Crack propagation under constant amplitude loading based on an energetic parameters and fractographic analysis

Structural failure assessment approaches take into account local parameters, specimen geometry, loading and material. In the case of welded joints, in addition to these parameters, consideration must be given to the effect of the heterogeneity of properties due to welding. The objective of our work is to study the fatigue crack propagation of welded joint in API X70 pipeline steel. This experimental study focused on welded joints in the different parts, base metal, weld metal and heat affected zone. The concepts of fracture mechanics are used to analyze the harmfulness of defects in welded joints and the main part of fatigue life falls on the crack propagation. The results obtained show that the fatigue crack propagation rate of cracks in the heat affected zone is delayed compared to the other zones. The effect of the microstructure and the quality of submerged arc welding of the studied X70 steel are significant. Tensile tests, hardness and measurement of energetically parameters complemented this work.

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“…11. (Crack opening load Pop was measured at the beginning of the horizontal segment on δ' with respect to P diagram [54]. Fig.…”

Section: Evolution Of Energy Parametersmentioning

confidence: 99%

Fatigue crack propagation in welded joints X70

Deliou

Bouchouicha

2018

Frattura Ed Integrità Strutturale

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“…The values of parameters 𝐶, 𝑑, and 𝑚, obtained by means of the optimization procedure, are 8.4810 -17 , 2.12, and 3.27, respectively. Importantly, the value derived for 𝑚 falls in the range between 3 and 4 commonly observed for aluminium alloys (Benguediab et al, 2012;Paris & Erdogan, 1963;Sasaki et al, 2008).…”

Section: The Modelmentioning

confidence: 65%

“…The process of crack growth under cyclic loading can in general be divided into three phases: crack initiation, crack propagation, and structural fracture, as schematically illustrated in Fig. 3 (Benguediab et al, 2012). The first stage presents a threshold below which there is no crack growth.…”

Section: The Modelmentioning

confidence: 99%

Simple Hybrid Model for Estimating Remaining Useful Life of SiC MOSFETs in Power Cycling Experiments

Eng,

Lövberg,

Misiorny

et al. 2023

PHMAP_CONF

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Recording and prediction of the accumulated damage, which will eventually lead to the failure of power electronic modules, is an aspect of high importance for power electronic systems design and, in particular, for development of Prognostic and Health Management (PHM) schemes for in-field applications. To this end, this paper presents a simple and cost-effective prognostic method for predicting the remaining useful life (RUL) of TO-247 packaged silicon carbide (SiC) metal-oxide semiconductor field-effect transistors (MOSFETs) subjected to power cycling experiments. The model assumes that the major failure mode is bond-wire lift-off and uses a damage accumulation scheme based on Paris’ crack law. The only inputs to the model are historical data on the average junction temperature swing and the temperature-compensated drain-source ON-state resistance at the peak temperature of the current cycle. Using only these two input values, the model is shown to predict RUL with surprising accuracy for the range of constant current loads determining cycling conditions under which the test data series have been acquired. This work is a first step in an ongoing project towards building more elaborate prognostic schemes for RUL-determination of SiC power MOSFETs in actual working conditions, using physics-informed neural networks (PINNs).

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