Shape memory polymers store and recover an original shape. Nowadays, the design of devices based on this material demands modeling of its thermomechanical behavior, some of which have been developed considering the ma...
详细信息
Shape memory polymers store and recover an original shape. Nowadays, the design of devices based on this material demands modeling of its thermomechanical behavior, some of which have been developed considering the material is composed of glassy and active phases. Following this assumption, this work develops a constitutive model of flow stress of shape memory polymers by a temperature induced glassy-active phase transformation approach. Experimental strain-temperature data from literature are adapted to describe the phase transformation. The resulting expression is: ( ) ( ) 1 1 [1 ( ) ] {1 [1 ( ) ] } A T T A T T SMP as as af af g a a g g t g t d d T T E E T d T d α α ε ε σ ε ε ε ε ? ? ? ? ? ? ? ? = ? ? + ? + ? ? ? + ? It is function of the microstructure, material temperature, glass transition and transformation temperatures. Compared with others models, this one results easy for programming on finite element analysis. The predicted stress results coincide with experimental data, therefore, the estimation of a phase transformation from the recovery of strain results valid and the grade of approximation of the model is appropriate.
暂无评论