聚合物PA66直至断裂的全程单轴本构关系研究

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

基于有限元辅助测试方法(Finite element aided testing,FAT)对新型聚合物PA66开展了直至破坏的全程单轴本构关系的研究。另外,将VIC-3D光测所得的试样表面应变场结果与有限元模拟结果进行对比,表明通过FAT方法获得的聚合物PA66全程单轴本构关系结果准确有效。最后给出了聚合物PA66的全程单轴本构关系曲线,给出了对应Chaboche本构关系模型的参数、材料临界破断应力、破断应变、应力三轴度等,并对试样的破断机理进行了分析。

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 ele-ment 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,criti-cal breaking strain,stress triaxiality of polymer material PA66 are obtained,and also the fracture behavior of those specimens were dis-cussed.