Quantitative thermographic method for fatigue life prediction under variable amplitude loading

Abstract

Quantitative thermographic methodology (QTM), which takes energy dissipation as a fatigue indicator, has been successfully applied to predict the fatigue life of materials and welded joints under constant amplitude loading. This study advances the QTM approach for predicting the fatigue life under variable amplitude loading in both low and high cycle fatigue regimes. Experimental data, obtained by fatigue tests under variable amplitude loading, were used in order to apply the developed QTM approach and to demonstrate that it is able to take into account the loading sequence effect. Good predictions of the fatigue life were achieved.

Thermo‐based fatigue life prediction: A review

“…Drawing inspiration from Wang's work, this fatigue life prediction approach can be extended to materials that exhibit a temperature decrease in phase II, such as the AZ31B magnesium alloy 59 Variable amplitude loadings By incorporating the concept of cumulative fatigue damage, Feng et al 60 enhanced the quantitative thermographic method to predict the fatigue life under variable amplitude loadings, including two‐step, repeating two‐step, and periodical‐over loadings. The energy‐based model that has been developed employs an exponential format to depict the progression of nonlinear fatigue damage.…”

Review of Fatigue Assessment Approaches for Welded Marine Joints and Structures

“…As reported in [117], the thermal methods [118][119][120][121][122][123][124][125][126][127], which are based on the detection of the self-heating effect of the metallic materials subjected to fatigue loading using the thermographic technique, can be classified into several categories.…”

“…As reported above, the real structures are subjected to VA fatigue loads, so the quantitative thermographic method (QTM) [53] was developed in [117]. Then it can be applied to marine and offshore structures, which are subjected to VA fatigue loads during their service lives.…”

Experimental study of the strengthening effect: A novel fatigue life prediction method for variable amplitude loads

“…[1][2][3][4] It is important to consider the load interaction in life prediction under variable amplitude loads, and many cumulative damage models have been developed. [5][6][7][8][9][10][11] Depending on the relationship between fatigue damage and cycle life fraction, existing cumulative damage models were divided into linear and nonlinear models. The Palmgren-Miner rule 12 is the earliest linear cumulative damage model, widely used due to its simplicity.…”