A novel bird strike model incorporating soft and skeletal tissues for impact damage of aircraft engine blades

This study presents a novel, biologically realistic pigeon model considering soft and skeletal tissues to enhance the assessment of impact damage processes on aircraft engine blades. The biologically realistic pigeon model incorporating bones, muscles, and visceral organs was employed using computed tomography scanning. The Johnson-Cook model was employed to describe the dynamic mechanical behavior of skeletal tissues, while fluid dynamics was utilized to model the soft tissues, thus establishing a bird strike finite element model. The model was validated through Wilbeck bird strike testing by comparing and analyzing the impact pressure against traditional bird models. This validation process enhanced the model's accuracy and demonstrated its effectiveness in simulating real bird strikes. The validated model was employed to investigate impact damage of TC4 titanium alloy fan blades, considering three bird body orientations and three impact locations. At the blade tip region, the highest equivalent stress (1,324 MPa) and axial displacement (38.3 mm) were observed, indicating greater damage when impacts occur at the tip region. Analysis of bird body impact orientation angles (0°, 45°, and 90°) revealed that damage is more pronounced at 90°. Bird fragment mass and size distributions under various impact conditions showed that longer fragments (>45 mm) were present under 0° bird body orientation, characterized by less severe blade damage, potentially posing a greater risk of secondary damage upon entering the aircraft engine compartment.