基于iFEM和虚实结合的加筋板应变场构建研究

Strain field construction method of stiffened plate based on iFEM and virtual-real combination method

iFEM(inverse finite element method)是目前进行结构应变场构建最有前景的方法之一,其目的是在结构离散应变采集过程中,以最少的实际测点获取满足精度要求的结构应变场。在一些局部区域应变数据不易采集时,可尝试采用虚实结合的方式进行离散应变数据的采集。本文以船舶典型结构加筋板为例,根据实测数据,结合仿真模型,依据Xgboost的测点回归方法,基于iFEM技术依次计算实测、仿真和虚实结合三种方法的应变场重构精度,分析误差原因。通过预测,当47个物理测点时平均误差最低,为1.92%,以虚实结合路径输入15个点和21个点时结果与验证点的误差均小于3%,验证了虚实结合快速补充缺失数据的应变场重构的方法操作性强、准确度高。

At present,iFEM(inverse finite element method)is one of the most promising methods to con⁃struct a structural strain field.The purpose of this method is to obtain a structural strain field that meets the precision requirement with the least number of real measuring points in the process of discrete strain acquisi⁃tion.However,when it is difficult to collect strain data in some local areas,discrete strain data can be collect⁃ed by combining virtual and actual measuring points.In this paper,the stiffened plate of a typical ship struc⁃ture was taken as an example,according to the measured data,combined with the simulation model and the measurement point regression method of Xgboost,the strain field reconstruction accuracies of the three meth⁃ods of measurement,simulation and virtual and real combination were calculated based on the iFEM technol⁃ogy,and the causes of error were analyzed.The prediction results showed that the average error of 47 physi⁃cal measurement points was the lowest,which was 1.92%.When 15 points and 21 points were input through the virtual-real combination path,the errors between the results and the verification points were all less than 3%,which verified that the strain field reconstruction method of virtual-real combination with a quick sup⁃plement of the missing data has strong operability and high accuracy.