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A simple limit analysis procedure for reinforced concrete slabs using rigid finite elements

  • Ahmed, H. (Jacobs UK Limited) ;
  • Gilbert, M. (Department of Civil and Structural Engineering, University of Sheffield)
  • Received : 2021.08.02
  • Accepted : 2022.09.18
  • Published : 2022.10.10

Abstract

It has previously been proposed that the yield-line method of analysis for reinforced concrete slabs could be automated via the use of rigid finite elements, assuming all deformations occur along element edges. However, the solutions obtained using this approach can be observed to be highly sensitive to mesh topology. To address this, a revised formulation that incorporates modified yield criteria to account for the presence of non-zero shear forces at interfaces between elements is proposed. The resulting formulation remains simple, with linear programming (LP) still used to obtain solutions for problems involving Johansen's square yield criteria. The results obtained are shown to agree well with literature solutions for various slab problems involving uniform loading and a range of geometries and boundary conditions.

Keywords

References

  1. Ahmed, H.M. (2005), "Limit analysis of structures: Novel computational techniques", PhD Thesis, The University of Sheffield, Department of Civil Engineering, UK.
  2. Al-Sabaha, A. and Falter, H. (2013), "Finite element lower bound yield line analysis of isotropic slabs using rotation-free elements", Eng. Struct., 53, 38-51. https://doi.org/10.1016/j.engstruct.2013.03.005.
  3. Balasubramanyam, K.V. and Kalyanaraman, V. (1988), "Yield line analysis by linear programming", ASCE J. Struct. Eng., 114, 1431-1437. https://doi.org/10.1061/(ASCE)0733-9445(1988)114:6(1431).
  4. Bleyer, J. and De Buhan, P. (2013), "On the performance of nonconforming finite elements for the upper bound limit analysis of plates", Int. J. Numer. Meth. Eng., 94(3), 308-330. https://doi.org/10.1002/nme.4460.
  5. Chan, H.S.Y. (1972), "The collapse load of reinforced concrete plates", Int. J. Numer. Meth. Eng., 5, 57-64. https://doi.org/10.1002/nme.1620050106.
  6. Cohn, M.Z., Ghosh, S.K. and Parimi, S.R. (1972), "Unified approach to theory of plastic structures", J. Eng. Mech. Div., 98, 1133-1158. https://doi.org/10.1061/JMCEA3.0001659.
  7. De Filippo, M. and Kuang, J.S. (2021), "Pseudo-lower bound method for assessing concrete slabs", Proc. Inst. Civil Eng.-Struct. Build., 174(11), 903-919. https://doi.org/10.1680/jstbu.18.00130.
  8. Fox, E.N. (1974), "Limit analysis for plates: The exact solution for a clamped square plate of isotropic homogeneous material obeying the square yield criterion and loaded by uniform pressure", Philos. Tran. Roy. Soc. A, 277, 121-155. https://doi.org/10.1098/rsta.1974.0047.
  9. Gilbert, M., Casapulla, C. and Ahmed, H.M. (2006), "Limit analysis of masonry block structures with nonassociative frictional joints", Comput. Struct., 84(13-14), 873-887. https://doi.org/10.1016/j.compstruc.2006.02.005.
  10. Gilbert, M., He, L., Smith, C.C. and Le, C.V. (2014), "Automated yield-line analysis of slabs using discontinuity layout optimization", Proc. Roy. Soc. A, 470(2168), 20140071. https://doi.org/10.1098/rspa.2014.0071.
  11. He, L., Gilbert, M. and Shepherd, M. (2017), "Automatic yieldline analysis of practical slab configurations via discontinuity layout optimization", J. Struct. Eng., 143(7), 04017036. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001700
  12. Ho, P.L.H., Le, C.V. and Tran-Cong, T. (2018), "Limit state analysis of reinforced concrete slabs using an integrated radial basis function based mesh-free method", Appl. Math. Model., 53, 1-11. https://doi.org/10.1016/j.apm.2017.08.006.
  13. Jackson, A.M. and Middleton, C.R. (2013), "Closely correlating lower and upper bound plastic analysis of real slabs", Struct. Eng., 91(1), 34-40.
  14. Johnson, D. (1994), "Mechanism determination by automated yield-line analysis", Struct. Eng., 72(19), 323-327.
  15. Johnson, D. (1995), "Yield line analysis by sequential linearprogramming", Int. J. Solid. Struct., 32(10), 1395-1404. https://doi.org/10.1016/0020-7683(94)00200-G.
  16. Johnson, R.P. (1967), Structural Concrete, McGraw-Hill, London UK.
  17. Keyvani, S. and Vaez, S.R.H. (2019), "Using DLO procedure to investigate the effect of openings on ultimate load and collapse pattern of slabs", Struct., 20, 717-727. https://doi.org/10.1016/j.istruc.2019.06.023.
  18. Le, C.V., Nguyen, P.H. and Chu, T.Q. (2015), "A curvature smoothing Hsieh-Clough-Tocher element for yield design of reinforced concrete slabs", Comput. Struct., 152, 59-65. https://doi.org/10.1016/j.compstruc.2015.02.009.
  19. Liu, T. (1999), "Automatic computational method for yield line analysis", Struct. Eng. Mech., 8, 311-324. https://doi.org/10.12989/sem.1999.8.3.311.
  20. Makrodimopoulos, A. (2020), "A fundamental class of stress elements in lower bound limit analysis", Proc. Roy. Soc. A, 476(2243), 20200425. https://doi.org/10.1098/rspa.2020.0425.
  21. Mosek (2018), The MOSEK Optimization Tools Manual. Version 8.1 Edition, http://www.mosek.com.
  22. Munro, J. and Da Fonseca, A.M.A. (1978), "Yield line method by finite elements and linear programming", Struct. Eng., 56(2), 37-44.
  23. Nielsen, M.P. and Hoang, L.C. (2010), Limit Analysis and Concrete Plasticity, Third Edition, CRC Press, New York
  24. Regan, P.E. and Yu, C.W. (1973), Limit State Design of Structural Concrete, Chatto and Windus, London, UK.
  25. Save, M.A. and Massonnet, C.E. (1974), Plastic Analysis and Design of Plates, Shells and Disks, North-Holland Publishing Company, Amsterdam-London.
  26. Smith, C. and Gilbert, M. (2007), "Application of discontinuity layout optimization to plane plasticity problems", Proc. Roy. Soc. A, 463(2086), 2461-2484. https://doi.org/10.1098/rspa.2006.1788.
  27. Sobotka, Z. (1989), Theory of Plasticity and Limit Design of Plates, Academia, Prague, Czech Republic.
  28. Tamura, T., Kobayashi, S. and Sumi, T. (1987), "Limit analysis of soil structure by rigid-plastic finite element method", Soil. Found., 24(1), 34-42. https://doi.org/10.3208/sandf1972.24.34.
  29. Thavalingam, A., Jennings, A., McKeown, J.J. and Sloan, D. (1998), "A computerised method for rigid-plastic yield-line analysis of slabs", Comput. Struct., 68(6), 601-612. https://doi.org/10.1016/S0045-7949(98)00082-0.
  30. Thavalingam, A., Jennings, A., McKeown, J.J. and Sloan, D. (1999), "Computer-assisted generation of yield-line patterns for uniformly loaded isotropic slabs using an optimisation strategy", Eng. Struct., 21(6), 488-496. https://doi.org/10.1016/S0141-0296(97)00228-9.