Modeling the stretching of microporous membranes

Finite element modeling was used to predict the uni-axial deformation of microporous phase inversion membranes. Pore area, pore aspect ratio, and stress were studied as part of the modeling work. In order to adequately predict the change in pore shape due to the deformation two separate models were constructed. The models were formed in ABAQUS, a finite element solver commonly used for deformation modeling. One model predicts the initial phase of membrane deformation in which pores transition from a random alignment with respect to the direction of stretching to a uniform alignment in the direction of stretching. The second model is used to predict the deformation of the membrane pore structure after all pores have been aligned in the direction of stretching. Both models are successful in capturing the qualitative aspects of membrane deformation when compared to poly(vinylidene fluoride) membrane deformation data.