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Nonlinear behavior of
thermally loaded curved sandwich panels with a transvesely
flexible core
Yeoshua Frostig and Ole Thomsen |
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Vol. 4 (2009), No. 7-8, 1287–1326
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Abstract |
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The nonlinear analysis of a curved sandwich panel with a compliant core subjected to a thermal field and mechanical load is presented. The mathematical formulation is developed first, along with the solution of the stress and displacement fields for the case of a sandwich core with mechanical properties that are independent of the temperature. The nonlinear analysis includes geometrical nonlinearities in the face sheets caused by rotation of the face cross sections and high-order effects due to the transversely flexible core. The mathematical formulation uses the variational principle of minimum energy along with HSAPT (high-order sandwich panel theory) to derive the nonlinear field equations and the boundary conditions. The full displacement and stress fields of the core with uniform temperature-independent mechanical properties and the appropriate governing equations of the sandwich panel are given. This is followed by the general solution of the core stress and displacement fields when the mechanical core properties are dependent on the radial (through-the-thickness) coordinate. The displacement fields of a core with temperature-dependent mechanical properties are determined explicitly using an equivalent polynomial description of the varying properties. A numerical study then describes the nonlinear response of curved sandwich panels subjected to concentrated and distributed mechanical loads, thermally induced deformations, and simultaneous thermal and mechanical loads where the mechanical load is below the limit load level of the mechanical response and the imposed temperature field is made to vary. The results reveal that the thermomechanical response is linear when the sandwich panel is heated, but becomes nonlinear with limit point behavior when the panel is cooled down. |
Keywords
sandwich strcutures, thermal effects, nonlinear geometry,
softcore, high-order models
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Milestones
Received: 31 December 2008
Revised: 3 June 2009
Accepted: 4 June 2009
Published: 26 December 2009
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Authors |
| Yeoshua Frostig | |
| Professor, Ashtrom Engineering
Company Chair in Civil Engineering Technion - Israel Institute
of Technology Faculty of Civil and Environmental Engineering Haifa, 32000 Israel |
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| Ole Thomsen | |
| Professor, Head of Department
Aalborg University Department of Mechanical Engineering Pontoppidanstræde 105 9220 Aalborg Ø Denmark |
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