Researchers have achieved remarkable control over material properties by designing novel architectures,particularly for tuning Poisson’s ratio.Despite abundant existing approaches,significant design space remains une...Researchers have achieved remarkable control over material properties by designing novel architectures,particularly for tuning Poisson’s ratio.Despite abundant existing approaches,significant design space remains unexplored.This work presents two metamaterial designs exhibiting directionally dependent zero Poisson’s ratio,i.e.,one-way zero Poisson’s ratio.In other loading directions,these metamaterials display positive or negative Poisson’s ratio.This selectivity stems from a mode switching mechanism between“unbuckling”and“buckling”of well-designed members within the metamaterials.Theoretical analysis reveals the conditions governing this mode switch,numerical simulation and experiments confirm the one-way Poisson’s effect.Furthermore,the high stiffness contrast within these buckling-prone members yields a pronounced asymmetry in equivalent moduli of the metamaterials under tension and compression,breaking the inherent symmetry of the elastic matrix of conventional materials.This asymmetry is then exploited to design metamaterial beams with asymmetric bending stiffness.Our findings and the design strategy presented here pave the way for developing advanced metamaterials with previously unattainable and unexpected Poisson’s ratios.展开更多
Negative Poisson’s ratio materials and structures exhibit lateral expansion under tensile loading,demonstrating significant mechanical advantages over conventional materials.This study systematically investigated thr...Negative Poisson’s ratio materials and structures exhibit lateral expansion under tensile loading,demonstrating significant mechanical advantages over conventional materials.This study systematically investigated three typical two-dimensional negative Poisson’s ratio metamaterial structures(Concave honeycomb,Anti-chiral,and Anti-chiral concave honeycomb hybrid structures)through both experimental tests and numerical analysis.The test specimens were fabricated using selective laser melting(SLM)additive manufacturing technology,and the experimental test was conducted with the use of a DIC strain measurement system.The numerical studies were performed considering both static tensile loading and dynamic impact loading with different strain rates.The deformation behaviors,failure process,negative Poisson’s ratio effects,and energy absorption capacity of the three different metamaterial structures are systematically investigated,and the associated mechanical mechanisms are thoroughly revealed.Results and findings of this work could provide valuable guidance for the engineering design and application of negative Poisson’s ratio metamaterials and structures.展开更多
This paper investigates nonlinear Landau damping in the 3D Vlasov-Poisson(VP)system.We study the asymptotic stability of the Poisson equilibriumμ(v)=1/π2(1+|v|2)2 under small perturbations.Building on the f...This paper investigates nonlinear Landau damping in the 3D Vlasov-Poisson(VP)system.We study the asymptotic stability of the Poisson equilibriumμ(v)=1/π2(1+|v|2)2 under small perturbations.Building on the foundational work of Ionescu,Pausader,Wang and Widmayer[28],we provide a streamlined proof of nonlinear Landau damping for the 3D unscreened VP system.Our analysis leverages sharp decay estimates,novel decomposition techniques to demonstrate the stabilization of the particle distribution and the decay of electric field.These results reveal the free transport-like behavior for the perturbed densityρ(t,x),and enhance the understanding of Landau damping in an unconfined setting near stable equilibria.展开更多
To solve the Poisson equation it is usually possible to discretize it into solving the corresponding linear system Ax=b.Variational quantum algorithms(VQAs)for the discretized Poisson equation have been studied before...To solve the Poisson equation it is usually possible to discretize it into solving the corresponding linear system Ax=b.Variational quantum algorithms(VQAs)for the discretized Poisson equation have been studied before.We present a VQA based on the banded Toeplitz systems for solving the Poisson equation with respect to the structural features of matrix A.In detail,we decompose the matrices A and A2into a linear combination of the corresponding banded Toeplitz matrix and sparse matrices with only a few non-zero elements.For the one-dimensional Poisson equation with different boundary conditions and the d-dimensional Poisson equation with Dirichlet boundary conditions,the number of decomposition terms is less than that reported in[Phys.Rev.A 2023108,032418].Based on the decomposition of the matrix,we design quantum circuits that efficiently evaluate the cost function.Additionally,numerical simulation verifies the feasibility of the proposed algorithm.Finally,the VQAs for linear systems of equations and matrix-vector multiplications with the K-banded Toeplitz matrix TnKare given,where TnK∈Rn×nand K∈O(ploylogn).展开更多
基金supported by the National Natural Science Foundation of China(Grants Nos.11932002 and 11902004).
摘要Researchers have achieved remarkable control over material properties by designing novel architectures,particularly for tuning Poisson’s ratio.Despite abundant existing approaches,significant design space remains unexplored.This work presents two metamaterial designs exhibiting directionally dependent zero Poisson’s ratio,i.e.,one-way zero Poisson’s ratio.In other loading directions,these metamaterials display positive or negative Poisson’s ratio.This selectivity stems from a mode switching mechanism between“unbuckling”and“buckling”of well-designed members within the metamaterials.Theoretical analysis reveals the conditions governing this mode switch,numerical simulation and experiments confirm the one-way Poisson’s effect.Furthermore,the high stiffness contrast within these buckling-prone members yields a pronounced asymmetry in equivalent moduli of the metamaterials under tension and compression,breaking the inherent symmetry of the elastic matrix of conventional materials.This asymmetry is then exploited to design metamaterial beams with asymmetric bending stiffness.Our findings and the design strategy presented here pave the way for developing advanced metamaterials with previously unattainable and unexpected Poisson’s ratios.
基金supported by the National Natural Science Foundation of China(No.12472136)Innovation Fund of Marine Defense Technology Innovation Center(No.25GFC-JJ16-3608).
摘要Negative Poisson’s ratio materials and structures exhibit lateral expansion under tensile loading,demonstrating significant mechanical advantages over conventional materials.This study systematically investigated three typical two-dimensional negative Poisson’s ratio metamaterial structures(Concave honeycomb,Anti-chiral,and Anti-chiral concave honeycomb hybrid structures)through both experimental tests and numerical analysis.The test specimens were fabricated using selective laser melting(SLM)additive manufacturing technology,and the experimental test was conducted with the use of a DIC strain measurement system.The numerical studies were performed considering both static tensile loading and dynamic impact loading with different strain rates.The deformation behaviors,failure process,negative Poisson’s ratio effects,and energy absorption capacity of the three different metamaterial structures are systematically investigated,and the associated mechanical mechanisms are thoroughly revealed.Results and findings of this work could provide valuable guidance for the engineering design and application of negative Poisson’s ratio metamaterials and structures.
基金supported by the Academy of Mathematics and Systems ScienceChinese Academy of Sciences startup fund+3 种基金the National Natural Science Foundation of China(12050410257,12288201)the National Key R&D Program of China(2021YFA1000800)partially supported by the National Key R&D Program of China(2021YFA1001500)partially supported by the NSF of China(12288101)。
摘要This paper investigates nonlinear Landau damping in the 3D Vlasov-Poisson(VP)system.We study the asymptotic stability of the Poisson equilibriumμ(v)=1/π2(1+|v|2)2 under small perturbations.Building on the foundational work of Ionescu,Pausader,Wang and Widmayer[28],we provide a streamlined proof of nonlinear Landau damping for the 3D unscreened VP system.Our analysis leverages sharp decay estimates,novel decomposition techniques to demonstrate the stabilization of the particle distribution and the decay of electric field.These results reveal the free transport-like behavior for the perturbed densityρ(t,x),and enhance the understanding of Landau damping in an unconfined setting near stable equilibria.
基金supported by the Shandong Provincial Natural Science Foundation for Quantum Science under Grant No.ZR2021LLZ002the Fundamental Research Funds for the Central Universities under Grant No.22CX03005A。
摘要To solve the Poisson equation it is usually possible to discretize it into solving the corresponding linear system Ax=b.Variational quantum algorithms(VQAs)for the discretized Poisson equation have been studied before.We present a VQA based on the banded Toeplitz systems for solving the Poisson equation with respect to the structural features of matrix A.In detail,we decompose the matrices A and A2into a linear combination of the corresponding banded Toeplitz matrix and sparse matrices with only a few non-zero elements.For the one-dimensional Poisson equation with different boundary conditions and the d-dimensional Poisson equation with Dirichlet boundary conditions,the number of decomposition terms is less than that reported in[Phys.Rev.A 2023108,032418].Based on the decomposition of the matrix,we design quantum circuits that efficiently evaluate the cost function.Additionally,numerical simulation verifies the feasibility of the proposed algorithm.Finally,the VQAs for linear systems of equations and matrix-vector multiplications with the K-banded Toeplitz matrix TnKare given,where TnK∈Rn×nand K∈O(ploylogn).