Thermomechanical behavior of granite under 150 °C: experimental and numerical analysis

The increasing need of structures having multiple functions orientates designers to combine materials in order to obtain, according to coupling scales, multi-materials structures. The lifetime of these structures represents the essential decisive element for study offices and manufacturers. The results of this work should add to the set of functional charges and constraints of resistance, the improvement of the lifetime as an objective to optimize a multi-material. In this study, we propose a numerical analysis by the finite elements method of the thermo mechanical behavior of these materials and their damage under thermal cyclic solicitations. The sample is a two-dimensional plate constituted of two different isotropic layers (steel, aluminum) submitted to variable thermal conditions (heat flux condition on one side and convection exchange condition on the opposite side). The sample is supposed to be fixed in one direction and free in the other. The damage model is based on the works of Lemaiˆtre and Chaboche [8]. Numerical results are presented for different forms of heat flux cycling (triangular, square and sinusoidal excitations) with a comparison of the multi-material damage for each excitation. The study is concluded by an empirical optimizing of the thickness of materials according to the total lifetime caused by thermo-mechanical effect.

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Finite Element Analysis on the Behavior of Laminated Composite Shells With Embedded Shape Memory Alloy Wires

Volume 10: Mechanics of Solids and Structures, Parts A and B ◽

10.1115/imece2007-41860 ◽

2007 ◽

Author(s):

H. K. Cho

Keyword(s):

Finite Element ◽

Numerical Analysis ◽

Shape Memory Alloy ◽

Shape Memory ◽

Laminated Composite ◽

Thermomechanical Behavior ◽

Nonlinear Finite Element ◽

Constitutive Law ◽

Composite Shells ◽

Laminated Composite Shells

Motivated by needs such as those in the aerospace industry, this paper demonstrates the thermomechanical characteristics of static and dynamic (frequency) behaviors of laminated composite shells with embedded shape memory alloy (SMA) wire subjected to temperature environments. Numerical analysis for SMA fiber reinforced composite laminates is performed by synergizing finite element method with Brison’s model [1,2] of SMA constitutive law. A nonlinear finite element procedure with respect to shape memory alloy hybrid composite (SMAHC) shell has been developed which incorporates a thermodynamically derived constitutive law for SMA behavior. Present illustrative applications involve rectangular laminated panels clamped along one side, although the method is applicable to more complicated laminates, geometries and boundary conditions. Panel geometry is discretized into specially-developed 3D degenerated eight-node laminated composite shell elements. General shell theory, involving incremental nonlinear finite element equilibrium that includes large deformations with Green-Lagrange strains, is employed. Several test cases which depend on volume fraction of SMA, temperature and ply angles are presented to illustrate the thermomechanical behavior of SMAHC. The results of numerical analysis show the ability of the suggested procedure to compute the thermomechanical behavior of SMAHC due to SMA’s internal phase transformations with stress and temperature.

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