Similitude study on bending stiffness and behavior of composite tubes

Abstract

A procedure to design a composite tube that matches the flexural stiffness, load-carrying capacity, and energy absorption of an aluminum tube while subjected to bending load is of interest. The large deformation and energy absorption requirements are fulfilled through the progressive failure of the plies of suitable fiber orientations across the thickness of the tube. The layer wise nature of the composite tubes and cylindrical anisotropy, however, has impeded obtaining a simple closed-form solution for calculating the flexural stiffness. Available analytical solutions are mainly a complex set of equations, which should be solved simultaneously. In addition, the boundary and interface conditions between the adjacent plies must be satisfied. This article presents a straightforward simulation technique for this purpose. First, the tube is correlated to a corresponding composite sandwich panel, the flexural stiffness of which is obtained by the classical laminate theory. Then an analogous aluminum sandwich panel is designed and is correlated to a so-called ‘equivalent’ aluminum tube. The bending stiffness of the composite tube is shown to be the same as that of its equivalent aluminum tube. As a result, a complex problem of cylindrical anisotropy is mapped into a Cartesian coordinate system and solved via the classical laminate theory. The accuracy of the technique is verified by experimental work and analytical solutions. The agreement between the three methods is shown.

Keywords

Composite tube flexural stiffness large deformation thermoplastics progressive failure

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References

Derisi B. Development of thermoplastic composite tubes for large deformation. PhD Thesis, Concordia University, Montreal, Canada, 2008.

Derisi

Hoa

Hojjati

Fews

. Composite tube exhibiting large deformation under bending. J Compos Mater 2010; 44(16): 2005–2020.

Derisi

Hoa

Hojjati

Fews

. “Mechanical behavior of carbon/PEKK thermoplastic composite tubes under bending load”. J Thermoplast Compos Mater 2011; 24(1): 29–49.

Lekhnitskii

. Theory of elasticity of an anisotropic body, Moscow: Mir, 1981.

Jolicoeur

Cardou

. “Analytic solution for bending of coaxial orthotropic cylinders”. ASCE J Eng Mech 1994; 120: 2556–25745.

Chouchaoui

Ochoa

. “Similitude study for a laminated cylindrical tube under tensile, torsion, bending, internal and external pressure. Part I: governing equations”. Compos Struct 1999; 44: 221–229.

Ting

TCT

. “Pressuring, shearing, torsion and extension of a circular tube or bar of cylindrically anisotropic material”. Proc Roy Soc Lond 1999; A 455: 3527–3542.

Chen

Chung

Lin

. “A revisit of a cylindrically anisotropic tube subjected to pressuring, shearing, torsion and extension and a uniform temperature change”. Int J Solid Struct 2000; 37: 5143–5159.

Shadmehri

Derisi

Hoa

. “On bending stiffness of composite tube”. Compos Struct 2011; 93(9): 2173–2179.

10.

Librescu L and Song O. Thin-walled composite beams: theory and application. 1^st ed. New York: Springer.

11.

Xu D, Derisi B, Hoa, SV, Hojjati M and Fews R. Stress distributions of thermoplastic composite tubes subjected to four-point loading. In: The First Joint American-Canadian International Conference on Composites, Delaware, USA, 2009.