compressive Loading
    Journal of Bone and Mineral Research, 2012
    Co-Authors: Alexander G Bruno, Dennis E Anderson, John Dagostino, Mary L Bouxsein
    Abstract:

    To better understand the biomechanical mechanisms underlying the association between hyperkyphosis of the thoracic spine and risk of vertebral fracture and other degenerative spinal pathology, we used a previously validated musculoskeletal model of the spine to determine how thoracic kyphosis angle and spinal posture affect vertebral Compressive Loading. We simulated an age-related increase in thoracic kyphosis (T1-T12 Cobb angle 50° to 75°) during two different activities (relaxed standing and standing with 5 kg weights in the hands) and three different posture conditions: 1) an increase in thoracic kyphosis with no postural adjustment (uncompensated posture), 2) an increase in thoracic kyphosis with a concomitant increase in pelvic tilt that maintains a stable center of mass and horizontal eye gaze (compensated posture), and 3) an increase in thoracic kyphosis with a concomitant increase in lumbar lordosis that also maintains a stable center of mass and horizontal eye gaze (congruent posture). For all posture conditions, Compressive Loading increased with increasing thoracic kyphosis, with Loading increasing more in the thoracolumbar and lumbar regions than in the mid-thoracic region. Loading increased the most for the uncompensated posture, followed by the compensated posture, with the congruent posture almost completely mitigating any increases in Loading with increased thoracic kyphosis. These findings indicate that thoracic kyphosis and spinal posture both influence vertebral Loading during daily activities, implying that thoracic kyphosis measurements alone are not sufficient to characterize the impact of spinal curvature on vertebral Loading.

  • the effect of thoracic kyphosis and sagittal plane alignment on vertebral Compressive Loading
    Journal of Bone and Mineral Research, 2012
    Co-Authors: Alexander G Bruno, Dennis E Anderson, John Dagostino, Mary L Bouxsein
    Abstract:

    To better understand the biomechanical mechanisms underlying the association between hyperkyphosis of the thoracic spine and risk of vertebral fracture and other degenerative spinal pathology, we used a previously validated musculoskeletal model of the spine to determine how thoracic kyphosis angle and spinal posture affect vertebral Compressive Loading. We simulated an age-related increase in thoracic kyphosis (T(1) -T(12) Cobb angle 50-75 degrees) during two different activities (relaxed standing and standing with 5-kg weights in the hands) and three different posture conditions: (1) an increase in thoracic kyphosis with no postural adjustment (uncompensated posture); (2) an increase in thoracic kyphosis with a concomitant increase in pelvic tilt that maintains a stable center of mass and horizontal eye gaze (compensated posture); and (3) an increase in thoracic kyphosis with a concomitant increase in lumbar lordosis that also maintains a stable center of mass and horizontal eye gaze (congruent posture). For all posture conditions, Compressive Loading increased with increasing thoracic kyphosis, with Loading increasing more in the thoracolumbar and lumbar regions than in the mid-thoracic region. Loading increased the most for the uncompensated posture, followed by the compensated posture, with the congruent posture almost completely mitigating any increases in Loading with increased thoracic kyphosis. These findings indicate that both thoracic kyphosis and spinal posture influence vertebral Loading during daily activities, implying that thoracic kyphosis measurements alone are not sufficient to characterize the impact of spinal curvature on vertebral Loading.

Jonas W Ringsberg - One of the best experts on this subject based on the ideXlab platform.

  • full scale collapse testing of a steel stiffened plate structure under cyclic axial Compressive Loading
    Structures, 2020
    Co-Authors: Jeom Kee Paik, Dae Kyeom Park, Jonas W Ringsberg
    Abstract:

    Plate panels of ships and floating offshore structures are likely subjected to cyclic loads arising from waves at sea. Depending on sea states, e.g., whipping in harsh sea states, the maximum amplitude of the cyclic loads may reach over 70% of ultimate loads. Of concerns is how the cyclic loads will affect the ultimate strength compared to a case of monotonically increasing loads. The aim of this paper is to experimentally investigate the ultimate strength characteristics of a steel stiffened plate structure under cyclic axial-Compressive Loading. A full-scale collapse testing in association with bottom structures of an as-built 1,900 TEU containership was conducted. It is concluded that the effects of cyclic Loading on the ultimate Compressive strength of steel stiffened plate structures are small as far as fatigue damages are not suffered due to the small number of load cycles and/or local structural members do not reach the ultimate strength during cyclic axial-Compressive Loading. Details of the test database are documented, which will be useful to validate computational models for the ultimate strength analysis.

  • full scale collapse testing of a steel stiffened plate structure under axial Compressive Loading at a temperature of 80 c
    Ships and Offshore Structures, 2020
    Co-Authors: Jeom Kee Paik, Dae Kyeom Park, Jonas W Ringsberg
    Abstract:

    The aim of the paper was to develop a test database of the ultimate strength characteristics of full-scale steel stiffened plate structures under axial Compressive Loading at a temperature of −80°C...

  • full scale collapse testing of a steel stiffened plate structure under axial Compressive Loading triggered by brittle fracture at cryogenic condition
    Ships and Offshore Structures, 2020
    Co-Authors: Jeom Kee Paik, Dae Kyeom Park, Jonas W Ringsberg
    Abstract:

    This paper is a sequel to the authors’ earlier article (Paik et al. 2020a, Full-scale collapse testing of a steel stiffened plate structure under cyclic axial-Compressive Loading, Structures, https://doi.org/10.1016/j.istruc.2020.05.026). The aim of the paper was to present a test data on the ultimate Compressive strength characteristics of a full-scale steel stiffened plate structure at cryogenic condition which may be due to unwanted release of liquefied gases. Steel plate panels of an as-built containership carrying 1,900 TEU were referenced for this purpose. The test structure was fabricated in a shipyard using exactly the same welding technology as used in today’s shipbuilding industry. It is observed that the test structure reaches the ultimate limit states triggered by brittle fracture, which is totally different from typical collapse modes at room temperature. Details of the test database are documented as they can be used to validate computational models for the structural crashworthiness analysis involving brittle fracture at cryogenic condition.