Gradient model of bending of a composite beam
UDC
539.3DOI:
https://doi.org/10.31429/vestnik-19-2-6-16Abstract
Size-dependent models of beam bending have attracted increased attention of scientists in recent years. The gradient theory of elasticity is used for the correct description of experimental data for micro-dimensional beams. However, the problem of obtaining simplified analytical expressions for moments and deflections of a composite beam remains unexplored. A study of the problem of bending a composite Euler-Bernoulli beam taking into account large-scale effects is carried out. To account for the size effects, the one-parameter gradient model of Aifantis is used. One end of the beam is rigidly fixed. Three types of beam loading are considered: 1) evenly distributed transverse force; 2) bending moment; 3) transverse force at the other end of the beam. Within the framework of the gradient theory of elasticity, the problem is formulated in terms of the bending moment, while additional boundary conditions and conjugation conditions are set. Bending moments are represented as the sum of solutions of the problem in the classical formulation and additional gradient terms. Simplified asymptotic expressions for gradient terms for small values of the scale parameter are obtained for each type of load. The limits of applicability of the asymptotic approach are investigated. Analytical formulas for finding the deflection of the middle line of the beam under arbitrary laws of inhomogeneity of bending stiffness are obtained. Calculations of moments and deflection, both in the case of homogeneous and inhomogeneous parts of the beam, are carried out on specific examples. The following was found out: bending moments experience a jump on the interface surface; deflections are continuous; an increase in the scale parameter leads to a decrease in the deflection value. The dependence of the moment jump on the flexural stiffness modules and the scale parameter is investigated. A comparative study of the influence of the value of the inhomogeneity parameter on the deflection distribution was carried out.
Keywords:
gradient theory of elasticity, bending moment, composite beam, Euler-Bernoulli model, asymptotic solution, inhomogeneous materialsAcknowledgement
References
- Papargyri-Beskou S., Tsepoura K., Polyzos D., Beskos D. Bending and stability analysis of gradient elastic beams. Int. J. Solids Struct., 2003, vol. 40, iss. 2, pp. 385–400. DOI 10.1016/S0020-7683(02)00522-X
- Niiranen J., Balobanov V., Kiendl J., Hosseini S. Variational formulations, model comparisons and numerical methods for Euler–Bernoulli micro-and nano-beam models. Math. Mech. Solids, 2017, vol. 24, iss. 1, pp. 312–335. DOI 10.1177/1081286517739669
- Lurie S., Solyaev Y. Revisiting bending theories of elastic gradient beams. Int. J. Eng. Sci, 2018, vol. 126, pp. 1–21. DOI 10.1016/j.ijengsci.2018.01.002
- Lurie S., Solyaev Y. On the formulation of elastic and electroelastic gradient beam theories. Continuum Mech. Thermodyn., 2019, pp. 1–13. DOI 10.1007/s00161-019-00781-3
- Ломакин Е.В., Лурье С.А., Рабинский Л.Н., Соляев Ю.О. Об уточнении напряженного состояния в прикладных задачах теории упругости за счет градиентных эффектов. Доклады Академии наук, 2019, т. 489, № 6, с. 585–591 [Lomakin E.V., Lurie S.A., Rabinskiy L.N., Solyaev Y.O. Refined stress analysis in applied elasticity problems accounting for gradient effects. Doklady Physics, 2019, vol. 64, no. 12, pp. 482-486] DOI 10.31857/S0869-56524896585-591
- Lam D.C., Yang F., Chong A.,Wang J., Tong P. Experiments and theory in strain gradient elasticity. J. Mech. Phys. Solids, 2003, vol. 51, iss. 8, pp. 1477–1508. DOI 10.1016/S0022-5096(03)00053-X
- Toupin R.A. Elastic materials with couple-stresses. Arch. Rational Mech. Anal., 1962, vol. 11, pp. 385–414. DOI 10.1007/BF00253945
- Mindlin R.D. Micro-structure in linear elasticity. Arch. Rational Mech. Anal., 1964, vol. 16, pp. 51–78. DOI 10.1007/BF00248490
- Aifantis E.C. Gradient effects at the macro, micro and nano scales. JMBM, 1994, vol. 5, pp. 335–353. DOI 10.1515/JMBM.1994.5.3.355
- Altan B.S., Aifantis E.C. On some aspects in the special theory of gradient elasticity. JMBM, 1997, vol. 8, pp. 231–282. DOI 10.1515/JMBM.1997.8.3.231
- Лурье С.А., Белов П.А., Рабинский Л.Н., Жаворонок С.И. Масштабные эффекты в механике сплошных сред. Материалы с микро- и наноструктурой. Москва, Издательство МАИ, 2011 [Lurie S.A., Belov P.A., Rabinskiy L.N., Zhavoronok S.I. Scale effects in continuum mechanics. Materials from micro- and nanostructures. Moscow, Izdatelstvo MAI, 2011. (in Russian)]
- Лурье С.А., Соляев Ю.О., Рабинский Л.Н., Кондратова Ю.Н., Волов М.И. Моделирование напряженно-деформированного состояния тонких композитных покрытий на основе решения плоской задачи градиентной теории упругости для слоя. Вестник Пермского национального исследовательского политехнического университета. Механика, 2013, № 1, с. 161–181 [Lurie S.A., Solyaev Yu.O., Rabinsky L.N., Kondratova Yu.N., Volov M.I. Simulation of the stress-strain state of thin composite coating based on solutions of the plane problem of strain-gradient elasticity for layer. Vestnik PNIPU. Mekhanika – PNRPU Mechanics Bulletin, 2013, no. 1, pp. 161–181. (in Russian)]
- Li A., Zhou S., Zhou S., Wang B. A size-dependent bilayered microbeam model based on strain gradient elasticity theory. Compos. Struct., 2014, vol. 108, pp. 259–266. DOI 10.1016/j.compstruct.2013.09.020
- Fu G., Zhou S., Qi L. The size-dependent static bending of a partially covered laminated microbeam. Int. J. Mech. Sci., 2019, vol. 152, pp. 411–419. DOI 10.1016/j.ijmecsci.2018.12.037
- Asghari M., Ahmadian M.T., Kahrobaiyan M.H., Rahaeifard M. On the size dependent behavior of functionally graded micro-beams. Mater Des., 2010, vol. 31, pp. 2324–2333. DOI 10.1016/J.MATDES.2009.12.006
- Kahrobaiyan M.H., Rahaeifard M., Tajalli S.A., Ahmadian M.T. A strain gradient functionally graded Euler–Bernoulli beam formulation. Int J Eng Sci., 2012, vol. 52, pp. 65–76. DOI 10.1016/J.IJENGSCI.2011.11.010
- Salamat-talab M., Shahabi F., Assadi A. Size dependent analysis of functionally graded microbeams using strain gradient elasticity incorporated with surface energy. Appl Math Modell., 2012. DOI 10.1016/j.apm.2012.02.053
- Eltaher M.A., Khairy A., Sadoun A.M., Omar F.A. Static and buckling analysis of functionally graded Timoshenko nanobeams. Appl Math Comput., 2014, vol. 229, pp. 283–295. DOI 10.1016/j.amc.2013.12.072
- Li L., Hu Y. Post-buckling analysis of functionally graded nanobeams incorporating nonlocal stress and microstructure-dependent strain gradient effects. Int J Mech Sci., 2017, vol. 120, pp. 159–170. DOI 10.1016/j.ijmecsci.2016.11.025
- Momeni S.A., Asghari M. The second strain gradient functionally graded beam formulation. Composite Structures, 2018, pp. 1–37. DOI 10.1016/j.compstruct.2017.12.046
- Ватульян А.О., Нестеров С.А. Решение задачи градиентной термоупругости для полосы с покрытием. Учен. зап. Казан. ун-та. Сер. Физ.-матем. науки, 2021, т. 163, кн. 2, с. 181–196 [Vatulyan A.O., Nesterov S.A. Solution of the problem of gradient thermoelasticity for a coated strip. Uchenye Zapiski Kazanskogo Universiteta. Seriya Fiziko-Matematicheskie Nauki, 2021, vol. 163, no. 2, pp. 181–196. (In Russian)] DOI 10.26907/2541-7746.2021.2.181-196
- Vatulyan А.О., Nesterov S.А. On the deformation of a composite rod in the framework of gradient thermoelasticity. Materials Physics Mechanics, 2020, vol. 46, pp. 27–41. DOI 10.18149/MPM.4612020_3
- Ватульян А.О., Нестеров С.А., Юров В.О. Решение задачи градиентной термоупругости для цилиндра с термозашитным покрытием. Вычислительная механика сплошных сред, 2021, т. 14, № 3, с. 253–263 [Vatulyan A.O., Nesterov S.A., Yurov V.O. Solution of the gradient thermoelasticity problem for a cylinder with a heat-protected coating. Computational continuum mechanics, 2021, vol. 14, no. 3, pp. 253–264 (in Russian)] DOI 10.7242/1999-6691/2021.14.3.21
- Ватульян А.О., Нестеров С.А., Юров В.О. Исследование напряженно-деформированного состояния полого цилиндра с покрытием на основе градиентной модели термоупругости. Вестник Пермского национального исследовательского политехнического университета. Механика, 2021, № 4, с. 60–70 [Vatulyan А.О., Nesterov S.А., Yurov V.О. Investigation of the stress-strain state of a hollow cylinder with a coating based on the gradient model of thermoelasticity. PNRPU Mechanics Bulletin, 2021, no. 4, pp. 60–70. (In Russian)] DOI 10.15593/perm.mech/2021.4.07
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