合理的参数估计是提高陆面模式模拟能力的关键,而其过高的维数极大地增加了合理估计的难度。参数的敏感性分析,旨在针对目标变量找出最敏感的参数,从而实现在有限计算机资源条件下,对参数进行合理估计。本文以Common Land Model(CoLM)...合理的参数估计是提高陆面模式模拟能力的关键,而其过高的维数极大地增加了合理估计的难度。参数的敏感性分析,旨在针对目标变量找出最敏感的参数,从而实现在有限计算机资源条件下,对参数进行合理估计。本文以Common Land Model(CoLM)为研究对象,利用Morris方法定性地从40个参数中筛选出影响土壤温度和土壤湿度的敏感参数,并通过Sobol′方法从敏感性顺序和各敏感参数的累积贡献率两个方面,对Morris方法分析结果进行验证。在此基础上,本研究还利用Sobol′方法对已筛选的参数做定量敏感性分析,最终确定参数的主效应、交互效应和总效应。研究结果表明,Morris方法可以基于少量样本实现复杂的陆面模式的参数筛选,而Sobol′方法的结果又从定量的角度描述了每个敏感参数对模型响应的影响程度,并且两种方法结论一致。展开更多
Considering the characteristics of sensitivity analysis in epistemic uncertain system,a new sensitivity analysis index based on Sobol' method was proposed. Then the index calculation method with single cycle Monte...Considering the characteristics of sensitivity analysis in epistemic uncertain system,a new sensitivity analysis index based on Sobol' method was proposed. Then the index calculation method with single cycle Monte-Carlo sampling was studied, and an application was developed. Numerical examples show that,the new method could solve the system sensitivity analysis problem with mixed aleotory and epistemic uncertainties. In this method,aleotory uncertain parameters could be sampled randomly according their distributions, and need not be translated to evidence bodies.Epistemic uncertain parameters were sampled randomly based on evidence theory. Therefore the loss of information in the sampling process was small,and the shortcomings of the existing methods were overcome.展开更多
In this paper, models of the global system of the Koyna dam have been created using ABAQUS software considering the dam-reservoir-fbundation interaction. Non coupled models and the coupled models were compared regardi...In this paper, models of the global system of the Koyna dam have been created using ABAQUS software considering the dam-reservoir-fbundation interaction. Non coupled models and the coupled models were compared regarding the horizontal displacement of the dam crest and the differential settlement of the dam base in clay foundation. Meta models were constructed and uncertainty quantification process was adopted by the support of Sobol's sensitivity in dices considering five un certain parameters by exploiting Box-Behnken experimental method. The non coupled models results determined overestimated predicted stability and damage detection in the dam. The rational effects of the reservoir height were very sensitive in the variation of the horizontal displacement of the dam crest with a small interaction effect with the beta viscous damping coefficient of the clay fbundation. The modulus of elasticity of the clay foundation was the decisive parameter regarding the variation of the differential settlement of the dam base. The XFEM approach has been used for damage detection in relation with both minimum and maximum values of each uncertain parameter. Finally the effects of clay and rock foundations were determined regarding the resistance against the propagation of cracks in the dam, where the rock fbundation was the best.展开更多
文摘合理的参数估计是提高陆面模式模拟能力的关键,而其过高的维数极大地增加了合理估计的难度。参数的敏感性分析,旨在针对目标变量找出最敏感的参数,从而实现在有限计算机资源条件下,对参数进行合理估计。本文以Common Land Model(CoLM)为研究对象,利用Morris方法定性地从40个参数中筛选出影响土壤温度和土壤湿度的敏感参数,并通过Sobol′方法从敏感性顺序和各敏感参数的累积贡献率两个方面,对Morris方法分析结果进行验证。在此基础上,本研究还利用Sobol′方法对已筛选的参数做定量敏感性分析,最终确定参数的主效应、交互效应和总效应。研究结果表明,Morris方法可以基于少量样本实现复杂的陆面模式的参数筛选,而Sobol′方法的结果又从定量的角度描述了每个敏感参数对模型响应的影响程度,并且两种方法结论一致。
基金Basic Research Project of Equipment Development Department,China(No.2015zk1.2)
文摘Considering the characteristics of sensitivity analysis in epistemic uncertain system,a new sensitivity analysis index based on Sobol' method was proposed. Then the index calculation method with single cycle Monte-Carlo sampling was studied, and an application was developed. Numerical examples show that,the new method could solve the system sensitivity analysis problem with mixed aleotory and epistemic uncertainties. In this method,aleotory uncertain parameters could be sampled randomly according their distributions, and need not be translated to evidence bodies.Epistemic uncertain parameters were sampled randomly based on evidence theory. Therefore the loss of information in the sampling process was small,and the shortcomings of the existing methods were overcome.
文摘In this paper, models of the global system of the Koyna dam have been created using ABAQUS software considering the dam-reservoir-fbundation interaction. Non coupled models and the coupled models were compared regarding the horizontal displacement of the dam crest and the differential settlement of the dam base in clay foundation. Meta models were constructed and uncertainty quantification process was adopted by the support of Sobol's sensitivity in dices considering five un certain parameters by exploiting Box-Behnken experimental method. The non coupled models results determined overestimated predicted stability and damage detection in the dam. The rational effects of the reservoir height were very sensitive in the variation of the horizontal displacement of the dam crest with a small interaction effect with the beta viscous damping coefficient of the clay fbundation. The modulus of elasticity of the clay foundation was the decisive parameter regarding the variation of the differential settlement of the dam base. The XFEM approach has been used for damage detection in relation with both minimum and maximum values of each uncertain parameter. Finally the effects of clay and rock foundations were determined regarding the resistance against the propagation of cracks in the dam, where the rock fbundation was the best.
