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Civil-Comp Proceedings ISSN 1759-3433
CCP: 79 PROCEEDINGS OF THE SEVENTH INTERNATIONAL CONFERENCE ON COMPUTATIONAL STRUCTURES TECHNOLOGY
Edited by: B.H.V. Topping and C.A. Mota Soares
Paper 33 Finite Element Analysis of the Influence of Temperature Profile on Thermoelasticity of Multilayered Plates
A. Robaldo Aerospace Department, Politecnico di Torino, Italy
Full Bibliographic Reference for this paper
A. Robaldo, "Finite Element Analysis of the Influence of Temperature Profile on Thermoelasticity of Multilayered Plates", in B.H.V. Topping, C.A. Mota Soares, (Editors), "Proceedings of the Seventh International Conference on Computational Structures Technology", Civil-Comp Press, Stirlingshire, UK, Paper 33, 2004. doi:10.4203/ccp.79.33
Keywords: thermal analysis, multilayered plates, higher order theories, unified formulation.
Summary
Thin-walled members of reactor vessels, turbines, as well as the structures of future
supersonic and hypersonic vehicles, such as high-speed civil transport and advanced
tactical fighters, are particularly susceptible to failure resulting from excessive stress
levels induced by thermal loadings.
For this reason the need for a better knowledge of the deflections and stresses induced
by thermal loads arose. Elevated thermal stresses at layer interfaces induce the origin
of failure mechanisms such as the debonding of layers and the developing of longitudinal
cracks. Thus, an accurate description of local stress fields in each layer becomes
mandatory also in the first stages of the design. Most of the early works represent
an attempt to include the effects of thermal loadings to the previous models for the
elastic analysis of multilayered plates such as the Classical Laminate Theory (CLT),
First Shear Deformation Theory (FSDT) or Higher-order Shear Deformation Theory
(HSDT). Murakami [1] asserted the superiority of the layer-wise description of
the unknowns since the intrinsic through-the-thickness variation of thermal loadings.
Bhaskar and Varadan [2], Ali et al. [3] recently pointed out the importance of refined
theories to handle thermal loadings accurately with respect to mechanical ones. An
assessment of the theories for thermoelastic analysis of laminated structures has been
given in [4]. Therefore, it appears clearly that appropriate structural modeling of multilayered
plates are required to satisfy what was summarized by the Carrera [4] with
the acronym -requirements. These are conditions on the displacement and stress
fields. In particular, they take into account the so-called zig-zag form of the displacement
field and the Interlaminar continuity for transverse stress field. On the basis of a
unified formulation, recently Carrera [5] investigated the influence of the temperature
profile through the thickness of the plate. The aim of that work has been to investigate
the errors introduced with the usual assumption of a linear through the thickness
profile of temperature. Indeed Tungikar and Rao [6] demonstrated, by solving the
heat conduction problem, how for a thick anisotropic laminate the temperature profile
shows a layerwise form differing considerably from the linear one. It is clear how the
inhomogeneity in the material properties causes a sever layerwise distortion of the
normal to the mid-surface for the moderately thick and thick beams [7]. In this work,
a finite element model based on the unified formulation introduced by Carrera is proposed
and applied. The possibility to develop both Equivalent Single Layer (ESL) and
Layer Wise (LW) descriptions of the unknown and to consider up to fourth-order expansions
along the thickness allows to compare and verify inside the same formulation
several different theories. Two different profile of temperature have been compared
on cross-ply simply supported plates: 1) the linear one 2) the actual profile obtained
by solving the heat conduction problem. A complete range of thickness ratios have
been considered in order to show how the transverse shear plays a even more significant
role increasing the thickness of the plate. The accuracy of the present model has
been verified comparing the results obtained with available exact solutions present in
literature.
References
- 1
- H. Murakami, "Assessment of plate theories for treating the thermomechanical response of layered plates", Composite Engineering, vol.3, no.2, pp.137-143, 1993. doi:10.1016/0961-9526(93)90038-L
- 2
- K. Bhaskar, T.K. Varadan, J.S.M. Ali, "Thermoelastic Solution for Orthotropic and Anisotropic Composites Laminates", Composites Part B, vol. 27, pp. 415-420, 1986. doi:10.1016/1359-8368(96)00005-4
- 3
- J.S.M. Ali, K. Bhaskar, T.K. Varadan, " new theory for accurate thermal/mechanical flexural analysis of symmetric laminated plates", Composite Structures, vol. 45, pp. 227-232, 1999. doi:10.1016/S0263-8223(99)00028-8
- 4
- E. Carrera, "An assessment of mixed and classical theories for thermal stress analysis of orthotropic plates", Journal of Thermal Stresses, vol 23, pp 797-831, 2000. doi:10.1080/014957300750040096
- 5
- E. Carrera, "Temperature Profile Influence on Layered Plates Response Considering Classical and Advanced Theories", American Institute of Aeronautics and Astronautics Journal, vol 40, pp 1885-1896, 2002. doi:10.2514/2.1868
- 6
- V.B. Tungikar, K.M. Rao, "Three dimensional exact solution of thermal stresses in rectangular composite laminate", Composite Structures, vol.27, pp.419-430,1994. doi:10.1016/0263-8223(94)90268-2
- 7
- Kapuria S., Dumir P.C., Ahmed A., "An efficient higher order zigzag theory for composite and sandwich beams subjected to thermal loading", International Journal of Solids and Structures, vol.40, pp.6613-6631, 2003. doi:10.1016/j.ijsolstr.2003.08.014
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