DOI QR코드

DOI QR Code

Plastic collapse of tapered, tip-loaded cantilevered beams

  • Wilson, James F. (Department of Civil and Environmental Engineering, Duke University) ;
  • El-Esnawy, Nayer A. (Department of Civil Engineering, Cairo University)
  • Published : 2000.06.25

Abstract

The plastic collapse loads and their locations are predicted for a class of tapered, initially curved, and transversely corrugated cantilevered beams subjected to static tip loading. Results of both closed form and finite element solutions for several rigid perfectly plastic and elastic perfectly plastic beam models are evaluated. The governing equations are cast in nondimensional form for efficient studies of collapse load as it varies with beam geometry and the angle of the tip load. Static experiments for laboratory-scale configurations whose taper flared toward the tip, complemented the theory in that collapse occurred at points about 40% of the beams length from the fixed end. Experiments for low speed impact loading of these configurations showed that collapse occurred further from the fixed end, between the 61% and 71% points. The results may be applied to the design of safer highway guardrail terminal systems that collapse by design under vehicle impact.

Keywords

References

  1. AI-Gahtani, H.J. (1996), "Exact stiffnesses for tapered members", Journal of Structural Engineering, 122(10), 1234-1239, https://doi.org/10.1061/(ASCE)0733-9445(1996)122:10(1234)
  2. Dinnik, A, (1932), "Design of columns of varying cross-section", Transactions of Applied Mechanics, 54(APM- 54-16), 165-171,
  3. EI-Esnawy, N.A. (1997), "Analysis and design of tandem vehicles and guardrail breakaway cable terminals for safer highways", Ph.D. Dissertation, Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina,
  4. Ermopoulos, J.C. (1986), "Buckling of tapered bars under stepped axial loads", Journal of Structural Engineering, 112(6), 1346-1354, https://doi.org/10.1061/(ASCE)0733-9445(1986)112:6(1346)
  5. Horne, M.R. (1979), Plastic Theory of Structures, 2nd ed., Pergamon Press, New York
  6. Horne, M.R. and Morris, L.J. (1982) Plastic Design of Low-Rise Frames, MIT Press, Cambridge, Massachusetts,
  7. Karabalis, D,L, and Besko, D.E. (1983), "Static, dynamic, and stability analysis of structures composed of tapered beams", Computers and Structures, 16(6), 731-748, https://doi.org/10.1016/0045-7949(83)90064-0
  8. Lee, H. and Goel, S. (1986), "Program EPFRAME: Elastic-plastic analysis of plane frames", Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI (unpublished).
  9. Maker, B,N., Ferencz, R.M. and Hallquist, J.O. (1991), NIKE3D: A Nonlinear, Implicit, Three-Dimensional Finite Element Code for Solid and Structural Mechanics-Users Manual, University of Califonia, Lawrence Livermore National Laboratory, Rept. UCRL-MA-105268.
  10. Pigman, J.G. and Agent, K.R. (1988), "Performance evaluation of breakaway-cable-terminal end treatments", Transportation Research Record 1198, TRB, National Research Council, 1-10,
  11. Siginer, A. (1992), "Buckling of columns of variable flexural rigidity", Journal of Engineering Mechanics, 118(3),640-643. https://doi.org/10.1061/(ASCE)0733-9399(1992)118:3(640)
  12. Timoshenko, S.P. and Gere, J.M. (1961), Theory of Elastic Stability, McGraw-Hill Book Company, Inc., New York.
  13. Williams, F.W and Aston, G. (1989), "Exact or lower bound tapered column buckling loads", Journal of Structural Engineering, 115(5), 1088-1100. https://doi.org/10.1061/(ASCE)0733-9445(1989)115:5(1088)
  14. Wilson, J.F. and EI-Esnawy, N.A. (1997), "The highway guardrail infrastructure: safer terminal design", Final Report, Contract No. NCHRP-34, Transportation Research Board, National Academy of Sciences, 1-32.
  15. Wilson, J.F. and Strong, D.J. (1997), "Elastic buckling of end-loaded tapered cantilevered beams with initial curvature", Structural Engineering and Mechanics, 5(3), 257-268. https://doi.org/10.12989/sem.1997.5.3.257
  16. Wolfram, S. (1993), Mathematica. A System for Doing Mathematics by Computer, 2nd ed., Addison-Wesley Publishing Company, Inc., New York.

Cited by

  1. Finite element linear and nonlinear, static and dynamic analysis of structural elements, an addendum vol.19, pp.5, 2002, https://doi.org/10.1108/02644400210435843