Tuan Le Viet, a graduate student in the Department of Aircraft Strength of the Aircraft faculty, NSTU NATI, has developed a computational model showing how hail impacts affect the composite parts of an aircraft.
To date, the percentage of composite materials in airliners can reach up to 80%. This is due to their strength compared will steel analogs, high corrosion resistance, reliability, and durability. However, even the most durable material can undergo deformation associated with shock loads. If the plane enters a hail cloud, there is a high probability that it will be damaged. For most composite structures, high-speed loads caused by hail impacts are critical.
As the author of the project notes, damage to structures is almost impossible to detect visually because the inner layers of composite materials, including binders, can deform. Thus, it turns out that externally, the wing of the aircraft may be whole, but it is no longer able to carry a certain load. There is a potential danger in the further operation of the aircraft. Therefore, it is important to understand the types of damage an aircraft can receive when exposed to hail in order to determine their real level.
"We have developed a computational model that describes the behavior of the hailstone itself when it hits the composite panel: the hailstone breaks, while we immediately consider the type of deformation inside the panel. We simulated a series of impacts with different particle sizes and velocities on the multilayer composite panels. Further development will be to simulate the impact on high-risk areas (wing tip) or on the entire surface of the wing. Previously, studies on the effects of a series of hail impacts on composite panels, as well as on the assessment of residual strength after impact, have not been conducted. We will conduct further experiments with numerical models to determine the damage inside the panel and calculate the residual strength," said Tuan Le Viet.
This model is applicable to the activities of aviation industry enterprises (scientific institutes, design bureaus, etc.). It can be used in the design of aircraft structures and in the testing and strength studies of composite materials.