The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Maenghyo Cho - One of the best experts on this subject based on the ideXlab platform.
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Reduced-order modeling of nonlinear structural dynamical systems via element-wise stiffness Evaluation Procedure combined with hyper-reduction
Computational Mechanics, 2021Co-Authors: Jonggeon Lee, Jaehun Lee, Haeseong Cho, Euiyoung Kim, Maenghyo ChoAbstract:In nonlinear analysis, performing iterative inverse calculation and nonlinear system construction Procedures incurs expensive computational costs. This paper presents an element-wise stiffness Evaluation Procedure combined with hyper-reduction reduced-order modeling (HE-STEP ROM) method. The proposed approach constructs a non-intrusive reduced-order model based on an element-wise stiffness Evaluation Procedure (E-STEP) and hyper-reduction methods. Because the E-STEP evaluates nonlinear stiffness coefficients element-by-element using cubic polynomial, numerous number of polynomial variables are required. The number of variables directly affects the computational efficiency of the online and offline stages. Therefore, to enhance efficiency of the online/offline stages, the proposed method employs hyper-reduction method. By applying hyper-reduction, the full stiffness coefficients are approximated from the stiffness coefficients evaluated at a few sampling points. Subsequently, the number of polynomial equations and variables is prominently reduced, and the efficiency of the reduced system increases. The efficiency and accuracy of the proposed approach are validated via several structural dynamic problems with geometric and material nonlinearities.
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Equivalent model construction for a non-linear dynamic system based on an element-wise stiffness Evaluation Procedure and reduced analysis of the equivalent system
Computational Mechanics, 2017Co-Authors: Euiyoung Kim, Maenghyo ChoAbstract:In most non-linear analyses, the construction of a system matrix uses a large amount of computation time, comparable to the computation time required by the solving process. If the process for computing non-linear internal force matrices is substituted with an effective equivalent model that enables the bypass of numerical integrations and assembly processes used in matrix construction, efficiency can be greatly enhanced. A stiffness Evaluation Procedure (STEP) establishes non-linear internal force models using polynomial formulations of displacements. To efficiently identify an equivalent model, the method has evolved such that it is based on a reduced-order system. The reduction process, however, makes the equivalent model difficult to parameterize, which significantly affects the efficiency of the optimization process. In this paper, therefore, a new STEP, E-STEP, is proposed. Based on the element-wise nature of the finite element model, the stiffness Evaluation is carried out element-by-element in the full domain. Since the unit of computation for the stiffness Evaluation is restricted by element size, and since the computation is independent, the equivalent model can be constructed efficiently in parallel, even in the full domain. Due to the element-wise nature of the construction Procedure, the equivalent E-STEP model is easily characterized by design parameters. Various reduced-order modeling techniques can be applied to the equivalent system in a manner similar to how they are applied in the original system. The reduced-order model based on E-STEP is successfully demonstrated for the dynamic analyses of non-linear structural finite element systems under varying design parameters.
Euiyoung Kim - One of the best experts on this subject based on the ideXlab platform.
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Reduced-order modeling of nonlinear structural dynamical systems via element-wise stiffness Evaluation Procedure combined with hyper-reduction
Computational Mechanics, 2021Co-Authors: Jonggeon Lee, Jaehun Lee, Haeseong Cho, Euiyoung Kim, Maenghyo ChoAbstract:In nonlinear analysis, performing iterative inverse calculation and nonlinear system construction Procedures incurs expensive computational costs. This paper presents an element-wise stiffness Evaluation Procedure combined with hyper-reduction reduced-order modeling (HE-STEP ROM) method. The proposed approach constructs a non-intrusive reduced-order model based on an element-wise stiffness Evaluation Procedure (E-STEP) and hyper-reduction methods. Because the E-STEP evaluates nonlinear stiffness coefficients element-by-element using cubic polynomial, numerous number of polynomial variables are required. The number of variables directly affects the computational efficiency of the online and offline stages. Therefore, to enhance efficiency of the online/offline stages, the proposed method employs hyper-reduction method. By applying hyper-reduction, the full stiffness coefficients are approximated from the stiffness coefficients evaluated at a few sampling points. Subsequently, the number of polynomial equations and variables is prominently reduced, and the efficiency of the reduced system increases. The efficiency and accuracy of the proposed approach are validated via several structural dynamic problems with geometric and material nonlinearities.
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Equivalent model construction for a non-linear dynamic system based on an element-wise stiffness Evaluation Procedure and reduced analysis of the equivalent system
Computational Mechanics, 2017Co-Authors: Euiyoung Kim, Maenghyo ChoAbstract:In most non-linear analyses, the construction of a system matrix uses a large amount of computation time, comparable to the computation time required by the solving process. If the process for computing non-linear internal force matrices is substituted with an effective equivalent model that enables the bypass of numerical integrations and assembly processes used in matrix construction, efficiency can be greatly enhanced. A stiffness Evaluation Procedure (STEP) establishes non-linear internal force models using polynomial formulations of displacements. To efficiently identify an equivalent model, the method has evolved such that it is based on a reduced-order system. The reduction process, however, makes the equivalent model difficult to parameterize, which significantly affects the efficiency of the optimization process. In this paper, therefore, a new STEP, E-STEP, is proposed. Based on the element-wise nature of the finite element model, the stiffness Evaluation is carried out element-by-element in the full domain. Since the unit of computation for the stiffness Evaluation is restricted by element size, and since the computation is independent, the equivalent model can be constructed efficiently in parallel, even in the full domain. Due to the element-wise nature of the construction Procedure, the equivalent E-STEP model is easily characterized by design parameters. Various reduced-order modeling techniques can be applied to the equivalent system in a manner similar to how they are applied in the original system. The reduced-order model based on E-STEP is successfully demonstrated for the dynamic analyses of non-linear structural finite element systems under varying design parameters.
Jonggeon Lee - One of the best experts on this subject based on the ideXlab platform.
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Reduced-order modeling of nonlinear structural dynamical systems via element-wise stiffness Evaluation Procedure combined with hyper-reduction
Computational Mechanics, 2021Co-Authors: Jonggeon Lee, Jaehun Lee, Haeseong Cho, Euiyoung Kim, Maenghyo ChoAbstract:In nonlinear analysis, performing iterative inverse calculation and nonlinear system construction Procedures incurs expensive computational costs. This paper presents an element-wise stiffness Evaluation Procedure combined with hyper-reduction reduced-order modeling (HE-STEP ROM) method. The proposed approach constructs a non-intrusive reduced-order model based on an element-wise stiffness Evaluation Procedure (E-STEP) and hyper-reduction methods. Because the E-STEP evaluates nonlinear stiffness coefficients element-by-element using cubic polynomial, numerous number of polynomial variables are required. The number of variables directly affects the computational efficiency of the online and offline stages. Therefore, to enhance efficiency of the online/offline stages, the proposed method employs hyper-reduction method. By applying hyper-reduction, the full stiffness coefficients are approximated from the stiffness coefficients evaluated at a few sampling points. Subsequently, the number of polynomial equations and variables is prominently reduced, and the efficiency of the reduced system increases. The efficiency and accuracy of the proposed approach are validated via several structural dynamic problems with geometric and material nonlinearities.
Jaehun Lee - One of the best experts on this subject based on the ideXlab platform.
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Reduced-order modeling of nonlinear structural dynamical systems via element-wise stiffness Evaluation Procedure combined with hyper-reduction
Computational Mechanics, 2021Co-Authors: Jonggeon Lee, Jaehun Lee, Haeseong Cho, Euiyoung Kim, Maenghyo ChoAbstract:In nonlinear analysis, performing iterative inverse calculation and nonlinear system construction Procedures incurs expensive computational costs. This paper presents an element-wise stiffness Evaluation Procedure combined with hyper-reduction reduced-order modeling (HE-STEP ROM) method. The proposed approach constructs a non-intrusive reduced-order model based on an element-wise stiffness Evaluation Procedure (E-STEP) and hyper-reduction methods. Because the E-STEP evaluates nonlinear stiffness coefficients element-by-element using cubic polynomial, numerous number of polynomial variables are required. The number of variables directly affects the computational efficiency of the online and offline stages. Therefore, to enhance efficiency of the online/offline stages, the proposed method employs hyper-reduction method. By applying hyper-reduction, the full stiffness coefficients are approximated from the stiffness coefficients evaluated at a few sampling points. Subsequently, the number of polynomial equations and variables is prominently reduced, and the efficiency of the reduced system increases. The efficiency and accuracy of the proposed approach are validated via several structural dynamic problems with geometric and material nonlinearities.
Haeseong Cho - One of the best experts on this subject based on the ideXlab platform.
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Reduced-order modeling of nonlinear structural dynamical systems via element-wise stiffness Evaluation Procedure combined with hyper-reduction
Computational Mechanics, 2021Co-Authors: Jonggeon Lee, Jaehun Lee, Haeseong Cho, Euiyoung Kim, Maenghyo ChoAbstract:In nonlinear analysis, performing iterative inverse calculation and nonlinear system construction Procedures incurs expensive computational costs. This paper presents an element-wise stiffness Evaluation Procedure combined with hyper-reduction reduced-order modeling (HE-STEP ROM) method. The proposed approach constructs a non-intrusive reduced-order model based on an element-wise stiffness Evaluation Procedure (E-STEP) and hyper-reduction methods. Because the E-STEP evaluates nonlinear stiffness coefficients element-by-element using cubic polynomial, numerous number of polynomial variables are required. The number of variables directly affects the computational efficiency of the online and offline stages. Therefore, to enhance efficiency of the online/offline stages, the proposed method employs hyper-reduction method. By applying hyper-reduction, the full stiffness coefficients are approximated from the stiffness coefficients evaluated at a few sampling points. Subsequently, the number of polynomial equations and variables is prominently reduced, and the efficiency of the reduced system increases. The efficiency and accuracy of the proposed approach are validated via several structural dynamic problems with geometric and material nonlinearities.
