DEFORMATION AND FRACTURE OF FIBERS Part 4:Fracture Behaviour of PET and PAN Fibers in Tension

The dynamic observation of the fracture processes of PET(polyethylene terephthalate)andPAN(polyacrylonitrile)fibers in tension was carried out under a scanning electron microscope.Thestepwisc micrographs taken revealed the features of crack initiation and crack growth and of thefailure of the fibers.The fracture behaviour of PET fibers in tension is characterized by theoccurence of shear bands,which initiate a crack whose development leads to the final failure of afiber.For tensile PAN fibers,a high concentration of cracks are initiate in the skin of a fiber,andthen a few or one of them develop themselves by way of pulse and lead to the final failure of the fi-ber.

DEFORMATION AND FRACTURE OF FIBERS Part 4:Fracture Behaviour of PET and PAN Fibers in Tension

The dynamic observation of the fracture processes of PET(polyethylene terephthalate)and PAN(polyacrylonitrile)fibers in tension was carried out under a scanning electron microscope.The stepwisc micrographs taken revealed the features of crack initiation and crack growth and of the failure of the fibers.The fracture behaviour of PET fibers in tension is characterized by the occurence of shear bands,which initiate a crack whose development leads to the final failure of a fiber.For tensile PAN fibers,a high concentration of cracks are initiate in the skin of a fiber,and then a few or one of them develop themselves by way of pulse and lead to the final failure of the fi- ber.