Numerical and experimental modeling for bird and hail impacts on aircraft structure

Abstract

Aircraft bird-strike events are very common and dangerous. Hailstone impacts represent another threat for aircraft structures. As part of the certification process, an aircraft must demonstrate the ability to land safely after impact with a foreign object at normal flight operating speeds. Since experimental studies can be cost prohibitive, validated numerical impact simulation seems to be a viable alternative. Modelling of these soft body impacts still represents a challenge, involving modelling of both the target and the projectile. Here the smooth particle hydrodynamics method (SPH), which has been used successfully in ballistic applications involving bird strike scenarios, is extended to hail impact. The paper thus presents the meshless SPH numerical method as a novel modeling approach. The method is applied to model bird and hail impacts which are problems that traditional FEM based modeling methods typically struggle to solve because of involved mesh distortion problems. The numerical results are then evaluated by comparing with the data collected during recent experimental tests. The data acquisition methods are also described and evaluated for applications where the short duration of the impact presents a challenge. The accuracy of the numerical results allows us to conclude that the models developed can be used in the certification and/or design process of moving (aircraft) and stationary (wind turbines) composite structures subject to bird and hail impact.

Numerical Simulation on Rigid Foreign Object Exclusion in the Turboprop Engine Intake System With a Bypass Duct

“…Kim et al [10] presented a description of experimental investigations, numerical simulations, and the formulation of a method for predicting hail ice impact damage initiation, and in this method, he first built the hail model with DYNA3D code. Lavoie et al [11] developed the meshless SPH numerical method to model bird and hail impact, and without the involved mesh distortion problems in traditional FEM-based modeling methods, the new model can be more efficient. The team of Li [12]- [14] from Northwestern Polytechnical University of China systematically studied the hail and bird impact on the aircraft and engine.…”

Microwave Nondestructive Testing of Galvanic Corrosion and Impact Damage in Carbon Fiber Reinforced Polymer Composites

“…A brief review of the SPH method is provided in this sub-section for the sake of completeness and better understanding of our simulations. The SPH method can be considered as a finely meshed structure with solid elements where the elements themselves are discarded and only the nodes are kept [33]. The connectivity between the nodes only depends on the proximity of the neighboring nodes, called particles.…”

“…Under compression and at high strain rates, ice material begins to behave in a more brittle manner with a more linear stress-strain curve and decrease in post-yield deformation [46]. Thus, it can be generally assumed that the behavior of hail is brittle upon impact [33].…”

Soft impacts on aerospace structures

“…The SPH method is deemed to be the most efficient for this type of problem [176]. References [53], [146], [165], [166], [174], [177], [178], [179], [180], use it to model hailstones.…”