A Miniaturized Thin-Plate Low Cycle Fatigue Test Method at Elevated Temperature

Abstract

This study aims to develop a high temperature LCF test method using a non-standard miniature thin-plate (MTP) specimen in order to characterize cyclic visco-plasticity behavior of component materials. For demonstration, fully reversed strain-range controlled LCF and creep-fatigue (CF) tests at 600 °C have been performed for a martensitic steel using both standard-sized full-scale (SSFS) and MTP specimens. A scaling factor is determined using cyclic visco-plastic finite element (FE) for geometry constraint evaluation and data conversion based on the reference strain approach. The equivalent energy principal is proposed to assess the geometry constraint effect that non-standard MTP specimen has. The high temperature LCF results from the MTP specimen based on the proposed testing methodology have shown a good agreement with SSFS specimen data under equivalent conditions. The methodology can therefore be used to conduct accurate transferability to achieve equivalent LCF behavior between the conventional standard specimen and the MTP specimen.