参数不确定性估计的随机响应面模型修正方法

摘要

正确估计实际工程结构中参数和响应不确定性的大小，能有效提高分析结果的可靠性。首先基于概率配点法和回归分析建立随机响应面模型，以表述不确定性参数与响应间复杂的隐式函数关系，快速估计响应的统计特征值；然后提出一种两阶段修正策略，分步修正参数的均值和标准差，以简化随机修正过程、提高修正效率；最后基于一组55块钢板的实测频率均值和标准差，估计钢板厚度和材料参数的统计特征值，验证方法的可行性和可靠性。%Accurate uncertainty estimation for parameters and responses of real‐world structures may improve the reliability of analysis results .In this study ,by using the probabilistic collocation method and regression analysis ,stochastic response sur‐face models are firstly constructed for expressing the complex implicit relationship between the uncertain parameters and re‐sponses of a structure .Then the statistical features of the responses can be quickly estimated using the constructed models . Meanwhile ,a two‐stage updating strategy is employed which separately updates the parameter means and standard deviations in the interest of problem simplification and improvement in updating efficiency .Lastly ,fifty‐five nominally identical steel plates were tested in the laboratory .The means and standard deviations of the measured natural frequencies under a free‐free boundary condition have been adopted to estimate the statistical features of the plate thicknesses and material properties .By this means ,the feasibility and reliability of the proposed method has been validated .