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Translated from Mekhanika Kompozitnykh Materialov, Vol. 53, No. 4, pp. 653-674 , July-August, 2017.
The creep of homogenous and hybrid composite beams of an irregular laminar fibrous structure is investigated. The beams consist of thin walls and flanges (load-carrying layers). The walls may be reinforced longitudinally or crosswise in the plane, and the load-carrying layers are reinforced in the longitudinal direction. The mechanical behavior of phase materials is described by the Rabotnov nonlinear hereditary theory of creep taking into account their possible different resistance to tension and compression. On the basis of hypotheses of the Timoshenko theory, with using the method of time steps, a problem is formulated for the inelastic bending deformation of such beams with account of the weakened resistance of their walls to the transverse shear. It is shown that, at discrete instants of time, the mechanical behavior of such structures can formally be described by the governing relations for composite beams made of nonlinear elastic anisotropic materials with a known initial stress state. The method of successive iterations, similar to the method of variable parameters of elasticity, is used to linearize the boundary-value problem at each instant of time. The bending deformation is investigated for homogeneous and reinforced cantilever and simply supported beams in creep under the action of a uniformly distributed transverse load. The cross sections of the beams considered are I-shaped. It is found that the use of the classical theory for such beams leads to the prediction of indefensibly underestimated flexibility, especially in long-term loading. It is shown that, in beams with reinforced load-carrying layers, the creep mainly develops due to the shear strains of walls. It is found that, in short- and long-term loadings of composite beams, the reinforcement structures rational by the criterion of minimum flexibility are different.
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Yu. V. Nemirovskii, A. V. Mischenko, and I. T. Vokhmyatin, “Rational and optimal design of layered rod systems,” Izd. NGASU, Novosibirsk (2004).
J. A. Purkiss, P. J. Wilson, and P. Blagojević, “Determination of the load-carrying capacity of steel fibre reinforced concrete beams,” Compos. Struct., 38, Nos. 1-4, 111-117 (1997). CrossRef
Yu. V. Nemirovskii and A. A. Baturin, “Calculation method of deformation and strength of T- and I-profile reinforced concrete rods,” Izd. Vuz., Stroitel’stvo, No. 10, 82-93 (2015).
Yu. N. Rabotnov, Creep of Structural Elements [in Russian], M., Nauka (1966).
Yu. N. Rabotnov, Elements of Hereditary Mechanics of Solids [in Russian], Nauka, Fizmatgiz (1977).
V. V. Karpov, Strength and Stability of Stiffened Shells of Rotation. In 2 parts. Pt. 2. Computational Experiment at a Static Mechanical Action [in Russian], M., Fizmatlit, (2011).
G. A. Chami, M. Theriault, and K W. Neale, “Creep behaviour of CFRP-strengthened reinforced concrete beams,” Construct. Build. Mater., 23, No. 4, 1640-1652 (2009). CrossRef
A. P. Yankovskii, “Investigation of the steady creep of metal-composite beams of layered-fibrous structure with account of weakened resistance to transverse shears,” Vest. Samarsk. Gos. Tekhn. Univ., Ser. Fiz. Mat. Nauki, 20, No. 1, 85-108 (2016).
M. Kh. Ahmetzyanov, P. V. Gres, and I. B. Lazarev, Strength of Materials [in Russian], M., Vissh. Shkola (2007).
K. Vasidzu, Variational Methods in the Theory of Elasticity and Plasticity [Russian translation], M., Izd. Mir (1987).
A. V. Perel’muter and V. I. Slivker, Stability of Structural Equilibrium and Related Problems [in Russian], 1, M., Izd. SKAD SOFT (2007).
A. K. Malmeister, V. P. Tamužs, and G. A. Teters, Strength of Polymer and Composite Materials [in Russian], Zinatne, Riga (1980).
A. F. Nikitenko, Creep and Long-term Strength of Metallic Materials [in Russian], NGASU, Novosibirsk, (1997).
А. A. Il’yushin, Proceedings., 3. Theory of Thermoviscoelasticity [in Russian]. Eds. E. А. Il’yushina and V. G. Tunguskova, M., Fizmatlit (2007).
A. A. Treshchev, Isotropic Plates and Shells Made of Materials Sensible to the Type of Stress State [in Russian], M., Tula, RAASN, Izd. TulGU (2013).
R. M. Goldhoff, “The application of Rabotnov’s creep parameter,” Proc. ASTM, 61 (1961).
F. H. Turner and K. E. Blomquist, “A study of the applicability of Rabotnov’s creep parameter for aluminium alloy,” JAS, 23, No. 12 (1956).
A. P. Yankovskii “Modeling the creep of rib-reinforced composite media from nonlinear hereditary phase materials. 1. Structural model,” Mech. Compos. Mater., 51, No. 1, 1-16 (2015). CrossRef
A. P. Yankovskii, “Modeling the mechanical behavior of composites with a spatial reinforcement of nonlinear hereditary materials,” Struct. Compos. Mater., No 2, 12-25 (2012).
Composite Materials. Handbook [in Russian]. Ed. D. M. Karpinos, Naukova Dumka, Kiev (1985).
- Study on the Unsteady Creep of Composite Beams with an Irregular Laminar Fibrous Structure Made from Nonlinear Hereditary Materials
A. P. Yankovskii
- Springer US
in-adhesives, MKVS, Hellmich GmbH/© Hellmich GmbH, Zühlke/© Zühlke