This paper proposes a rigorous undrained solution for cylindrical cavity expansion problems in K_(0)-consolidated clays,adopting a simple non-associated and anisotropic model,SANICLAY.The cavity expansion theory is we...This paper proposes a rigorous undrained solution for cylindrical cavity expansion problems in K_(0)-consolidated clays,adopting a simple non-associated and anisotropic model,SANICLAY.The cavity expansion theory is well extended to consider non-associativity,K_(0)-consolidation and stress-induced anisotropy with combined rotational and distortional hardening of yield surface and plastic potential in the multiaxial stress space.The developed solution can be recovered for validation against the modified Cam-clay(MCC)solution by simply setting model constants,avoiding non-associativity and anisotropy.The source code is provided to facilitate the use for extensions.After investigating the effects of overconsolidation ratio on the cavity pressure curves,stress distributions,evolutions of anisotropic parameters and stress paths,the variations with three-dimensional(3D)evolutions of yield surface and plastic potential during undrained cavity expansion are shown for various K_(0)-consolidated clays.A parametric study on the model constants is presented to depict the influences on the stress distributions and paths,critical state surfaces and Lode’s angles at failure.The proposed solution also provides a general framework for formulating equations for undrained expansion of cylindrical cavities under an initial cross anisotropic condition using sophisticated anisotropic soil models.It serves as a precise benchmark for extensions of analytical solutions,numerical simulations of cavity expansion,and backcalculations of geotechnical problems.展开更多
核数据不确定性分析影响着反应堆安全,在反应堆堆芯物理计算过程中具有重要意义。利用SCALE6.1程序包中KENO模块建立反应堆模拟评估和验证基准BEAVRS(Benchmark for Evaluation and Validation of Reactor Simulations)第一循环热态零...核数据不确定性分析影响着反应堆安全,在反应堆堆芯物理计算过程中具有重要意义。利用SCALE6.1程序包中KENO模块建立反应堆模拟评估和验证基准BEAVRS(Benchmark for Evaluation and Validation of Reactor Simulations)第一循环热态零功率堆芯物理模型,采用TSUNAMI-3D模块开展k_(eff)的敏感性与不确定性分析,分析了不同燃料富集度、不同温度对k_(eff)敏感性与不确定性的影响。结果表明:核数据不确定性导致BEAVRS模型的k_(eff)总的不确定性为0.5016%;^(235)U的平均裂变中子数敏感性导致k_(eff)的敏感性系数最大(0.92658);对k_(eff)不确定性贡献最大的是238U(n,γ)反应截面,为0.29814%;在燃料富集度降低、温度上升时,238U(n,γ)反应截面不确定性会导致k_(eff)的不确定性增大。因此,在开展反应堆堆芯物理计算过程中,应重点关注238U(n,γ)反应截面信息。展开更多
Magnetic skyrmions,the topological spin textures firstly observed in chiral magnets,have aroused huge interest due to their emergent electromagnetism and potential applications in spintronics.Over the last decade,sign...Magnetic skyrmions,the topological spin textures firstly observed in chiral magnets,have aroused huge interest due to their emergent electromagnetism and potential applications in spintronics.Over the last decade,significant efforts have been devoted to skyrmion generation,stabilization,and dynamics.In most cases,the theoretical and experimental investigations have been performed in the materials where the skyrmions have a circular shape.As we know,magnetic anisotropy(K_(u))and Dzyaloshinskii-Moriya interaction(DMI)play key roles in the stabilization of the skyrmions in chiral magnets.Therefore,modifying the Kand DMI provide new degrees of freedom for studying the related physics and applications of skyrmions in addition to engineering their energetics and sizes.In this review,the latest progress on the study of the anisotropic deformation of magnetic skyrmions(i.e.,elliptical magnetic skyrmions)is summarized.The physical origins and important advantages of elliptical magnetic skyrmions are mainly focused on.This review gives an insight into the understanding of the physical mechanisms of elliptical magnetic skyrmion-hosting systems.展开更多
基金the funding support from National Natural Science Foundation of China (Grant Nos. 51908546 and 52178374)China Postdoctoral Science Foundation (Grant No. 2020T130699)
文摘This paper proposes a rigorous undrained solution for cylindrical cavity expansion problems in K_(0)-consolidated clays,adopting a simple non-associated and anisotropic model,SANICLAY.The cavity expansion theory is well extended to consider non-associativity,K_(0)-consolidation and stress-induced anisotropy with combined rotational and distortional hardening of yield surface and plastic potential in the multiaxial stress space.The developed solution can be recovered for validation against the modified Cam-clay(MCC)solution by simply setting model constants,avoiding non-associativity and anisotropy.The source code is provided to facilitate the use for extensions.After investigating the effects of overconsolidation ratio on the cavity pressure curves,stress distributions,evolutions of anisotropic parameters and stress paths,the variations with three-dimensional(3D)evolutions of yield surface and plastic potential during undrained cavity expansion are shown for various K_(0)-consolidated clays.A parametric study on the model constants is presented to depict the influences on the stress distributions and paths,critical state surfaces and Lode’s angles at failure.The proposed solution also provides a general framework for formulating equations for undrained expansion of cylindrical cavities under an initial cross anisotropic condition using sophisticated anisotropic soil models.It serves as a precise benchmark for extensions of analytical solutions,numerical simulations of cavity expansion,and backcalculations of geotechnical problems.
文摘核数据不确定性分析影响着反应堆安全,在反应堆堆芯物理计算过程中具有重要意义。利用SCALE6.1程序包中KENO模块建立反应堆模拟评估和验证基准BEAVRS(Benchmark for Evaluation and Validation of Reactor Simulations)第一循环热态零功率堆芯物理模型,采用TSUNAMI-3D模块开展k_(eff)的敏感性与不确定性分析,分析了不同燃料富集度、不同温度对k_(eff)敏感性与不确定性的影响。结果表明:核数据不确定性导致BEAVRS模型的k_(eff)总的不确定性为0.5016%;^(235)U的平均裂变中子数敏感性导致k_(eff)的敏感性系数最大(0.92658);对k_(eff)不确定性贡献最大的是238U(n,γ)反应截面,为0.29814%;在燃料富集度降低、温度上升时,238U(n,γ)反应截面不确定性会导致k_(eff)的不确定性增大。因此,在开展反应堆堆芯物理计算过程中,应重点关注238U(n,γ)反应截面信息。
基金financially supported by Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110553)Science Center of the National Science Foundation of China(No.52088101)+5 种基金Beijing Natural Science Foundation(No.Z190009)the National Natural Science Foundation of China(NSFC,Nos.11874409 and 11904056)K.C.Wong Education Foundation(No.GJTD-2019-14)China Postdoctoral Science Foundation(No.2020M670499)Guangzhou basic and applied basic research project(No.202102020053)the startup funding from Songshan Lake Materials Laboratory(No.Y1D1071S511)。
文摘Magnetic skyrmions,the topological spin textures firstly observed in chiral magnets,have aroused huge interest due to their emergent electromagnetism and potential applications in spintronics.Over the last decade,significant efforts have been devoted to skyrmion generation,stabilization,and dynamics.In most cases,the theoretical and experimental investigations have been performed in the materials where the skyrmions have a circular shape.As we know,magnetic anisotropy(K_(u))and Dzyaloshinskii-Moriya interaction(DMI)play key roles in the stabilization of the skyrmions in chiral magnets.Therefore,modifying the Kand DMI provide new degrees of freedom for studying the related physics and applications of skyrmions in addition to engineering their energetics and sizes.In this review,the latest progress on the study of the anisotropic deformation of magnetic skyrmions(i.e.,elliptical magnetic skyrmions)is summarized.The physical origins and important advantages of elliptical magnetic skyrmions are mainly focused on.This review gives an insight into the understanding of the physical mechanisms of elliptical magnetic skyrmion-hosting systems.
