The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
Costin D. Untaroiu - One of the best experts on this subject based on the ideXlab platform.
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A Numerical Investigation of Mid-femoral Injury Tolerance in Axial Compression and Bending Loading
International Journal of Crashworthiness, 2010Co-Authors: Costin D. UntaroiuAbstract:Bone fractures occur frequently at mid-Shaft femoral site of the front seat vehicle occupants during frontal and offset automotive crashes. A numerical investigation of femoral Shaft Tolerance under axial and bending loading corresponding to traffic accidents is presented in the current study. A subject specific finite element (FE) model of a femur is developed and the parameters of two material models of cortical bone (isotropic elastic–plastic and elastic transversally isotropic) are identified based on three-point bending test data using optimisation techniques. A Monte Carlo analysis is performed on a surface approximation of the optimised models over a domain of +/− 20% of the optimised parameter values and showed that the elastic moduli of femur are the most influential parameters on the bone stiffness curve prior to bone fracture. The mid-Shaft femoral Tolerance curves demonstrate sensitivity with respect to the impact direction of transversal load due to the initial curvature of the femur, but ins...
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A Finite Element Analysis of Mid-Shaft Femoral Tolerance under Combined Axial-Bending Loading
2008Co-Authors: Costin D. Untaroiu, Dan R. Genovese, Johan Ivarsson, Jeffrey Richard CrandallAbstract:Bone fractures occur frequently at mid-Shaft femoral site during frontal and offset automotive crashes. Because these injuries are expensive, it is crucial to understand the injury mechanisms if this injury is to be prevented. The experimental investigation of femoral Shaft Tolerance under loading corresponding to real world accidents requires a challenging test setup that allows applying external loads in controlled conditions, mimics the boundary conditions of the femur, and measures the loads at the mid-Shaft cross-section of the femur. In addition, the variability of mechanical and structural properties of the specimens complicates the determination of the injury Tolerance of the femur under different loading conditions. A numerical alternative is presented in the current study. First, a subject specific finite element model of a femur is developed based on medical images. Then, the parameters of two material models frequently used to approximate the cortical bone properties are identified using the Successive Response Surface Methodology in the ranges reported in the literature. The objective function is defined based on the impact force data recorded during a three-point bending test and its corresponding numerical simulations. The polynomial meta-models implemented in LS-Opt converge at close values of the material parameters suggesting good performance of the heuristic design search in the current identification problem. The femoral Tolerance at mid-Shaft location is determined using a virtual test setup that applies combined axial –sagittal bending loading through an axial preload along the knee-hip line and a transversal impact load at the mid-Shaft site along anterior-posterior or posterior-anterior directions. The femoral Tolerance curves calculated based on external loads show sensitivity with respect to the impact direction of transversal load due to the initial curvature of the femur, but insignificant dependence on the material mode, or the failure criteria used for femoral cortical bone. In addition to suggesting a numerical approach that uses finite element simulations and optimization techniques to determine the injury Tolerance of long bones, the results highlight the predominant role of the bending loading in a combined loading of the femur.
Jeffrey Richard Crandall - One of the best experts on this subject based on the ideXlab platform.
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A Finite Element Analysis of Mid-Shaft Femoral Tolerance under Combined Axial-Bending Loading
2008Co-Authors: Costin D. Untaroiu, Dan R. Genovese, Johan Ivarsson, Jeffrey Richard CrandallAbstract:Bone fractures occur frequently at mid-Shaft femoral site during frontal and offset automotive crashes. Because these injuries are expensive, it is crucial to understand the injury mechanisms if this injury is to be prevented. The experimental investigation of femoral Shaft Tolerance under loading corresponding to real world accidents requires a challenging test setup that allows applying external loads in controlled conditions, mimics the boundary conditions of the femur, and measures the loads at the mid-Shaft cross-section of the femur. In addition, the variability of mechanical and structural properties of the specimens complicates the determination of the injury Tolerance of the femur under different loading conditions. A numerical alternative is presented in the current study. First, a subject specific finite element model of a femur is developed based on medical images. Then, the parameters of two material models frequently used to approximate the cortical bone properties are identified using the Successive Response Surface Methodology in the ranges reported in the literature. The objective function is defined based on the impact force data recorded during a three-point bending test and its corresponding numerical simulations. The polynomial meta-models implemented in LS-Opt converge at close values of the material parameters suggesting good performance of the heuristic design search in the current identification problem. The femoral Tolerance at mid-Shaft location is determined using a virtual test setup that applies combined axial –sagittal bending loading through an axial preload along the knee-hip line and a transversal impact load at the mid-Shaft site along anterior-posterior or posterior-anterior directions. The femoral Tolerance curves calculated based on external loads show sensitivity with respect to the impact direction of transversal load due to the initial curvature of the femur, but insignificant dependence on the material mode, or the failure criteria used for femoral cortical bone. In addition to suggesting a numerical approach that uses finite element simulations and optimization techniques to determine the injury Tolerance of long bones, the results highlight the predominant role of the bending loading in a combined loading of the femur.
Dan R. Genovese - One of the best experts on this subject based on the ideXlab platform.
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A Finite Element Analysis of Mid-Shaft Femoral Tolerance under Combined Axial-Bending Loading
2008Co-Authors: Costin D. Untaroiu, Dan R. Genovese, Johan Ivarsson, Jeffrey Richard CrandallAbstract:Bone fractures occur frequently at mid-Shaft femoral site during frontal and offset automotive crashes. Because these injuries are expensive, it is crucial to understand the injury mechanisms if this injury is to be prevented. The experimental investigation of femoral Shaft Tolerance under loading corresponding to real world accidents requires a challenging test setup that allows applying external loads in controlled conditions, mimics the boundary conditions of the femur, and measures the loads at the mid-Shaft cross-section of the femur. In addition, the variability of mechanical and structural properties of the specimens complicates the determination of the injury Tolerance of the femur under different loading conditions. A numerical alternative is presented in the current study. First, a subject specific finite element model of a femur is developed based on medical images. Then, the parameters of two material models frequently used to approximate the cortical bone properties are identified using the Successive Response Surface Methodology in the ranges reported in the literature. The objective function is defined based on the impact force data recorded during a three-point bending test and its corresponding numerical simulations. The polynomial meta-models implemented in LS-Opt converge at close values of the material parameters suggesting good performance of the heuristic design search in the current identification problem. The femoral Tolerance at mid-Shaft location is determined using a virtual test setup that applies combined axial –sagittal bending loading through an axial preload along the knee-hip line and a transversal impact load at the mid-Shaft site along anterior-posterior or posterior-anterior directions. The femoral Tolerance curves calculated based on external loads show sensitivity with respect to the impact direction of transversal load due to the initial curvature of the femur, but insignificant dependence on the material mode, or the failure criteria used for femoral cortical bone. In addition to suggesting a numerical approach that uses finite element simulations and optimization techniques to determine the injury Tolerance of long bones, the results highlight the predominant role of the bending loading in a combined loading of the femur.
Johan Ivarsson - One of the best experts on this subject based on the ideXlab platform.
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A Finite Element Analysis of Mid-Shaft Femoral Tolerance under Combined Axial-Bending Loading
2008Co-Authors: Costin D. Untaroiu, Dan R. Genovese, Johan Ivarsson, Jeffrey Richard CrandallAbstract:Bone fractures occur frequently at mid-Shaft femoral site during frontal and offset automotive crashes. Because these injuries are expensive, it is crucial to understand the injury mechanisms if this injury is to be prevented. The experimental investigation of femoral Shaft Tolerance under loading corresponding to real world accidents requires a challenging test setup that allows applying external loads in controlled conditions, mimics the boundary conditions of the femur, and measures the loads at the mid-Shaft cross-section of the femur. In addition, the variability of mechanical and structural properties of the specimens complicates the determination of the injury Tolerance of the femur under different loading conditions. A numerical alternative is presented in the current study. First, a subject specific finite element model of a femur is developed based on medical images. Then, the parameters of two material models frequently used to approximate the cortical bone properties are identified using the Successive Response Surface Methodology in the ranges reported in the literature. The objective function is defined based on the impact force data recorded during a three-point bending test and its corresponding numerical simulations. The polynomial meta-models implemented in LS-Opt converge at close values of the material parameters suggesting good performance of the heuristic design search in the current identification problem. The femoral Tolerance at mid-Shaft location is determined using a virtual test setup that applies combined axial –sagittal bending loading through an axial preload along the knee-hip line and a transversal impact load at the mid-Shaft site along anterior-posterior or posterior-anterior directions. The femoral Tolerance curves calculated based on external loads show sensitivity with respect to the impact direction of transversal load due to the initial curvature of the femur, but insignificant dependence on the material mode, or the failure criteria used for femoral cortical bone. In addition to suggesting a numerical approach that uses finite element simulations and optimization techniques to determine the injury Tolerance of long bones, the results highlight the predominant role of the bending loading in a combined loading of the femur.
Geng Wang - One of the best experts on this subject based on the ideXlab platform.
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IECON - Mechanical resonance suppression and Shaft torque limitation of two-mass drive system based on model predictive control
IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society, 2014Co-Authors: Can Wang, Ming Yang, Geng WangAbstract:The flexibility of transmission mechanisms in two-mass servo system can lead to its mechanical resonance. If the oscillation amplitude is beyond the Shaft Tolerance, it will lead to system insecurity problems. In this paper, the model of transmission mechanisms is firstly established, and based on that, four strategies: engineering design, pole placement method, Shaft torque state feedback method and model predictive control are studied to suppress mechanical vibration and protect the safety of transmission. Simulation results show the advantages and disadvantages of the four strategies, meanwhile confirm MPC as the optimal method. MPC can suppress mechanical resonance, limit the amplitude of the Shaft torque and allow the system to complete the transient process with maximum acceleration, taking dynamic performance and security into account at the same time.