A novel strain field reconstruction method for test monitoring

For the static loading test in the aerospace field, conventional strain field reconstruction based on finite element analysis (FE-SFRM) is difficult to meet the accuracy requirements of test monitoring. A novel experiment strain field reconstruction method (EXP-SFRM) is proposed to improve the accuracy and monitoring effect of recon-structed field. Firstly, the coordinates of strain gauges are introduced to build the connections in space between discrete strain gauges and make it possible to check the accuracy of finite element analysis. Next, the real-time strains with high-precision coordinates are employed to reconstruct the strain field by radial basis function. A cantilever plate test and a large opening cylindrical shell (LOCS) test are performed to validate the high accuracy and good monitoring effect of EXP-SFRM. For the LOCS test, a maximum inward and outward bending criterion (MIOBC) is also proposed to determine the buckling regions. The results show that the average errors of EXP-SFRM are 2.8% (cantilever plate) and 17.4% (LOCS), which are 4.8% and 26.4% lower than these of FE-SFRM. Additionally, for LOCS, the risk regions predicted by EXP-SFRM are finally consistent with the real buckling regions, while these predicted by FE-SFRM are not. Compared with conventional FE-SFRM, the EXP-SFRM is proved to have high accuracy and good monitoring effect during test process.

Automated summary

A novel experiment strain field reconstruction method (EXP-SFRM) is proposed to improve the accuracy and monitoring effect of conventional strain field reconstruction based on finite element analysis. The method introduces the coordinates of strain gauges to establish connections between discrete strain gauges and finite element analysis. Experimental tests are conducted to validate the high accuracy and good monitoring effect of EXP-SFRM. Compared with conventional FE-SFRM, EXP-SFRM exhibits lower average errors and predicts the buckling regions more accurately.