Dynamic Load Identification Method During Missile Flight

Abstract

The external load of the missile during the flight can cause the structure vibration,which may trigger the onset of combustion instability. To better understand the combustion instability,it is important to predict the external load. A dynamic load recognition method based on the neural network was proposed. The missile model was designed,and the finite element modal analysis and modal experiment were carried out,and the typical modal vibration-frequency was extracted. The rationality of the finite element method was verified. The neural network is trained by enough sample data from the simulation results,so that the neural network can recognize typical loads. The relevant experimental modal was manufactured,and the ground test system was set up. The typical load was first identified. The relative error can reach 1.21%,which verifies the accuracy of the trained neural network and the feasibility of the test system. Subsequently,the random load was identified. The results show that the relative error of identifying random dynamic loads is less than 1.82% by the proposed method,and the load identification method has good recognition ability. It is of great significance for the prediction of rocket structural design and engine combustion instability.