Rapid analysis method of helicopter fuselage bullet damage based on bullet penetration theory

Helicopter fuselage has a complex shape and structure. Numerical simulation analysis of helicopter fuselage bullet damage based on the finite element method is computationally intensive and takes a long time. It is difficult to quickly analyze and evaluate helicopter fuselage bullet damage in a complex multi-bomb environment. To this end, the bullet penetration theory and the bullet impact calculation model were coupled to establish a rapid analysis method for helicopter fuselage bullet damage, and the accuracy of the rapid analysis method was verified by comparing with test results and finite element numerical simulation results. Then the helicopter fuselage bomb coordinates, residual speed and fuselage damage area of the multi-bomb strike were studied. Research shows that the residual velocity calculated by the rapid analysis method is consistent with the test results; compared with the finite element numerical simulation of bullet damage, the maximum error of the projectile residual velocity calculated by the rapid analysis method is 4.7%, and the maximum error of the fuselage damage area is 9.56%, and the calculation time is reduced 92.1%. Computational efficiency is significantly improved. As the incident angle of the projectile increases, the residual velocity decreases and the damage area increases; when the incident angle of the projectile is too large, the projectile cannot penetrate the surface of the fuselage, causing sink-like sliding damage, causing a larger area of damage.