A B S T R A C T The application of small specimen creep test techniques in the evaluation of creep properties of materials in-service has been increasing. To obtain the creep data accurately and conveniently, a new creep test method with small cantilever beam specimens is proposed. Analytical equations are derived that can convert the load to equivalent uniaxial stress and the displacement rate to equivalent uniaxial strain rate. Three types of the cantilever beam specimens are designed. The optimal configuration of the cantilever beam specimens is recommended with the aid of finite element method, which is further validated by the cantilever beam and uniaxial specimen tests. The results show that parameters obtained from the cantilever beam tests correspond reasonably well with those from uniaxial tests at low stress levels. With a relatively large equivalent gauge length, the cantilever beam specimen allows the small creep strain rate data obtained with a high accuracy.Keywords creep properties; cantilever beam specimen; small specimen test; finite element method. N O M E N C L A T U R EB, n = Norton's power law creep constants E, ν = elastic modulus and Poisson ratio, respectively d, d ss = load-point displacement and steady-state load-point displacement rate, respectively l, b, h = distance from the fixed-point to the load-point, specimen width and specimen height, respectively M, P = bending moment and applied load, respectively r = radius of the cylindrical punch κ = curvature radius of the specimen σ u,eq ,˙ε ss;eq = equivalent uniaxial stress and equivalent steady-state strain rate, respectively I N T R O D U C T I O NThe evaluation of creep properties of materials is essential to ensure the safe operation of in-service components at high temperature. 1 In general, creep properties are experimentally determined by using standard tensile creep testing specimens, which requires a sufficient volume of bulk materials. However, it is difficult to manufacture a standard specimen from the in-service components due to the limited material available. 2-6 For some special structures, it may be impossible to obtain sufficient materials for a standard specimen, for instance, the welded structures 7 and thin plate structures. 8-10 Small specimen creep testing techniques have therefore been developed, including the conventional sub-size specimen, the small punch, impression and small ring (SR) specimens. 11,12 Some recent researches, however, have indicated that the small specimen creep testing should be carefully carried out to achieve a reasonable measuring accuracy. The small punch tests have been well used to characterize creep properties of materials. 13-17 But the current correlations between small punch test and the corresponding uniaxial creep test are rather empirical. [18][19][20][21][22][23][24] It is difficult to describe the stretch forming process that produces a bulge in the thin specimen and results in its high complexity and nonlinearity. 25 The results of small punch tests are adversely affected by th...
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