The Research Of Spandes Fiber Toughening Epoxy Shape Memory Polymer

The shape memory polymer has wide application prospect because of its shape memory effects.But because of its low strength,the application is limited.In order to improve its rigidity and strength,carbon fiber and other rigid reinforcing fibers were made into shape memory composites.But the research on improving its toughness is not so much,and there is often a requirement for toughness.This paper proposes a way to improve the toughness of epoxy shaped memory polymers by adding unidirectional spandex fiber.The transverse / longitudinal tensile modulus and tensile strength were deduced by theoretical analysis,and its failure mode was analyzed.Then,the mechanical properties of spandex reinforced epoxy shape memory composites and pure epoxy shape memory composites were compared by DMA experiment,uniaxial tensile test,bending test,fracture test and vibration experiment.It was found that the addition of volume fraction of 1.92% spandex.The tensile modulus and tensile strength of the composites decreased by 6.6% and 6.8%,respectively,the elongation at break and the stress and strain curve were respectively An increase of 20.00% and 16.48%;bending modulus increased by 23.08%;plane strain fracture toughness increased by 16.9%.Relative to the reduced tensile modulus and tensile strength,the elongation at break,the stress-strain curve area,the flexural modulus,and the plane strain fracture toughness.Next,uniaxial tensile tests were simulated by Abaqus finite element analysis software,and vibration experiments were also simulated by Patran/Nastran finite element analysis software.The results can fit with experiment results.Finally,by Python script,using Abaqus and genetic algorithm,the spandex fiber laying position was optimized.The maximum stress corresponding to the position of the optimized spandex was 54 times smaller than before,which provides guide to lay spandex fibers.