The numerical accuracy of drop process simulation and collision response for drones is primarily determined by the finite element modeling method and simplified method of drone airframe structure. For light and small drones exhibiting diverse shapes and configurations, mixed materials and structures, deformation and complex destruction behaviors, the way of developing a reasonable and easily achieved high-precision simplified modeling method by ensuring the calculation accuracy and saving the calculation cost has aroused increasing concern in impact dynamics simulation. In the present study, the full-size modeling and simplified modeling methods that are specific to different components of a relatively popular light and small drone were analyzed in an LS-DYNA software environment. First, a full-size high-precision model of the drone was built, and the model accuracy was verified by performing the drop tests at the component level as well as the whole machine level. Subsequently, based on the full-size high-precision model, the property characteristics of the main components of the light and small drone and their common simplification methods were classified, a series of simplified modeling methods for different components were developed, several single simplified models and combined simplified models were built, and a method to assess the calculation error of the peak impact load in the simplified models was proposed. Lastly, by comparing and analyzing the calculation accuracy of various simplified models, the high-precision simplified modeling strategy was formulated, and the suggestions were proposed for the impact dynamics simulation of the light and small drone falling. Given the analysis of the calculation scale and solution time of the simplified model, the high-precision simplified modeling method developed here is capable of noticeably reducing the modeling difficulty, the solution scale and the calculation time while ensuring the calculation accuracy. Moreover, it shows promising applications in several fields (e.g., structure design, strength analysis and impact process simulation of drone).

For unmanned aerial vehicles (UAVs), their motor and camera are rigid components that are most likely causing damage in the event of a collision. Therefore, in the research of UAVs collision simulation, establishing accurate motor and camera FE models is the key step. Kinetic material tests were conducted for 7075 aluminum alloy, and an accurate material model was obtained. A test of motor and camera strike on plates was developed, and the dynamic response of the plates was obtained to verify the numerical method of UAV motor and camera strike on plates. Based on these, accurate FE models of motor and camera were established. In addition, the motor and camera were divided into element models with different sizes, and the influence of element size on calculation accuracy and efficiency was investigated. It is indicated that when the average size of the motor grid is less than 1.25 mm and the average size of the camera grid is less than 1 mm, a good balance could be achieved between calculation accuracy and calculation efficiency. Through comprehensive consideration, a 1.25 mm and a 1 mm mesh model were selected for the motor and the camera, respectively, to establish their finite element model which was then employed in the simulation of motor and camera strike on plates. The simulation results showed that the strain-time curve peak of the aluminum plate impacted by the motor had an error of 9.5% with the experimental result and that by the camera had an error of 9.7% with the experimental result. At the same time, the influences of speed and collision angle were investigated. It is indicated that the greater collision angle of the motor, the smaller collision angle of the camera, and the greater impact speed of both cause greater damage to the aluminum plate. The FE modelling method and collision simulation method of motor and camera proposed in this paper can greatly save the resources for testing the UAV performance through the practical structural strength test, especially for light and small UAVs.