考虑预测误差的模型内插与外推

Interpolation and Extrapolation Considering the Model Prediction Error

对结构进行评估时,常需要利用模型的内插与外推结果,且模型的不确定性也是需要考虑的一个重要因素。针对模型参数空间的内插外推问题,基于确定性计算模型并联合多次试验结果,计算得到预测误差的不确定性;接着对预测误差的均值与标准差进行函数拟合;并且考虑函数拟合带来的不确定性。通过双层抽样分析得到预测误差的置信区间,再叠加上预测点确定性计算结果,进而得到预测结果的置信区间。最后通过不同拧紧力矩下某根部柔性悬臂梁的内插与外推应用,检验了该方法的有效性。

The interpolation and extrapolation resultare usually needed to evaluate the structural design. Also, the uncertainty of the model ian importanfactoto consider. The interpolation and extrapolation problem in the parametespace iresearched. Firstly the uncertain prediction errorare obtained by combining the deterministianalysiresultand the multi-tesresults. Then the mean and standard deviation are fitted by the uncertain predic- tion errors, the uncertainty of function fitting iconsidered also. Thirdly the erroconfidence interval of prediction position icalculated by the fitting function and double level sample method. Lastly the confidence interval of pre- diction resuliobtained by adding the certain calculation resulathe prediction position. The efficiency of the method ivalidated by the flexible roocantilevesubjected to differenpreload.