دانلود رایگان مقاله مطالعه شکست چرخ بوت فرمان سرعت ترک خورده

Abstract

Failure of a cracked steering wheel is studied in this paper. Steering wheel, mounted on a speed boat, had cracks emanating from one of the fastener holes until final fracture occurred. Failure analysis, combining experimental and numerical techniques, was performed. Experimentally, fasteners torque moments were measured, visual inspection performed and material type determined (aluminum alloy AA 6061). Additionally, scanning electron microscopy examination was employed to characterize the microstructure of the fractured surface. Using finite element analysis, stress analysis of a cracked steering wheel was conducted. Stress intensities of uncracked and cracked steering wheel were compared to find out about stress concentration points. Possible causes of crack occurrence include excessive fastener torque moment, fretting between fastener and hole combined with poor machining that left marks that serve as potential crack initiation points. Obtained results are valuable for predicting fracture behavior of the cracked steering wheel and can be taken as a reference for design and exploitation process of such component.

6. Conclusion

Fracture behavior of a cracked speed boat steering wheel has been studied in this paper. During regular use cracks started emanating from one of the six fracture holes by which the wheel was attached to column. After final fracture, wheel was detached from boat and subjected to fracture analysis. Results, obtained by experimental and numerical approach, suggest greater care should be taken in machining and mounting the wheel in order to avoid initial damage to the surface that could serve as a point of crack initiation. Also, care should be taken when tightening the fasteners not to exceed the torque limits as the additional load can improve crack growth. This study gives insight into the fracture behavior of a cracked steering wheel and can be found useful in the design process, mounting or exploitation of such component.