Overview of Small Punch Test

Small Punch Test (SPT) is an evolving small specimen test technique which has the potential to extract the mechanical properties from small volume specimens. This test method is used to determine the in situ mechanical properties of components in service for measuring the structural integrity and residual life. The pre-requisite for using this test is to establish correlations between SPT and conventional tests in priori. A number of correlations have been developed between traditional tests and SPT results for determining mechanical properties. The validity of these correlations have to be examined, as these are developed from a specified set of materials and testing conditions. To evaluate SPT and the developed correlations, it is crucial to understand the fundamentals of this test method, the different regimes of deformation experienced by the specimen and its sensitivity for various testing parameters. The attempt of this work is to relook the SPT as a whole and its potential to measure the different mechanical properties. This work lists the various SPT configurations, materials used in literature and the correlations developed. In addition, the influence of test parameters on SPT response, the viability of empirical or analytical relations used to extract mechanical properties and the general issues in SPT is discussed.

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