Full-range Uniaxial Constitutive Relationship up to Failure of Polymer PA66

  Polymers have been widely used in various structural engineering, and the importance of relevance to their fracture properties and full-range constitutive relationships up to failure is attached recently. The accurate full-range constitutive relationships up to failure are important for light structure design and safety assessment. Based on finite-element-analysis aided testing(FAT) method^[1], the full-range uniaxial constitutive relationship of PA66 is investigated. Meanwhile, the strain distribution field on the surface of funnel-shaped specimen is tested by the DIC (Digital image correlation) optical measurement system. Comparing the testing results with the finite element simulating results by FAT, both of them are coincided well. So it is accurate for FAT to obtain the full-range uniaxial constitutive relationship of PA66. As results, for PA66, the parameters of Chaboche constitutive relationship model, critical breaking stress, critical breaking strain, stress triaxiality of polymer material PA66 are obtained, and also the fracture behavior of those specimens were discussed.