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A New Explicit Algorithm for Bi-Phasic Mixture Flow in MIM 认领 引用 被引量：3
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作者 柳葆生 Barriere Th Gelin J.C 《Journal of Southwest Jiaotong University(English Edition)》 2002年第2期152-160,共9页
Metal injection moulding (MIM) is a new technology to manufacture small intricate parts in large quantity. Numerical simulation plays an important role in its development. To predict the specific segregation effect in... Metal injection moulding (MIM) is a new technology to manufacture small intricate parts in large quantity. Numerical simulation plays an important role in its development. To predict the specific segregation effect in MIM injection, mixture theory is adopted to model the injection flow by a bi-phasic model. This model conducts to the solution of two-coupled Stokes equations. It is an extremely computational consuming solution in the scope of the traditional algorithms, which induce a serious challenge to cost-effectivity of the MIM simulation. Referred to some methods proposed by Lewis in mono-phasic simulation and the implicit algorithms in MIM simulation, a new explicit algorithm is proposed and realized to perform efficiently this type of bi-phasic flow. Numerically this algorithm is devised to perform the simulation in a fully uncoupled manner except for a global solution of the pressure field in each time step. The physical coupling is taken into account in a sequential pattern by fractional steps. 展开更多
关键词 metal injection moulding simulation explicit algorithm bi-phasic flow
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Nonlinear evaluations of unconditionally stable explicit algorithms 认领 引用 被引量：1
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作者 Shuenn-Yih Chang 《Earthquake Engineering and Engineering Vibration》 SCIE EI 2009年第3期329-340,共12页
Two explicit integration algorithms with unconditional stability for linear elastic systems have been successfully developed for pseudodynamic testing. Their numerical properties in the solution of a linear elastic sy... Two explicit integration algorithms with unconditional stability for linear elastic systems have been successfully developed for pseudodynamic testing. Their numerical properties in the solution of a linear elastic system have been well explored and their applications to the pseudodynamic testing of a nonlinear system have been shown to be feasible. However, their numerical properties in the solution of a nonlinear system are not apparent. Therefore, the performance of both algorithms for use in the solution of a nonlinear system has been analytically evaluated after introducing an instantaneous degree of nonlinearity. The two algorithms have roughly the same accuracy for a small value of the product of the natural frequency and step size. Meanwhile, the first algorithm is unconditionally stable when the instantaneous degree of nonlinearity is less than or equal to 1, and it becomes conditionally stable when it is greater than 1. The second algorithm is conditionally stable as the instantaneous degree of nonlinearity is less than 1/9, and becomes unstable when it is greater than 1. It can have unconditional stability for the range between 1/9 and 1. Based on these evaluations, it was concluded that the first algorithm is superior to the second one. Also, both algorithms were found to require commensurate computational efforts, which are much less than needed for the Newmark explicit method in general structural dynamic problems. 展开更多
关键词 explicit integration algorithms unconditional stability pseudodynamic algorithm nonlinear system instantaneous degree of nonlinearity
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Stability of an explicit time-integration algorithm for hybrid tests, considering stiffness hardening behavior 认领 引用 被引量：4
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作者 Wang Tao Zhou Huimeng +1 位作者 Zhang Xipeng Ran Tianran 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2018年第3期595-606,共12页
An explicit unconditionally stable algorithm for hybrid tests,which is developed from the traditional HHT-α algorithm,is proposed.The unconditional stability is first proven by the spectral radius method for a linear... An explicit unconditionally stable algorithm for hybrid tests,which is developed from the traditional HHT-α algorithm,is proposed.The unconditional stability is first proven by the spectral radius method for a linear system.If the value of α is selected within [-0.5,0],then the algorithm is shown to be unconditionally stable.Next,the root locus method for a discrete dynamic system is applied to analyze the stability of a nonlinear system.The results show that the proposed method is conditionally stable for dynamic systems with stiffness hardening.To improve the stability of the proposed method,the structure stiffness is then identified and updated.Both numerical and pseudo-dynamic tests on a structure with the collision effect prove that the stiffness updating method can effectively improve stability. 展开更多
关键词 explicit integration algorithm unconditional stability HHT-α algorithm stiffness identification root locus method
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Study on Contact Algorithm of Dynamic Explicit FEM for Sheet Forming Simulation 认领 引用
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作者 Zhang Hai-ming Dong Xiang-huai Li Zhi-gang 《Wuhan University Journal of Natural Sciences》 EI CAS 2001年第3期704-708,共5页
Based on existing algorithms, a newly developed contact search algorithm is proposed. The new algorithm consists of global search, local searching, local tracking and penetration calculation processes. It requires no ... Based on existing algorithms, a newly developed contact search algorithm is proposed. The new algorithm consists of global search, local searching, local tracking and penetration calculation processes. It requires no iteration steps. It can deal with not only general tool surfaces with vertical walls, but also tool surfaces meshed with elements having very poor aspect ratios. It is demonstrated that the FE code employing this new contact search algorithm becomes more reliable, efficient and accurate for sheet metal forming simulation than conventional ones. 展开更多
关键词 contact algorithm dynamic explicit FEM sheet metal forming
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Investigation into the Computational Costs of Using Genetic Algorithm and Simulated Annealing for the Optimization of Explicit Friction Factor Models 认领 引用
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作者 Sunday Boladale Alabi Abasiyake Uku Ekpenyong 《Journal of Materials Science and Chemical Engineering》 2022年第12期1-9,共9页
Research reports show that the accuracies of many explicit friction factor models, having different levels of accuracies and complexities, have been improved using genetic algorithm (GA), a global optimization approac... Research reports show that the accuracies of many explicit friction factor models, having different levels of accuracies and complexities, have been improved using genetic algorithm (GA), a global optimization approach. However, the computational cost associated with the use of GA has yet to be discussed. In this study, the parameters of sixteen explicit models for the estimation of friction factor in the turbulent flow regime were optimized using two popular global search methods namely genetic algorithm (GA) and simulated annealing (SA). Based on 1000 interval values of Reynolds number (Re) in the range of and 100 interval values of relative roughness () in the range of , corresponding friction factor (f) data were obtained by solving Colebrook-White equation using Microsoft Excel spreadsheet. These data were then used to modify the parameters of the selected explicit models. Although both GA and SA led to either moderate or significant improvements in the accuracies of the existing friction factor models, SA outperforms the GA. Moreover, the SA requires far less computational time than the GA to complete the corresponding optimization process. It can therefore be concluded that SA is a better global optimizer than GA in the process of finding an improved explicit friction factor model as an alternative to the implicit Colebrook-White equation in the turbulent flow regime. 展开更多
关键词 Genetic Algorithm Simulated Annealing Global Optimization Explicit Friction Factor Computational Cost
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A MESH-FREE ALGORITHM FOR DYNAMIC IMPACT ANALYSIS OF HYPERELASTICITY 认领 引用 被引量：2
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作者 De’an Hu Zhanhua Sun +1 位作者 Chao Liang Xu Han 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2013年第4期362-372,共11页
A mesh-free method based on local Petrov-Galerkin formulation is presented to solve dynamic impact problems of hyperelastic material.In the present method,a simple Heaviside test function is chosen for simplifying dom... A mesh-free method based on local Petrov-Galerkin formulation is presented to solve dynamic impact problems of hyperelastic material.In the present method,a simple Heaviside test function is chosen for simplifying domain integrals.Trial function is constructed by using a radial basis function （RBF） coupled with a polynomial basis function,in which the shape function possesses the kronecker delta function property.So,additional treatment is not required for imposing essential boundary conditions.Governing equations of impact problems are established and solved node by node by using an explicit time integration algorithm in a local domain,which is very similar to that of the collocation method except that numerical integration can be implemented over local domain in the present method.Numerical results for several examples show that the present method performs well in dealing with the dynamic impact problem of hyperelastic material. 展开更多
关键词 mesh-free method dynamic impact problem hyperelasticity explicit algorithm
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混序全显BOR-FDTD算法的CPML/PML实现 认领 引用
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作者 朱大伟 陈海林 +2 位作者 沈忠文 贾秀玲 李镇 《计算物理》 CSCD 北大核心 2026年第3期357-366,共10页
为改进时域有限差分(FDTD)算法在电磁波传播效率方面的不足,构建混序FDTD算法的卷积/完全匹配层(CPML/PML)实现,并应用至旋转对称(BOR)柱形结构。对BOR–FDTD算法的电磁场方程进行时域至频域的转换,进而对其频域方程进行坐标伸缩变换,... 为改进时域有限差分(FDTD)算法在电磁波传播效率方面的不足,构建混序FDTD算法的卷积/完全匹配层(CPML/PML)实现,并应用至旋转对称(BOR)柱形结构。对BOR–FDTD算法的电磁场方程进行时域至频域的转换,进而对其频域方程进行坐标伸缩变换,并添加CPML/PML辅助函数后再次转换至时域。获取系数矩阵,并引入微扰项,得到两个子时间步下BOR–FDTD算法CPML/PML实现的新形式。通过数学变换,推导出混序全显BOR–FDTD算法的CPML/PML实现方程。算例证明,所提算法的CPML/PML实现与BOR–FDTD算法相比,在内存消耗近乎一致的情况下,最佳可提高效率约64%。所提算法在CPML/PML实现下呈现良好的电磁波吸收性能,均不超过–60 dB。 展开更多
关键词 时域有限差分算法 旋转对称体 混序全显 系数矩阵 卷积/完全匹配层 轴上特殊处理
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耦合非线性波动方程的高效保结构算法 认领 引用
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作者 余姣 付亚运 赵艳敏 《许昌学院学报》 CAS 2026年第2期1-6,共6页
提出了一种用于构建耦合非线性波动方程显式保结构格式的新方法.为此,首先在保持方程固有结构的前提下,将其转化为典则哈密顿系统;随后,基于系统的哈密顿形式给出了一种全新的时间离散方法,进而得到了保能量的数值格式.所得格式为显式格... 提出了一种用于构建耦合非线性波动方程显式保结构格式的新方法.为此,首先在保持方程固有结构的前提下,将其转化为典则哈密顿系统;随后,基于系统的哈密顿形式给出了一种全新的时间离散方法,进而得到了保能量的数值格式.所得格式为显式格式,具有很高的计算效率.最后,通过数值算例验证了所提方法在长时间数值模拟中的守恒性及有效性. 展开更多
关键词 耦合非线性波动方程 哈密顿系统 保结构算法 显式格式
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Comparison and assessment of time integration algorithms for nonlinear vibration systems 认领 引用
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作者 YANG Chao YANG Bao-zhu +1 位作者 ZHU Tao XIAO Shou-ne 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第5期1090-1097,共8页
A corrected explicit method of double time steps(CEMDTS) was introduced to accurately simulate nonlinear vibration problems in engineering. The CEMDTS, the leapfrog central difference method, the Newmark method, the g... A corrected explicit method of double time steps(CEMDTS) was introduced to accurately simulate nonlinear vibration problems in engineering. The CEMDTS, the leapfrog central difference method, the Newmark method, the generalized-a method and the precise integration method were implemented in typical nonlinear examples for the purpose of comparison. Both conservative and non-conservative systems were examined. The results show that it isn't unconditionally stable for the precise integration method, the Newmark method and the generalized-a method in nonlinear systems. The stable interval of the three methods is less than that of the CEMDTS. When a small time step(?t≤Tmin/20) is employed, the precise integration method is endowed with the highest accuracy while the CEMDTS possesses the smallest computation effort. However, the CEMDTS becomes the most accurate one when the time step is large(?t≥0.3Tmin) or the system is strongly nonlinear. Therefore, the CEMDTS is more applicable to the nonlinear vibration systems. 展开更多
关键词 nonlinear vibration conservative system explicit algorithm accuracy
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全景劳动控制:平台经济中青年劳动者的算法与数据之困 认领 引用
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作者 卢瑶 《山东青年政治学院学报》 2026年第4期46-55,共10页
随着数字技术深度嵌入生产生活,平台经济逐渐形成以算法和数据为核心的“全景劳动控制”。这一结构对青年劳动者的控制包含两条相互关联的路径:其一是对劳动过程的显性劳动控制,即以算法管理为中介,资本对青年的劳动节奏、绩效与行为进... 随着数字技术深度嵌入生产生活,平台经济逐渐形成以算法和数据为核心的“全景劳动控制”。这一结构对青年劳动者的控制包含两条相互关联的路径:其一是对劳动过程的显性劳动控制,即以算法管理为中介,资本对青年的劳动节奏、绩效与行为进行实时干预与自动化规训;其二是对劳动成果的隐性劳动控制,即通过数据劳动的无酬化与去劳动化认定,将青年用户的日常活动转化为被无偿占有的价值来源。从算法管理的运行逻辑与数据劳动的生成机制入手,可分析显性劳动控制如何重构青年劳动者的劳动过程,隐性劳动控制如何在“有酬-无酬”结构中实现价值转化。同时,基于对隐性劳动控制生成背后的价值创造机制与数据私有化问题的讨论,发现技术进步在现有制度条件下并不必然改善青年的劳动处境。由此,未来有必要以青年劳动者主体性与时间支配为规范尺度,对平台经济中的劳动控制结构进行批判性反思。 展开更多
关键词 平台经济 青年劳动者 算法管理 数据劳动 显性劳动控制 隐性劳动控制
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A NEW EXPLICIT SIMULATION FOR MOULD FILLING WITH HIGH VISCOUS FEEDSTOCK 认领 引用
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作者 Cheng Zhiqiang Barriere Thierry +1 位作者 Liu Baosheng Gelin Jean Claude 《Acta Mechanica Solida Sinica》 SCIE 2004年第4期347-352,共6页
In the simulation of the metal injection moulding (MIM), the behaviours of feedstock are much di?erent from which of the polymer injection. It is a mixture of the metallic powder in high concentration and some plastic... In the simulation of the metal injection moulding (MIM), the behaviours of feedstock are much di?erent from which of the polymer injection. It is a mixture of the metallic powder in high concentration and some plastic binder. The advance in simulation of the mould ?lling with such high viscous feedstock is featured by the development of a fully explicit vectorial algorithm. On the basis of previous explicit software realized by the authors, the new algorithm avoids the global solution for pressure ?elds and the use of MINI elements to improve its e?ciency. Except for the operations at element level, neither global solution nor the construction of global matrix is required in simulation. A special strategy is used to regulate the incompressibility condition in ?lled domain at each time step. In case of the MIM problems, this method provides a fast way to simulate the ?lling processes. The computational cost is about linearly proportional to the degree of freedom number. Moreover, this vectorial algorithm can be easily parallelized for high performance computation with multi-clusters. The comparison of numerical results with previous simulations on 3D cases proves the validity and e?ciency of new algorithm. 展开更多
关键词 mould filling high viscosity explicit simulation vectorial algorithm
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Extensions of nonlinear error propagation analysis for explicit pseudodynamic testing 认领 引用
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作者 Shuenn-Yih Chang 《Earthquake Engineering and Engineering Vibration》 SCIE EI 2009年第1期77-86,共10页
Two important extensions of a technique to perform a nonlinear error propagation analysis for an explicit pseudodynamic algorithm （Chang, 2003） are presented. One extends the stability study from a given time step t... Two important extensions of a technique to perform a nonlinear error propagation analysis for an explicit pseudodynamic algorithm （Chang, 2003） are presented. One extends the stability study from a given time step to a complete step-by-step integration procedure. It is analytically proven that ensuring stability conditions in each time step leads to a stable computation of the entire step-by-step integration procedure. The other extension shows that the nonlinear error propagation results, which are derived for a nonlinear single degree of freedom （SDOF） system, can be applied to a nonlinear multiple degree of freedom （MDOF） system. This application is dependent upon the determination of the natural frequencies of the system in each time step, since all the numerical properties and error propagation properties in the time step are closely related to these frequencies. The results are derived from the step degree of nonlinearity. An instantaneous degree of nonlinearity is introduced to replace the step degree of nonlinearity and is shown to be easier to use in practice. The extensions can be also applied to the results derived from a SDOF system based on the instantaneous degree of nonlinearity, and hence a time step might be appropriately chosen to perform a pseudodynamic test prior to testing. 展开更多
关键词 nonlinear error propagation explicit pseudodynamic algorithm stability condition step-by-step integration procedure step degree of nonlinearity
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基于AMGA的仪表板管梁内高压成形加载路径优化 认领 引用 被引量：2
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作者 郑再象 姚梓豪 +3 位作者 潘正健 徐晶 谭慧 王峰 《锻压技术》 CAS CSCD 北大核心 2025年第10期111-117,共7页
针对解析法、试验法和数值模拟方法在设计仪表板管梁内高压成形过程加载路径时存在的局限性,给出了一种新的加载路径匹配优化方法,即将基于存档的微遗传算法与基于动态显式算法的有限元软件集成,通过修改内压加载曲线和轴向进给曲线上... 针对解析法、试验法和数值模拟方法在设计仪表板管梁内高压成形过程加载路径时存在的局限性,给出了一种新的加载路径匹配优化方法,即将基于存档的微遗传算法与基于动态显式算法的有限元软件集成,通过修改内压加载曲线和轴向进给曲线上所设置的关键控制节点的数值来匹配设计加载路径,在更大的解空间内实现对加载路径的自动寻优,并通过实例证明了该优化方法的可行性。优化结果表明,通过该方法获取的加载路径比通过人工寻优获取的加载路径更优,管坯壁厚分布更加均匀,轴向进给量更少。此外,该方法在单次迭代下可针对多目标优化下的不同方向获得多个Pareto最优解,为管件内高压成形工艺参数选择提供了更多方案。 展开更多
关键词 内高压成形 仪表板管梁 加载路径 微遗传算法 动态显式算法
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基于罚函数法的大变形冲击碰撞问题显式健壮格式 认领 引用 被引量：1
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作者 初东阳 戎宇飞 +3 位作者 周章涛 伍星星 汪俊 王海坤 《爆炸与冲击》 EI CAS CSCD 北大核心 2025年第3期154-167,共14页
为了提高基于罚函数法的显式有限元对大变形接触-碰撞问题仿真的精确性和健壮性,基于前增量位移中心差分方法,发展了一种新的大变形接触非侵入算法。将动力方程求解步分解为不考虑接触的预估步和考虑接触的修正步,在当前时刻,采用罚函... 为了提高基于罚函数法的显式有限元对大变形接触-碰撞问题仿真的精确性和健壮性,基于前增量位移中心差分方法,发展了一种新的大变形接触非侵入算法。将动力方程求解步分解为不考虑接触的预估步和考虑接触的修正步,在当前时刻,采用罚函数法施加接触惩罚力,使其满足非侵入条件,从而提高显式接触计算的精确性;在仅能获得下一时刻位移的情况下,为了精确计算下一时刻的大变形内力,基于任意参考构型大变形理论,将动力学方程内力项映射到已知的参考构型求解,避免使用相关物理量的中间构型近似值,从而降低由大变形计算引入的数值误差。更严格的几何非线性算法以及接触算法可有效抑制实体间的非物理穿透和大变形碰撞过程中的单元畸变,提高计算程序的健壮性。对典型碰撞及侵彻算例进行仿真,并与商业软件的结果进行对比,验证了所发展的大变形接触-碰撞显式算法的正确性,并证明了在高速大变形碰撞仿真方面,当前接触-碰撞显式算法比基于蛙跳格式中心差分和罚函数法的经典接触-碰撞算法更加健壮。 展开更多
关键词 接触-碰撞 显式有限元方法 接触算法 几何大变形 罚函数法
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一种具有可控数值阻尼的无条件稳定半显式积分算法 认领 引用
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作者 傅博 张付泰 +1 位作者 张清凯 陈瑾 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2025年第2期113-121,共9页
结构模型经过有限元方法空间离散化处理之后,可能引入虚假的高频分量,这部分高频分量会对结构的动力响应求解带来不利影响。为此,需要引入算法的数值阻尼有效地抑制这部分虚假的高频分量。使用半显式算法格式,通过匹配隐式ρ∞-Bath... 结构模型经过有限元方法空间离散化处理之后,可能引入虚假的高频分量,这部分高频分量会对结构的动力响应求解带来不利影响。为此,需要引入算法的数值阻尼有效地抑制这部分虚假的高频分量。使用半显式算法格式,通过匹配隐式ρ∞-Bathe算法放大矩阵的特征方程系数,提出一种具有可控数值阻尼的无条件稳定半显式积分算法,记为NSE(New Semi-Explicit)-ρ∞算法,新算法通过两个自由参数ρ∞和γ控制算法的数值阻尼,并且无需对结构运动方程进行加权处理。对新算法的稳定性、精度、周期延长和振幅衰减等数值特性进行分析,结果表明,新算法对于线弹性体系和非线性刚度软化体系均为无条件稳定。通过具有代表性的数值算例,将新算法与两种具有可控数值阻尼的无条件稳定显式积分算法进行对比,证明新算法能够更加有效地抑制虚假高频分量。 展开更多
关键词 积分算法 显式 稳定 数值阻尼 结构动力学
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面向大型结构实时计算的显卡加速显式非线性振型叠加法 认领 引用
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作者 王贞 黄健君 +2 位作者 武文斌 吴斌 徐小洋 《地震工程与工程振动》 CSCD 北大核心 2025年第5期154-163,共10页
该文针对具有局部耗能非线性的大型桥梁结构的实时计算问题,提出了一种图形处理器(graphics processing unit,GPU)加速的显式非线性振型叠加法(explicit nonlinear mode superposition method,ENMS)。该方法视非线性反力为外荷载,采用... 该文针对具有局部耗能非线性的大型桥梁结构的实时计算问题,提出了一种图形处理器(graphics processing unit,GPU)加速的显式非线性振型叠加法(explicit nonlinear mode superposition method,ENMS)。该方法视非线性反力为外荷载,采用振型叠加法对单积分步线性运动方程进行解耦,并采用显式逐步积分法求解,避免了运动方程迭代求解,利用了振型叠加法的快速计算优势,大幅提升计算效率。针对方程已经解耦的特征,利用GPU加速计算,进一步提升计算效率。某大跨度斜拉桥数值仿真研究表明:对于存在局部非线性的大型多自由度结构,该方法可利用Midas Civil导出的参数方便地进行动力响应求解,结果精度高;对于黏滞阻尼器的指数阻尼Maxwell模型,二分法能够准确求解阻尼力,较好地解决非线性阻尼器建模问题;GPU加速可显著提升显式非线性振型叠加法计算效率。 展开更多
关键词 大型桥梁结构 局部非线性 非线性振型叠加法 显式积分算法 GPU加速计算 实时计算分析
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基于改进四阶辛-谱元的三维宽频带地震动数值模拟方法 认领 引用
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作者 巴振宁 寇阔 +1 位作者 赵靖轩 张郁山 《力学学报》 EI CAS CSCD 北大核心 2025年第9期2192-2208,共17页
基于确定性物理模型的震源-传播-场地全过程地震动模拟是目前地震工程的重要研究方向,然而随着模拟频率的不断提高,对目前数值模拟方法中显式时间积分算法的计算精度和效率提出了双重挑战.文章提出了一种融合四阶PEFRL(position extende... 基于确定性物理模型的震源-传播-场地全过程地震动模拟是目前地震工程的重要研究方向,然而随着模拟频率的不断提高,对目前数值模拟方法中显式时间积分算法的计算精度和效率提出了双重挑战.文章提出了一种融合四阶PEFRL(position extended Forest-Ruth like)辛积分与谱元法(spectral element method,SEM)的三维高效数值模拟方法,旨在突破现有SEM中在宽频带模拟中精度、稳定性和效率上的瓶颈问题.其中,PEFRL算法通过优化传统Forest-Ruth算法的步进策略,将加速度求解次数由5次降至4次,并采用位移-速度交替更新机制,能够有限降低内存需求与计算成本.将提出的方法针对均匀、多层与盆地半空间模型,分别与二阶的Newmark和四阶的Runge-Kutta时间积分算法计算的结果进行对比.数值实验表明,随着模型复杂和模拟频率的上升,改进后的PEFRL-SEM方法精度提升效果愈加显著.针对半空间模型、多层介质模型与盆地模型模拟的时程结果相位相对误差分别降低16.7%,20.7%和21.3%,能量相对误差分别降低20.6%,22.3%和24.7%;针对10 Hz半空间模型模拟工况,相位相对误差和能量相对误差分别降低55.4%和36.3%,计算效率较LDDRK算法最高可提升约33%.进一步,将该方法成功应用于1994年北岭MW6.7地震的三维宽频带(0~10 Hz)地震动模拟,模拟结果与观测记录在振幅及频谱特征上均表现出良好一致性.该方法有效解决了宽频带地震动场模拟的稳定性与计算效率的问题,显著提升了宽频带强地震动场模拟在地震工程领域的实用性,为区域地震危险性分析与工程抗震评估提供了一种高精度、高效率宽频带地震动模拟方法. 展开更多
关键词 谱元法 辛方法 宽频带模拟 确定性地震动模拟 显式时间积分算法
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面向显式算法基于Python语言人工边界与地震力可视化建模程序开发与验证 认领 引用 被引量：3
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作者 陈志超 柳国环 费琦翔 《计算力学学报》 CAS CSCD 北大核心 2025年第3期386-394,共9页
成功自主开发了基于Python语言面向显式算法的可视化接口程序,与大型商业软件ABAQUS精准对接,可高效完成三维黏弹性人工边界建模与等效地震力自动施加。阐明了面向显式算法接口程序的意义及其与传统外挂式及隐式程序的本质区别,在此基... 成功自主开发了基于Python语言面向显式算法的可视化接口程序,与大型商业软件ABAQUS精准对接,可高效完成三维黏弹性人工边界建模与等效地震力自动施加。阐明了面向显式算法接口程序的意义及其与传统外挂式及隐式程序的本质区别,在此基础上提出两点式跟随行动线(轴向)弹簧-阻尼元件完全等效的方法,解决了显式算法下接地弹簧-阻尼元件失效的固有问题,验证了其可行性和准确性,为后续程序开发奠定理论基础;推导了程序直接使用的P,SV及SH波垂直入射时等效节点力的时间迟滞效应解析解公式,公式推导过程物理意义清晰且理论完备;阐明了程序的底层逻辑、开发流程及关键函数;最后,以自由场P,SV及SH波同时垂直入射经典算例,验证了建模的黏弹性人工边界对散射波的吸收作用,与理论解吻合。本文成果可用于边界-土-结构相互作用的科学研究与工程实践。 展开更多
关键词 黏弹性人工边界 地震动输入 显式算法 Python语言 ABAQUS二次开发
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融合显式Newmark-β法与迭代正则化的动载荷识别 认领 引用
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作者 李鸿秋 姜金辉 陈国平 《振动工程学报》 EI CSCD 北大核心 2025年第11期2600-2608,共9页
本文基于显式Newmark-β法建立了适用于连续系统的动载荷时域识别方法,突破了传统Newmark-β法只适用于离散系统的局限。针对Newmark-β法在动载荷识别问题中出现的不适定性,本文提出了一种混合LSQR正则化修正方法。该方法在传统LSQR算... 本文基于显式Newmark-β法建立了适用于连续系统的动载荷时域识别方法,突破了传统Newmark-β法只适用于离散系统的局限。针对Newmark-β法在动载荷识别问题中出现的不适定性,本文提出了一种混合LSQR正则化修正方法。该方法在传统LSQR算法中融入了Tikhonov正则化思想,抑制求解过程中的数值震荡,引入一种基于响应残差的动态修正机制,通过对比计算响应与实测响应之间的残差,对载荷估计进行修正,该方法将Tikhonov正则化的稳定优势与迭代算法的适应性有效结合,显著改善了动载荷识别过程中的不适定性。通过典型工况的数值仿真,在不同噪声水平与多种载荷条件下验证了所提方法的鲁棒性与识别精度,性能明显优于传统正则化算法。随机载荷识别试验的研究结果表明,本文所提的混合LSQR正则化修正方法具备较强的抗噪能力与优异的识别精度。 展开更多
关键词 动载荷识别 显式Newmark-β法 模态空间 混合LSQR修正算法 连续系统
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车联网中基于位置信息映射和相关性评估的进化多任务优化算法 认领 引用 被引量：4
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作者 沈俊杰 彭江 +1 位作者 郭坤银 刘凯 《电子学报》 EI CAS CSCD 北大核心 2025年第5期1661-1676,共16页
随着车联网(Internet of Vehicles,IoV)和智能交通系统的兴起,计算成本的增加和问题规模的扩大使得实时应用的实现变得极具挑战性,同时也为车载边缘计算(Vehicular Edge Computing,VEC)带来了大量亟待并行求解的组合优化问题.这些复杂... 随着车联网(Internet of Vehicles,IoV)和智能交通系统的兴起,计算成本的增加和问题规模的扩大使得实时应用的实现变得极具挑战性,同时也为车载边缘计算(Vehicular Edge Computing,VEC)带来了大量亟待并行求解的组合优化问题.这些复杂的实际问题往往具有非凸性、不可微性,甚至存在黑盒目标与约束条件,可能会超出传统数学方法的解决范围.进化多任务优化(Evolutionary Multi-Task Optimization,EMTO)作为一种新兴的多任务优化范式,通过充分利用任务间的潜在相关性,能够有效地实现多个独立优化任务的并行求解.本文设计了一种IoV显式EMTO框架,结合IoV任务的特点,深入挖掘任务间隐含的关联性,并提出了一种基于车辆位置映射和相关性评估的IoV EMTO算法.针对IoV环境下的多任务优化问题,本文对车-路数据路由(Data Routing,DR)、车-路服务迁移(Ser-vice Migration,SM)、车-车消息传输(Message Transmission,MT)和车-车任务卸载(Task Offloading,TO)四个问题进行联合优化,目标是在限定时间内最大化各个任务的交付率.进一步地,为了在任务相关性未知的情况下提升相关任务间的知识迁移效率,本文在算法中设计并引入了基于任务相关性评估的迁移机制.具体而言,通过计算链路间最长公共子序列来计算链路的相似度,针对不同的相关性分布情况设计了三种迁移策略,以确保算法在不同场景下的知识迁移能力.最后,本文通过实验验证和性能评估,验证了所提框架和算法的有效性,与其他的EMTO算法相比,本文所提算法在各优化问题上的收敛速度更快,种群间知识迁移后的求解效果更好,展现出良好的性能. 展开更多
关键词 车载边缘计算(VEC) 进化算法 多任务优化 显式知识转移 任务相关性评估
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