Consideration of physical nonlinearity in the calculation of a flat reinforced concrete slab using the SCAD software

The aim of the paper is to analyze the results of the determination of forces and motions in a flat slab under static load, obtained considering the physically nonlinear operation of reinforced concrete. The deformation theories used for composite materials were compared. A linear analysis was carried out, along with a nonlinear automated analysis of forces and motions in a slab in the SCAD Office software (version 21.1.9.7) based on various deformation theories. An automatic calc ulation of a slab was conducted in accordance with the guidelines of the SP 52 -103-2007 “Concrete monolithic building structures”, according to which the nonlinear operation of reinforced concrete structural elements should be considered by introducing reducing coefficients. A comparative analysis of the obtained forces and motions in a flat reinforced concrete slab was carried out. An inconsistency was found between the values calculated based on the theory of physical nonlinearity and 

those calculated according to the recommendations of SP 52-103-2007. In comparison with the nonlinear analysis based on SP 52-103-2007, the maximum error comprised 55.8%. The obtained values of motions, according to the recommendations of SP 52-103-2007, were also inconsistent. The largest discrepancy in the results of the nonlinear analysis was 49.4%, while the largest discrepancy in the linear analysis was 69%. Thus, the study showed inconsistency between the results obtained using the guidelines and the results of linear and non-linear analysis. The difference in the results demands additional verification when using non-linear analysis in calculations for strength and stiffness as a means of clarifying the stress-strain state of the studied structure.

1. Evseev NA. Accounting of physical nonlinearity of reinforced concrete structures at computation of structural systems. Vestnik grajdanskih ingenerov = Bulletin of Civil Engineers. 2017;5(64):66-70. (In Russ.) https://doi.org/10.23968/1999-5571-2017-14-5-66-70

2. Zalesov AS, Mukhamediev TA, Chistyakov EA. Physical nonlinearity accounting for calculation of reinforced concrete monolithic structures of high-rise buildings. Stroitel’naya mehanika I raschet soorujeniy = Structural Mechanics and Analysis of Constructions. 2005;1:4–8. (In Russ.)

3. Blokhina NS. The problem of physical nonlinearity accounting in the building structures calculation. Vestnik MGSU. 2011;6:384–387. (In Russ.)

4. Teplykh AV. The use of shell elements for calculation of building steel structures in the SCAD and Nastran programs with due regard for geometrical and physical nonlinearities. Promyshlennoe I grajdanskoe stroitel’stvo = Industrial and civil engineering. 2011;6:49–52. (In Russ.)

5. Teplykh AV. Application of shell and solid elements in the analysis of building steel structures in the SCAD and Nastran software taking into account geometrical and physical nonlinearity. Inzhenerno-stroitel'nyi zhurnal = Magazine of Civil Engineering. 2011;3:4–20. (In Russ.) https://doi.org/10.18720/MCE.21.4

6. Perelmuter AV, Tur VV. Whether we are ready to proceed to a nonlinear analysis at designing? Mezhdunarodnyi zhurnal po raschetu grazhdanskikh i stroitel'nykh konstruktsii = International Journal for Computational Civil and Structural Engineering. 2017;13(3):86–102. (In Russ.)

7. Gorodetsky AS, Batrak LG, Gorodetsky DA, Laznyuk MV, Yusipenko SV. Calculation and design of structures of high-rise buildings made of monolithic reinforced concrete. Kiev, Fact; 2004. 106 p. (In Russ.)

8. Fialko SYu. Quadrilateral shell finite element for analysis of thin-walled reinforced concrete structures. Inzhenerno-stroitel'nyi zhurnal = Magazine of Civil Engineering. 2014;5(49):27–36. (In Russ.) https://doi.org/10.5862/MCE.49.3

9. Fialko SYu. Application of finite element method to analysis of strength and bearing capacity of thin-walled reinforced concrete structures taking into account physical nonlinearity. Moscow, ASV; 2018. 192 p. (In Russ.)

10. Korsun VI, Niedoriezov AV, Makarenko SYu. Comparative analysis of the strength criteria for concrete. Sovremennoe promyshlennoe I grajdanskoe stroitel’stvo = Modern industrial and civil engineering. 2014;1:65–78. (In Russ.)

11. Skvortsov YuV. Plasticity and creep theories. Samara, SGAU; 2013. 85 p. (In Russ.)

12. Taranukha NA, Vasilyev AS. An analysis of limit state criteria for the construction of composite materials. Uchenye zapiski KnAGTU = Scholarly Notes of Komsomolsk-naAmure State Technical University. 2015;III1(23):81–87. (In Russ.)

13. Klovanich SF, Mironenko IN. Finite element method in reinforced concrete mechanics. Odessa, ONMU; 2007. 110 p. (In Russ.)

14. Fialko SYu, Perelmuter AV. Inelastic analysis of reinforced concrete structures in SCAD. International Journal for Computational Civil and Structural Engineering. 2019;15(1):54–60. https://doi.org/10.22337/2587-9618-2019-15-1-54-60

15. Fialko SYu, Karpilovskyi VS. Triangular and quadrilateral flat shell finite elements for nonlinear analysis of thin-walled reinforced concrete structures in SCAD software. Proceedings of the 11th International Conference "Shell Structures: Theory and Applications”, (SSTA 2017). 11-13th October 2017, Gdansk, Poland. Gdansk, 2017;4:367–370. https://doi.org/10.1201/9781315166605-83

16. Geraymovich YD, Yevzerov ID, Marchenko DV. The new physically nonlinear finite elements in software package LIRA 10.8. International Journal for Computational Civil and Structural Engineering. 2019;15(1):61–66. https://doi.org/10.22337/2587-9618-2018-15-1-61-66

17. Hagsten LG, Rasmussen AB, Fisker J. Strain capacity of reinforced concrete members subjected to uniaxial tension. Procedia engineering. 2017;172:338–346. https://doi.org/10.1016/j.proeng.2017.02.038

18. Tur V, Nadolski V. A first attempt to determine the partial factors according to Eurocodes for the verification of ULS of steel elements for conditions of the Republic of Belarus. Journal of Sustainable Architecture and Civil Engineering. 2016;1/14:44–50. https://doi.org/10.5755/j01.sace.14.1.15066

19. Rudykh OL, Sokolov GP, Pakhomov VL. Introduction to nonlinear construction mechanics. Мoscow, ASV;1998. 103 p. (In Russ.)