Temperature correction method for load measurement of aircraft composite structures

In view of the serious influence of temperature on load measurement results of aircraft composite structures, the influence mechanism of temperature on load measurement of aircraft structure was analyzed, and a temperature correction model including the relative response coefficient and thermal output of the strain bridge is established, and the general relation models of relative response coefficient and thermal output with structural temperature are given respectively. These relation models are verified by the temperature test and the temperature-load combined test of composite laminate coupons and the wing box test component. The findings indicate that, when the adhesive's temperature characteristics are met, the relationship between the thermal output and the structural temperature change is a cubic polynomial with zero intercept, and the reciprocal of the relative response coefficient is a power function of the dimensionless structure temperature. By using this technique, the flight measurement results of an aircraft's composite wing structure load can be corrected. The maximum relative change of the pressure center following modification is 30.68%, which greatly increases load measurement accuracy and yields trustworthy data for aircraft flight load verification.