Bending Collapse of Thin Walled Energy Absorber and Presenting Numerical Simplified Model

علوم کاربردی و محاسباتی در مکانیک

Article 9, Volume 26, Issue 2 - Serial Number 12, September 2015, Pages 119-128   

Document Type: مقاله کوتاه

DOI: 10.22067/fum-mech.v26i2.29652

Authors

Ahmad Rahmati-Alaei; mohsen ghazanfari; majid shahravi^*

Iran University of Science & Technology

Abstract

Impact energy absorption systems in various industries such as automotive and railway have a particular importance to minimize the impact on passengers and enhance vehicle safety. This paper focuses on the bending collapse behavior of thin-walled energy absorber with circular and square cross sections. The theory that is applied is global energy equilibrium and the prevalent bending collapse mode for obtaining the relationship is considered. On the same basis, obtained relations are compared with the published results for the bending strength of tubular structures which were derived from experimental and analytical studies. Subsequently by using the derived bending strength formula, simplified models for circular and square tubes is introduced. The main advantage of these simplified models as a critical modeling technique is dramatically reducing the time of computer simulation in early design stages with the results close to the original model. For this purpose, by axial crash simulation of curved tube by using nonlinear dynamic finite element software LS-DYNA, the results are compared to verify the efficiency of the proposed simplified model and the accuracy of the derived relationship for tube’s bending strength.

Keywords

Energy absorber; Circular-square; Crash; Bending collapse; Simplified model

References

1. Liu YC, Day ML. "Simplified modelling of thin walled box section beam", I.J. Crash, Vol. 11,

No. 3, pp. 263–272, (2006).

2. Hamza K, Saitou K, "Design optimization of vehicle structures for crashworthiness using equivalent mechanism approximations", Journal of Mechanical Design, pp. 127 / 485, (2005).

3. Liu, Y.C., "Development of simplified models for crashworthiness analysis", PhD thesis, Louisville, University of Louisville, (2005).

4. Wierzbicki, T., Recke, L., Abramowicz, W. and Gholami, T., "Stress profiles in thin-walled prismatic columns subjected to crush loading", I. Compression. ComputStruct, pp. 51(6):611–23. (1994).

5. Wierzbicki, T., Recke, L., Abramowicz, W., Gholami, T. and Huang, J., "Stress profiles in thin-walled prismatic columns subjected to crush loading"—II. Bending. Comput. Struct., pp. 51(6):

623–41, (1994).

6. Kecman, D., "Bending collapse of rectangular and square section tubes", Int. J. MechSci, pp. 25

(9–10) 623–36, (1983).

7. Abramowicz, W., "Simplified crushing analysis of thin-walled columns and beams", RozprInzEng Trans, pp. 29(1):5–26, (1981).

8. Zheng, L. and Wierzbicki, T., "Quasi-static crushing of S-shaped aluminum front rail", Int. J. crashworthiness, pp. 9(2):155–73, (2004).

9. Mamalis, A., Manolakos, D., Loannidis M. and Kostazos, P., "Bending of cylindrical steel tubes: numerical modeling", Int. J. Crashworthiness, pp. 11(1):37–47, (2006).

10. Kim, HS, Kang, SY, Lee, IH, Park, SH. and Han, D.C. "Vehicle frontal crashworthiness analysis by simplified structure modeling using nonlinear spring and beam elements", Int. J. crashworthiness, pp. 2(1):107–17, (1996).

11. خلخالی، ابوالفضل، درویزه، ابوالفضل، نریمان زاده، نادر و معصومی،ابوالفضل.، «تحلیل تئوریک تغییر شکل‌های بزرگ در جاذب‌های انرژی S شکل»، هفدهمین کنفرانس سالانه مهندسی مکانیک، تهران، (1388).