直升机铝合金机身弹伤形态快速预测方法OA

For the rapid prediction and repair requirements of helicopter combat damage morphologies,a database for aluminum alloy body structures subjected to conical-cup-shaped armor-piercing bullets was established based on the Johnson-Cook constitutive model and impact finite element models.A double elliptic function model was developed to describe non-symmetric damage characteristics,incorporating key parameters such as bullet caliber,velocity,and incident angle to establish a relationship function for non-symmetric damage halves.A rapid prediction method for combat damage morphologies was proposed and compared against finite element numerical simulations,support vec-tor machine mode optimized by genetic algorithm models(GA-SVR mode),and experimental results.Subsequently,investigate the effects of projectile caliber,impact velocity,and incidence angle on wound ballistics morphology.The results demonstrate good agreement with experimental measurements,achieving maximum errors of 12.04%in width and 7.03%in length.Compared to finite element numerical simulations and the GA-SVR model,the rapid prediction method achieved MAPE(Mean Absolute Percentage Error)values of 2.87%,4.32%,and 0.62%for the left semi-length,right semi-length,and width of the projectile hole,respectively,while the comparative methods yielded 2.92%,2.67%,and 0.64%respectively.The MAE(Mean Absolute Error)for eccentricity was 0.554 and 0.35 re-spectively.The computational accuracy of the rapid prediction method is comparable to both finite element numerical method and the GA-SVR model.However,the computation time was reduced by approximately 88%and 97.7%re-spectively,demonstrating significantly improved computational efficiency.Compared to bullet caliber and velocity,inci-dent angle has a greater impact on combat damage morphologies.The relationship between the incident angle and the left and right halves of perforation diameter is described by a two-term exponential function,while its relationship with offset distance is given by a three-term polynomial equation.