Design Optimization of Spring of a Locking Nut using Design of Experiments

다국어 초록 (Multilingual Abstract)

The bolt and nut is a representative fastener used in a machine assembly. When a load is repetitively applied to the
bolt and nut assembly in the perpendicular direction of the bolt axis, the nut gradually loosens. To address this
problem, nuts of diverse structures and shapes have been developed. In this study, a loose-proof locking nut is
developed using a spring. The spring prevents the loosening of the nut by augmenting the axial load of the bolt.
Three dimensional finite element models for the bolt, nut, spring and vibration plate are generated, and the
loosening performance of the nut is analyzed using MSC/Marc, a commercial finite element analysis program.
With the optimization technique based on the design of experiments, the shape and material of the spring are
optimized. The optimal results are applied to the bolt and nut connection. The performance of the newly developed
locking nut with a spring is compared to that of the general nut and bolt connection without a spring and the
effectiveness of the locking nut is verified.

참고문헌 (Reference)

1 정성필, "제동 장치 최적 설계 모듈 개발" 한국자동차공학회 16 (16): 166-171, 2008

2 Lee, W. H, "study on the development of loose prevention bolts and nut" 529-530, 2007

3 Park, S, "Understanding of Design of Experiments" Minyoungsa 2005

4 Sakai, S, "Three-dimensional finite element analysis on tightening and loosening mechanism of bolted joints" 12 (12): 604-615, 2005

5 Taguchi, G, "Robust Engineering: Learn How to Boost Quality While Reducing Cost & Time to Market" McGraw-Hill 1999

6 Myers, R. H, "Response Surface Methodology: Process and Product Optimization Using Design of Experiments" John Wiley & Sons 1995

7 Ta-Kwan Woo, "Preventing Loose Bolts and Reducing the Number of Bolts Required in Plate Heat Exchangers" 한국정밀공학회 10 (10): 29-34, 2009

8 Vanderplaats, G. N, "Numerical Optimization Techniques for Engineering Design with Applications" McGraw-Hill 1984

9 Junker, G, "New criteria for self-loosening of fasteners under vibration" 78 : 314-335, 1969

10 Sakai, S, "Investigation of bolt loosening mechanisms: 1st report, On the bolts of transversely loaded joints" 21 : 1385-1390, 1978

11 Zhang, M, "Finite element modeling of selfloosening of bolted joints" 129 (129): 218-224, 2007

12 Sawa, T, "Experimental evaluation of screw thread loosening in bolted joint with some parts for preventing the loosening under transverse repeated loads" 2006

13 Sawa, T, "Analytical research on mechanism of bolt loosening due to lateral loads" 2005