Design And Simulation Analysis Of The Frangible Structure Of Airport Visual Navigation Aid Lights

In the modern comprehensive transportation system,air transportation,with its unique advantages of safety,speed,accessibility,and comfort,has not only established an independent industrial position,but also become a national strategic leading industry.With the increase in air traffic,flight safety has become a key concern for various countries.Designing fragile airport navigation lights can minimize aircraft losses after collisions.The research on the frangibility of airport navigation aids in China is still in its early stages.Currently,only a few manufacturers have conducted internal experimental research for the design of products,and a unified frangibility test and design program has not yet been formed.Therefore,the study of frangibility has important practical significance.Firstly,based on in-depth research and analysis of the functions and requirements of navigation aids,this thesis proposes a design scheme which is a dual segment rotatable and frangible navigation aid light,and provides the specific form and photometric parameters of the two parts frangible structure of the navigation aid light.The upper and lower sections of the structure have a frangible performance,and each section will collapse toword the heading direction of the aircraft after being impacted.If the upper segment is hit,it can break and fall down.Due to the action of connectors,it remaines connected to the substructure,and will not fall or fly out causing secondary damage to the aircraft.After the lower section of the frangible structure is hit,the special rivets on the flange plate will bear the impact load,by this way frangiblility works and the flange plate is more conducive to the sliding of the base and the column,which reduces the height of the overall structure of the navigation light to the maximum extent,so as to reduce the damage to the aircraft.The modal analysis of the overall structure of the navigation aid lamp was conducted using ANSYS Workbench,providing a theoretical basis for finding a reasonable impact location for stress analysis.Secondly,using the ANSYS Workbench Fluent and Workbench statics modules,the effects of 11 level wind on terrain A and B and the aircraft wake during takeoff of the Boeing 747-400 on the navigation lights were analyzed,on the grounds of fluid-structure interaction verifying whether the strength and stiffness of the navigation lights met the design requirements.Lastly,ANSYS Workbench was utilized to perform numeric simulations on two different impact positions(Part I Fragile structure,Part Ⅱ Fragile structure)of the navigation aid lamp using three different speeds(97 m/s,76 m/s,and 62.5 m/s)of the Boeing 747-400.The results show that the upper and lower sections of the frangible structure will fall down after impacting,and will not hinder the aircraft from continuing forward.Especially noteworthy is that the upper section of the structure will not fall,fly out,or result in consequential harm to the ground,surrounding buildings,and personnel.Furthermore,it satisfies the frangibility requirements for airport navigation aid lights.