Mechanical properties of electrospun silk fibroin / poly( ε-caprolactone)nanofibrous membranes under biaxial tensile loads with different tensile rates

Biaxial tensile tests of electrospun silk fibroin( SF) / poly( e-caprolactone)( PCL) composite nanofibrous membranes were done in this paper. The biaxial tensile failure experiment was carried out under tensile rate ratios of 1∶ 1,2 ∶ 1,5 ∶ 1,8 ∶ 1,and the biaxial cyclic tensile experiment were carried out under tensile rate ratios of 1∶ 1,2∶ 1,4∶ 1,5∶ 1,8∶ 1. The results indicate that the tensile breaking load of electrospun composite nanofibrous membranes is closely related to the tensile rate ratios,and the biaxial tensile mechanical properties under cyclic loads are nonlinear and inelastic. In this paper,mathematical model describing the relationship between tensile loading and stretch rate during biaxial cyclic tensile testing was established through fitting the experimental curve,and it was applied to biaxial cyclic tensile testing under tensile rate ratio of 4 ∶ 1. The consistence of the modeling and experimental curves verifies that the mathematical model is effective.