Analysis and optimization of strain measurement accuracy factor based on response surface method
The strain gauge is a critical sensor for diagnosing the health state of structural members,different strain gauges have different measurement accuracy.In order to study the conditions required for the strain gage to achieve higher measurement accuracy,the structural parameters of the sensitive gate of the strain gage and the ambient temperature were optimized.Firstly,the finite element calculation method was used to analyze the effects of sensitive grid length,aspect ratio and temperature on the measurement accuracy.Secondly,design-expert was used to establish a response surface model with measurement accuracy.The evaluation function method was used to optimize the response surface model to obtain the optimal parameter combination.Finally,the optimization was verified by the tensile and compression test of lattice members.The results of the study show that,there is an intermediate optimal value for the aspect ratio of the sensitive gate.The measurement accuracy does not improve with the increase of the length of the sensitive gate.25℃is the best ambient temperature for measurement.The optimal parameter combination obtained by the evaluation function method is used to optimize the response surface model,that is,L=4 mm,H=2 mm,T=25℃,and the measured accuracy of the strain gauge is significantly improved by 3.760%compared with that before optimization.Optimizing the response surface of the measured accuracy of the established strain gauge can significantly reduce the measurement error caused by the superposition effect of the studied factors on the strain gage.The research method provides an effective basis for the design and selection of strain gages.
strain gaugessensitive barriersmeasurement accuracydesign-expertresponse surface analysisevaluation function method