基于模态重分析技术,提出一种适合全局有限元模型(global finite element model, GFEM)的突风动响应高效计算方法。针对模型局部结构质量或刚度的细微变化,进行增量建模,充分利用现有构型结果,避免了传统分析中重复计算的步骤。对于质...基于模态重分析技术,提出一种适合全局有限元模型(global finite element model, GFEM)的突风动响应高效计算方法。针对模型局部结构质量或刚度的细微变化,进行增量建模,充分利用现有构型结果,避免了传统分析中重复计算的步骤。对于质量阵的变化,以已有构型模态向量为初始向量,通过迭代分析进行特征值求解,针对刚度阵的微小变化,特别引入Sherman-Morrison-Woodbury公式,实现刚度逆矩阵的增量分析,从而克服了大规模GFEM模型的特征值求解效率低的问题,最终建立了一套适合于工程应用的GFEM突风高效动响应分析方法。采用GTA模型进行了突风分析算法的验证,在此基础上,基于某模型机翼,对模态重分析算法在突风动响应分析中的应用进行了研究。结果表明,通过LU分解可避免保存稠密形式的刚度逆矩阵,通过合理的松弛因子和收敛阈值,可有效提升计算效率。展开更多
This paper presents a two-phase genetic algorithm (TPGA) based on the multi- parent genetic algorithm (MPGA). Through analysis we find MPGA will lead the population' s evol vement to diversity or convergence accor...This paper presents a two-phase genetic algorithm (TPGA) based on the multi- parent genetic algorithm (MPGA). Through analysis we find MPGA will lead the population' s evol vement to diversity or convergence according to the population size and the crossover size, so we make it run in different forms during the global and local optimization phases and then forms TPGA. The experiment results show that TPGA is very efficient for the optimization of low-dimension multi-modal functions, usually we can obtain all the global optimal solutions.展开更多
For some large-scale engineering structures in operating conditions, modal param- eters estimation must base itself on response-only data. This problem has received a considerable amount of attention in the past few y...For some large-scale engineering structures in operating conditions, modal param- eters estimation must base itself on response-only data. This problem has received a considerable amount of attention in the past few years. It is well known that the cross-correlation function between the measured responses is a sum of complex exponential functions of the same form as the impulse response function of the original system. So this paper presents a time-domain operating modal identifcation global scheme and a frequency-domain scheme from output-only by cou- pling the cross-correlation function with conventional modal parameter estimation. The outlined techniques are applied to an airplane model to estimate modal parameters from response-only data.展开更多
为分析和验证斐波那契树优化算法(Fibonacci tree optimization algorithm,FTO)求解多峰函数全局最优解的算法性能,对算法的可达性问题进行研究.本文基于斐波那契法构造一个斐波那契树结构,在搜索空间中进行全局、局部交替搜索,不易陷...为分析和验证斐波那契树优化算法(Fibonacci tree optimization algorithm,FTO)求解多峰函数全局最优解的算法性能,对算法的可达性问题进行研究.本文基于斐波那契法构造一个斐波那契树结构,在搜索空间中进行全局、局部交替搜索,不易陷入局部最优解.对斐波那契树优化算法基于该结构的可达性进行分析和证明.通过跟踪算法求解过程中坐标点的累积分布仿真实验和到达率的对比实验,分析和验证了算法求解多峰函数全局最优解的可达性.展开更多
文摘基于模态重分析技术,提出一种适合全局有限元模型(global finite element model, GFEM)的突风动响应高效计算方法。针对模型局部结构质量或刚度的细微变化,进行增量建模,充分利用现有构型结果,避免了传统分析中重复计算的步骤。对于质量阵的变化,以已有构型模态向量为初始向量,通过迭代分析进行特征值求解,针对刚度阵的微小变化,特别引入Sherman-Morrison-Woodbury公式,实现刚度逆矩阵的增量分析,从而克服了大规模GFEM模型的特征值求解效率低的问题,最终建立了一套适合于工程应用的GFEM突风高效动响应分析方法。采用GTA模型进行了突风分析算法的验证,在此基础上,基于某模型机翼,对模态重分析算法在突风动响应分析中的应用进行了研究。结果表明,通过LU分解可避免保存稠密形式的刚度逆矩阵,通过合理的松弛因子和收敛阈值,可有效提升计算效率。
基金Supported by the National Natural Science Foundation of China (70071042,60073043,60133010)
文摘This paper presents a two-phase genetic algorithm (TPGA) based on the multi- parent genetic algorithm (MPGA). Through analysis we find MPGA will lead the population' s evol vement to diversity or convergence according to the population size and the crossover size, so we make it run in different forms during the global and local optimization phases and then forms TPGA. The experiment results show that TPGA is very efficient for the optimization of low-dimension multi-modal functions, usually we can obtain all the global optimal solutions.
基金Project supported by the National Natural Science Foundation of China(No.50205012),Aeronautics Foundation(No.01152059)and Civil Aviation Foundation(No.1007-272001).
文摘For some large-scale engineering structures in operating conditions, modal param- eters estimation must base itself on response-only data. This problem has received a considerable amount of attention in the past few years. It is well known that the cross-correlation function between the measured responses is a sum of complex exponential functions of the same form as the impulse response function of the original system. So this paper presents a time-domain operating modal identifcation global scheme and a frequency-domain scheme from output-only by cou- pling the cross-correlation function with conventional modal parameter estimation. The outlined techniques are applied to an airplane model to estimate modal parameters from response-only data.
文摘为分析和验证斐波那契树优化算法(Fibonacci tree optimization algorithm,FTO)求解多峰函数全局最优解的算法性能,对算法的可达性问题进行研究.本文基于斐波那契法构造一个斐波那契树结构,在搜索空间中进行全局、局部交替搜索,不易陷入局部最优解.对斐波那契树优化算法基于该结构的可达性进行分析和证明.通过跟踪算法求解过程中坐标点的累积分布仿真实验和到达率的对比实验,分析和验证了算法求解多峰函数全局最优解的可达性.
