Research On The Evaluation Of Material's Creep Properties By C-shape Ring Specimen With Fixed Constraint

In this paper,combing the advantages of three-point bending specimen with fixed constraints and small punch creep specimen,a new C-shape ring specimen with fixed constraints(CRSFC)was proposed.This new specimen has great advantages in the evaluation of material creep properties due to its small size and convenient process.Especially,it will not cause structural integrity damage for tubular components.First,the conversion relationship between CRSFC and uniaxial creep test data was established on the basis of beam bending model.Creep tests and error analysis were conducted.Then the application range of the above conversion relationship was investigated by finite element analysis.When specimen deformation enters into large deformation stage,the conversion relationship was established on the basis of rod tensile model.Meanwhile,creep tests were carried out.The following is some main works of this paper:(1)At the primary stage of deformation,specimen deformation satisfies beam bending model.The conversion relationship was established by theoretical analysis.Then the fix was designed to conduct creep tests.The results show that CRSFC can be well used to evaluate material creep parameters.(2)When the deformation is large,the assumptions of beam bending model may fail.Here the application range of the conversion relationship based on the beam bending model was investigated by critical displacement.The results show that beam bending model holds when specimen deformation is under critical displacement.Otherwise,the creep strain rate obtained by beam bending model will produce large deviation.(3)When specimen deformation enters into large deformation stage,the conversion relationship between CRSFC and uniaxial creep test data was established on the basis of rod tensile model.Creep test results show that rod tensile model can be well used at the large deformation stage of CRSFC.