A statistical method for rapid determination of endurance limit based on a thermographic method

The staircase method is traditionally employed to estimate the endurance limit, requiring to test of a relatively large number of specimens at several load levels to obtain a reliable dataset, making this procedure time-consuming and expensive. A rapid method, based on thermography is alternatively employed to estimate the endurance limit, intended as the fatigue strength at 1 or 2 million cycles. The procedure results in a relation between the stabilized temperature as a function of the maximum applied stress or amplitude and involves manual processing of the data to determine the endurance limit. The present paper presents a statistical model based on the Maximum Likelihood Method to estimate the endurance limit by the aforementioned thermographic method, which is automatic, and does not involve manual manipulation of the dataset.