This paper proposes a variational binary level set method for shape and topology optimization of structural.First,a topology optimization problem is presented based on the level set method and an algorithm based on bi...This paper proposes a variational binary level set method for shape and topology optimization of structural.First,a topology optimization problem is presented based on the level set method and an algorithm based on binary level set method is proposed to solve such problem.Considering the difficulties of coordination between the various parameters and efficient implementation of the proposed method,we present a fast algorithm by reducing several parameters to only one parameter,which would substantially reduce the complexity of computation and make it easily and quickly to get the optimal solution.The algorithm we constructed does not need to re-initialize and can produce many new holes automatically.Furthermore,the fast algorithm allows us to avoid the update of Lagrange multiplier and easily deal with constraints,such as piecewise constant,volume and length of the interfaces.Finally,we show several optimum design examples to confirm the validity and efficiency of our method.展开更多
In this paper,operator splitting scheme for dynamic reservoir characterization by binary level set method is employed.For this problem,the absolute permeability of the two-phase porous medium flow can be simulated by ...In this paper,operator splitting scheme for dynamic reservoir characterization by binary level set method is employed.For this problem,the absolute permeability of the two-phase porous medium flow can be simulated by the constrained augmented Lagrangian optimization method with well data and seismic time-lapse data.By transforming the constrained optimization problem in an unconstrained one,the saddle point problem can be solved by Uzawas algorithms with operator splitting scheme,which is based on the essence of binary level set method.Both the simple and complicated numerical examples demonstrate that the given algorithms are stable and efficient and the absolute permeability can be satisfactorily recovered.展开更多
基金the support of Zhejiang Provincial Natural Science Foundation of China(No.LQ12A01012)Key Project of the Major Research Plan of NSFC(No.91130004)the Major Projects on Control and Rectification of Water Body Pollution of China(No.2009ZX07424-001).
文摘This paper proposes a variational binary level set method for shape and topology optimization of structural.First,a topology optimization problem is presented based on the level set method and an algorithm based on binary level set method is proposed to solve such problem.Considering the difficulties of coordination between the various parameters and efficient implementation of the proposed method,we present a fast algorithm by reducing several parameters to only one parameter,which would substantially reduce the complexity of computation and make it easily and quickly to get the optimal solution.The algorithm we constructed does not need to re-initialize and can produce many new holes automatically.Furthermore,the fast algorithm allows us to avoid the update of Lagrange multiplier and easily deal with constraints,such as piecewise constant,volume and length of the interfaces.Finally,we show several optimum design examples to confirm the validity and efficiency of our method.
基金The author thanks to his supervisor Prof.Lin Qun(Institute of Computational Mathematics,Chinese Academy of Sciences),Prof.Tai Xuecheng,Prof.S.I.Aanonsen(CIPR,University of Bergen)for useful suggestions.This work is also supported by China NSFC(NO.11101084)and NSFC(NO.11101081).
文摘In this paper,operator splitting scheme for dynamic reservoir characterization by binary level set method is employed.For this problem,the absolute permeability of the two-phase porous medium flow can be simulated by the constrained augmented Lagrangian optimization method with well data and seismic time-lapse data.By transforming the constrained optimization problem in an unconstrained one,the saddle point problem can be solved by Uzawas algorithms with operator splitting scheme,which is based on the essence of binary level set method.Both the simple and complicated numerical examples demonstrate that the given algorithms are stable and efficient and the absolute permeability can be satisfactorily recovered.
