Creep life analysis by an energy model of small punch creep test

Currently most creep life prediction methods by small punch test are focused on the steady creep deformation phase which is similar to conventional uniaxial creep tests. This paper presents a novel creep life extrapolation approach by small punch creep test. An energy model believed to have advantages in modeling creep deformation process of small punch tests is introduced. Linear expression between general strain and creep deflection was recommended as the deformation criterion in the analytical prediction. Meanwhile, the combination of ball radius and hole size of the lower die was analyzed to accommodate the difference of experimental devices. Based on the small punch creep data with different materials and creep environments, the creep life in the multiaxial form of large deformation was analyzed. Finally, by selecting different creep displacements from initial creep phase, the results were in agreement with the expected trend. The creep life extrapolation method was verified. (C) 2015 Elsevier Ltd. All rights reserved.