A finite element model for shape memory behavior

Abstract

International audienceThis paper deals with a finite element implementation concerning the shape memory behavior. Shape memory behavior is usually driven by temperature changes. This model allows the simulation of problems integrating complex mechanical loading effects under random temperature variations. According to the relationship between stress and strain, the shape fixation during cooling phases and the memory effect during heating phase are modelised through a hereditary behavior needing incremental formulation developments. The step by step process introduces an additional fixed stress. Simulations request, for complex geometries including boundary conditions, a finite element approach. Thermodynamic developments are presented in order to define energetic balance and dissipations. In this paper, we propose to generalize this dependence of elastic modulus variations. A formulation for random mechanical loading and temperature variations is proposed. An experimental validation is proposed about shape memory alloy polymer DP5

Shape-memory behavior of cross-linked semi-crystalline polymers and their blends

“…However, a small number of scientific publications deals with theoretical description of SME, [34][35][36][37][38][39][40][41][42][43][44][45] especially in crosslinked semi-crystalline polymers [35,36,43,46]. Majority of authors consider predominantly amorphous SM polymers with the glass transition as a switching mechanism and entangled macromolecules as a network [34, 37-42, 44, 45].…”

Theoretical description of unconstrained thermally induced shape‐memory recovery in crosslinked polyethylenes

“…Only a small number of scientific publications deals with theoretical description of SME, especially in crosslinked semicrystalline polymers . However, majority of authors consider predominantly amorphous SM polymers with the glass transition as a switching mechanism and entangled macromolecules as a network (i.e., the first type of SM polymers) . Some authors compare results calculated on the basis of proposed approaches only with the experimental data received by Liu et al for amorphous resin at the programming deformations below 11% (relatively small deformation) .…”

“…However, majority of authors consider predominantly amorphous SM polymers with the glass transition as a switching mechanism and entangled macromolecules as a network (i.e., the first type of SM polymers) . Some authors compare results calculated on the basis of proposed approaches only with the experimental data received by Liu et al for amorphous resin at the programming deformations below 11% (relatively small deformation) . However, some works include only theoretical investigation without any comparison with experimental results; or there is a sharp disagreement between proposing theory and experimental findings .…”

“…Only a small number of scientific publications deals with theoretical description of SME, [10][11][12][13][14][15][16][17][18][19][20][21][22] especially in crosslinked semicrystalline polymers. 11,12,19,21 However, majority of authors consider predominantly amorphous SM polymers with the glass transition as a switching mechanism and entangled macromolecules as a network (i.e., the first type of SM polymers).…”

“…10,[13][14][15][16][17][18]20,22 Some authors compare results calculated on the basis of proposed approaches only with the experimental data received by Liu et al for amorphous resin at the programming deformations below 11% (relatively small deformation). 14,16,17,20 However, some works include only theoretical investigation without any comparison with experimental results; 11,12,15 or there is a sharp disagreement between proposing theory and experimental findings. 17 Only several scientific groups have tried their theoretical modeling of SM behavior for crosslinked semicrystalline SM polymers (i.e., for SM polymers of the second type) in case of the deformation about 100% and more.…”