Three-dimensional Fatigue Research Articles

Evaluation of the psychometric properties of the English MisoQuest and its relationship with audiological and psychological factors

Objective The aim was to establish the validity and reliability of the English version of MisoQuest, a 14-item misophonia questionnaire initially validated in the Polish language. Design Reliability was examined through internal consistency, measurement error, and test-retest reliability. Validity was evaluated with confirmatory factor analysis, convergent, and discriminant validity. Participants completed the English MisoQuest at two-time points and participated in follow-up interviews. Study Sample The study included 451 adult participants, with an average age of 36.4 years (SD = 12.8). Results The English MisoQuest showed very good internal consistency (α and ω = 0.93) and high test-retest reliability (ICC = 0.89). While CFA indicated adequate overall model fit, it did not fully support a one-factor structure, as some items shared variance even when controlled for the latent variable. Convergent validity was demonstrated by moderate to strong correlations with established misophonia questionnaires. Weak correlations with non-misophonia measures supported discriminant validity. Unexpectedly, moderate correlations were found with Hyperacusis Impact Questionnaire (r = 0.34; p < 0.01) and Three-dimensional Fatigue Inventory (r = 0.31; p < 0.01). Conclusion The study found that the English version of MisoQuest is a reliable and valid tool for measuring misophonia within the English-speaking adult population.

Three-dimensional fatigue crack initiation and propagation behavior of stress-corroded steel wires for bridge cables

Three-dimensional fatigue crack initiation and propagation behavior of stress-corroded steel wires for bridge cables

Analysis of tooth root three-dimensional fatigue crack initiation, propagation, and fatigue life for spur gear transmission

Analysis of tooth root three-dimensional fatigue crack initiation, propagation, and fatigue life for spur gear transmission

Study on fatigue damage and frequency attenuation characteristics of carbon fiber composite

Fatigue analysis and life prediction are the key and challenging issues in the mechanics research of composite material. In this paper, based on the progressive damage analysis method and fatigue cumulative damage theory, a three-dimensional fatigue cumulative damage numerical model is constructed by introducing the orthotropic constitutive equation, 3D-Hashin fatigue criterion, and material performance degradation scheme. Two loading conditions of tension–tension fatigue and compression–compression fatigue of Carbon Fiber composite laminates were investigated. In the tension–tension fatigue experiments, when the cycle is [Formula: see text] times, the experiment and the numerical simulation all not completely destroyed. However, progressive degradation of stiffness and strength was observed in certain elements, accompanied by some internal damage. On the other hand, the experimental and predicted values for compression–compression fatigue were within a triple error band. Then the cumulative damage evolution law of each laminate under fatigue load was analyzed. Compression–compression fatigue damage initiated from the center of the hole and expanded to both sides of the composite laminate, and its fatigue life increased with the increase of the compression–compression fatigue load. Considering the degradation of stiffness in composite materials under fatigue loading, which leads to frequency attenuation in the structure, this paper established a connection between the fatigue state and frequency to obtain the frequency attenuation curve under fatigue loading. The relationship between frequency and fatigue life was revealed, allowing for the prediction of remaining fatigue life in practical engineering based on the rate of inherent frequency reduction.

Three-dimensional fatigue crack quantification using densely connected convolutional network-assisted ultrasonic guided waves

Three-dimensional fatigue crack quantification using densely connected convolutional network-assisted ultrasonic guided waves

Fatigue Crack Propagation of Corroded High-Strength Steel Wires Using the XFEM and the EIFS

A fatigue test and numerical simulation on corroded high-strength steel wires with multiple corrosion pits were conducted. A new approach combining the eXtended Finite Element Method (XFEM) and the Equivalent Initial Flaw Size (EIFS) was proposed to investigate three-dimensional fatigue crack growth and life prediction. The EIFS values for the steel wires were determined under various stress ranges and corrosion pit conditions. The fatigue crack propagation path, the fatigue life, and the stress variation under different pit types and depths were investigated. The results reveal a significant linear relationship between the maximum principal stress range and the fatigue life in logarithmic coordinates for steel wires with various pit types. Additionally, the EIFS is found to be dependent on the stress range and the pit depth. All the predicted outcomes fall within a range of twice the margin of error. The accuracy of this novel method is further verified by comparing predicted results with the test data. This research contributes to a better understanding of the fatigue performance of corroded high-strength steel wires and can assist in the design and maintenance of notched components.

Three-dimensional fatigue crack growth based method for fatigue reliability of metallic materials

Three-dimensional fatigue crack growth based method for fatigue reliability of metallic materials

Three-dimensional high-resolution crystallographic observation of the entire volume of microstructurally small fatigue cracks in Ni-Co based superalloy

The crystallographic features of microstructurally small fatigue cracks (MSFCs) in a Ni-Co-based superalloy were analyzed by using a Xe plasma focused ion beam scanning electron microscope (PFIB-SEM) system in conjunction with electron backscatter diffraction (EBSD) analysis. The crystallographic orientation of the three-dimensional (3D) fatigue crack growth path was successfully observed using a large-volume, high-resolution 3D image. The major parts of the crack surface were close to the {111} slip plane. Our results indicated that the Mode II fatigue crack growth mechanism is locally more predominant than the general blunting-resharpening Mode I fatigue crack growth mechanism, not only in the Stage I region but also in the larger part of the Stage II region of MSFC growth process.

Three-dimensional fatigue crack growth prediction method based on consistency retention

• A 3D crack growth update method considering load sequence effect based on XFEM is proposed. • The consistency retention strategy for crack growth life and path is proposed. • A framework for 3D fatigue crack growth based on consistency retention is built. • From 2D crack growth to 3D crack growth, the effectiveness of the proposed method is verified. • The proposed method can achieve dynamic following and accurate prediction of 3D fatigue crack growth. To reduce the influence of uncertain factors, a three-dimensional fatigue crack growth prediction method based on consistency maintenance is proposed. Firstly, the crack growth update under complex loads is realized based on XFEM. Subsequently, the life correction method based on the improved particle filter and the path correction method based on the improved maximum tangential stress criterion are proposed. Taking real crack data as input, the accuracy of prediction results is improved from two dimensions of life and path. Finally, five cases are used to verify the proposed framework, which proves that it can realize dynamic tracking of crack growth.

An X-FEM based framework for 3D fatigue crack growth using a B-spline crack geometry description

This paper presents an X-FEM based iterative framework for numerical simulation of three-dimensional fatigue crack propagation. To accurately describe the crack geometry, B-spline curves and surfaces are used for the crack front and faces respectively. A new crack front extension method based on the Möller–Trumbore algorithm is introduced to achieve fully automated crack growth for complex geometries. To validate the presented work, three different cases are discussed: (1) compact tension specimens with an asymmetrically located hole, (2) a beam with a slanted crack subjected to a three-point bending load and (3) a beam with a slanted crack subjected to a torsion load. Good agreement between the numerical and experimental results is observed.

3-Dimentional Elucidation of Fatigue Characteristics and Fracture Morphologies in Spot Welding Joints of High Strength Steel

In order to investigate the three-dimensional fatigue properties of resistance spot welded joints made of high strength steel, this study was carried out observed three-dimensional fatigue cracks and calculated stress intensity factors using fem analysis. In addition, this study was conducted under shear mode and pure shear mode to investigate the influence of loading mode during fatigue testing. As a result, it was found that a new crack growth behavior branched in the welding circumferential and width direction under the low loading force range. However, all the cracks leading to final fracture were of the same type, and it was confirmed that the fatigue strength was not affected by a new crack growth behavior. Moreover, the results of observed initial fatigue crack growth angles and the calculated stress intensity factor, KIθ, were in close agreement, which proved that the fatigue crack growth behavior was strongly influenced by the fracture mechanics.

Three-dimensional fatigue crack propagation by means of first order SIF approximation

In this paper we make use of a closed-form solution for mode I Stress Intensity Factors (SIF) in three-dimensional planar flaws based on homotopy transformations of a disc. The utilised equations are very accurate when the flaw is a small deviation from a circle. Under the hypothesis of an isolated crack, the SIF at each point of the crack border is calculated to assess the crack shape after propagation. The solution is proposed in terms of the Fourier series and the crack growth rate equation is taken according to Paris’ low. Many examples are proposed with the aim of predicting the final shape of different types of embedded planar flaws in butt welded joints under fatigue tensile loading.

Three-Dimensional analysis of mixed mode Compact-Tension-Shear (CTS) Specimens: Stress intensity Factors, T-stresses and crack initiation angles

• Extensive three-dimensional (3D) finite element analyses are carried out for mixed mode Compact-Tension-Shear (CTS) specimens. • In-plane and out-of-plane geometric dimensions with varying crack depths ratios and thicknesses ratios are considered under different loading angles. • Distributions of mixed mode stress intensity factors and T-stresses along the crack front are obtained. • The combined effects of geometric dimensions and loading angles on crack front field charactering parameters have been illustrated. • Solutions are used to predict the crack initiation angles based on several mixed-mode fracture criteria including MTS, GMTS, SED and GSED. In order to characterize the crack tip stress field in three-dimensional fatigue and fracture problems, stress intensity factor and T -stress solutions are usually necessary. In this paper, extensive three-dimensional (3D) finite element models are constructed for Compact-Tension-Shear (CTS) specimen, which is one of the most widely used specimens for fatigue and fracture tests under mixed-mode I&II loading. In-plane and out-of-plane geometric dimensions including varying crack depths ratios ( a / W = 0.3, 0.5 and 0.7) and thicknesses ratios ( B / W = 0.1, 0.3 and 0.5) are considered under different loading angles ( β = 0°, 15°, 30°, 45°, 60°, 75° and 90°). The results of stress intensity factors ( K I , K II and K III ) and T -stresses ( T 11 and T 33 ) along the crack front are computed and analyzed. The combined effects of geometric dimensions and loading angles on these fracture parameters have been illustrated. The solutions of the parameters are then described using empirical formulae by fitting numerical results with the least-squares method. Solutions obtained have been used to predict the crack initiation angles for CTS specimens based on mixed-mode fracture criteria including the maximum tangential stress (MTS) criterion, the generalized MTS (GMTS) criterion, the strain energy density (SED) criterion and the generalized SED (GSED) criterion. Solutions are useful for fracture and fatigue problems of mixed-mode I&II, such as analysis of the constraint effects on fracture toughness and propagation path of fatigue crack.

A compatible regression Weibull model for the description of the three-dimensional fatigue [formula omitted] field as a basis for cumulative damage approach

Different considerations suggest that the fatigue crack growth mechanism, in particular, the threshold between propagating and non-propagating conditions is factually governed by maximum stress rather than stress range values. This propitiates the consideration of σ M , as the primary variable to which the S–N field should be referred to whereas R = σ m / σ M would act as a secondary variable. Based on physical and statistical principles, notably the compatibility condition between both distributions F ( N ; σ M , R ) and F ( σ M ; N , R ) , a functional equation is established whose solution provided the analytical expression of the σ M – N – R field representing the more general solution of the S–N field characterized by the common fatigue endurance limit. Higher reliability in the model S–N assessment is achieved because of the pooling of all results irrespective of the R -value. The essential point is that the normalizing variable V derived from the σ M – N – R field for certain load history can be identified as a state of cumulative damage and as such related to the probability of failure. The validity of the new model is confirmed by its application to data from experimental campaigns performed on AlMgSi 1 and Inconel 718 alloys. • A three-dimensional S–N model, including σ M as driving force, is proposed and the R-ratio effect. • The model allows different pairs of σ M -R results to be jointly assessed as a unique sample. • Damage life prediction for any load is predicted from the univariate single normalized variable V. • Application to different metallic materials provides satisfactory definition of the 3D S–N field.

Stress-strain state analysis and fatigue prediction of D16T alloy in the stress concentration zone under combined tension-torsion load

Engineering machines and components are proneto structural failures during their service time due to certaintechnical reasons and also due to some unforeseencircumstances. The technical breakdowns sometime lead tohigh economic imbalance and can also be fatal to life andproperty. Predicting the failure and evaluating the breakagecharacteristics of engineering components are crucial indetermining the life of the component and also increasetheir maintenance and safety in daily life. This research study deals with the modelling andnumerical simulations of an aluminium alloy specimen in3D stress-state and thereby predicting the fatigue failure ofthe material subjected to external cyclic loadings. Topredict the failure of a component, a specimen with aninduced crack can be evaluated through cyclic loadingprocess. It is based on the fact that the presence of a crackstends to modify the stresses present locally on thecomponent that the elastic deformation and the stressesattributed with them are totally insufficient for the designagainst fracture. It is based on the assumption that thespecimen undergoes complete fracture when the crackreaches its critical size even though the stress at the criticalcrack tip is much lower than the yield stress of thecomponent. The critical size of the crack is based on theapplication of the load and the number of load cycles itundergoes.The main aim of this research is to present andvalidate the numerical method for the study of theinfluence of cracks present in the engineering components.Finite element method was applied for numericalsimulation. In this study the tension, torsion, combined&#x0D; tension-torsion and fatigue loads was applied. Theexperimental testing data of mechanical properties wasused in numerical simulation as input data. This researchstudy investigates the three-dimensional stress-strain stateand fatigue prediction of D16T aluminium alloy which ispredominantly used in the aerospace and automobileindustries for their high strength-to-weight ratio and muchbetter physical properties. The different specimen modelsare then analysed and the most efficient one was selectedfor the preliminary experimental tests.

Hubungan Fatigue dengan Kejadian Excessive Daytime Sleepiness pada Perawat

Nurses hold an important responsibility for maintaining patients’safety. It has been known that fatigue and sleepiness may result in errors with negative consequences for patient safety. The purpose of this study was to examine the relationship between fatigue and excessive daytime sleepiness among nurses. This research design is descriptive correlation. The total sample in this study was 36 nurses. This research was conducted at the Special Eye Hospital Medan. Sampling using purposive sampling. Data collection using the Three-Dimensional Work Fatigue Inventory (3D-WFI) and The Epworth Sleepiness Scale. Data analysis using the Chi-Square test. The results of this study indicate that the majority of nurses experience tired fatigue as many as 22 respondents (61.1%) compared to 14 respondents (38.9%) not tired. Chi Square test showed an association between fatigue and excessive daytime sleepiness (EDS) in nurses (P = 0.000 &lt;α 0.05). This study recommends nurses to optimize the work hours of nurses to overcome daytime sleepiness, and for nurses to maintain conditions in order to avoid excessive sleepiness which can cause adverse event.

Failure Analysis of a Working Roll Under the Influence of the Stress Field Due to Hot Rolling Process

Crack growth leads to roller failure and damages other parts. The three-dimensional modeling of crack growth, the effect of different factors on the fatigue life of roller, and the effect of stress distribution are important factors that should be considered. The purpose of this paper is to investigate the failure and modeling of three-dimensional fatigue crack growth and fatigue life prediction of high chromium steel (HCS) rollers in hot rolling to minimize the failure of rollers by practical solutions. This article uses boundary element method for fatigue crack growth under the influence of stress field. The proposed method allows modeling each of the components involved separately in the contact area. As a result, this method is faster than finite element models with contact components. In this regard, the types and causes of cracks in the roller are analyzed with the effect of residual stresses on the roller. By selecting the HCS roller and sheet, modeling and stress analysis are performed by finite element method. This study includes the effect of crack growth factors such as load ratio, length, and initial crack angle. The results of the numerical model showed a good agreement with the results obtained in the field observations.

Three-dimensional fatigue crack propagation analysis of welded steel beam based on global-local numerical model

The existing fatigue assessment approaches were mainly conducted on the component level. The interaction of local component damage and the global response cannot be well addressed. In this study, three-dimensional (3D) fatigue crack propagation analysis approach based on global-local numerical model was implemented, and examined to be accurate and effective through a series of systematic experimental data obtained by Fisher. Afterwards, the approach was introduced into a typical steel truss bridge for realizing more refined fatigue assessment from the global structural level. The fatigue performance of the longitudinal steel welded beam in the steel truss bridge was investigated based on global-local model and local model respectively. It was found that there is no difference in terms of the fatigue crack growth mechanism between the simulation between global-local model and local model due to that the stress level of the whole structure is relatively low. At last, the effect of heavy haul train operation on the fatigue performance of the steel truss bridge was analyzed. It was observed that the residual life of the longitudinal steel welded beam would have an obvious reduction when the axle load was increasing. The research work in this study presents a technical solution for the fatigue assessment of the global structure and can provide beneficial reference for relevant practical engineering projects.

Model-driven fatigue crack characterization and growth prediction: A two-step, 3-D fatigue damage modeling framework for structural health monitoring

Prevailing fatigue damage evaluation approaches that make use of the acoustic nonlinearity of guided ultrasonic waves (GUWs) are sustained by simplified models, most of which depict three-dimensional (3-D) fatigue damage in a two-dimensional (2-D) domain [1]. Such approximation risks the evaluation accuracy. With such motivation, this study aspires to a new, two-step modeling framework, aimed at accurately characterizing and continuously monitoring fatigue damage, from its embryonic initiation, through progressive growth to formation of macroscopic crack. In the first step, a 3-D, analytical model based on the theory of elastodynamics sheds light on the generation of contact acoustic nonlinearity in GUWs under the modulation of `breathing' behavior of a non-penetrating fatigue crack, on which basis a crack-area-dependent nonlinear damage index is yielded. In the second step, a 3-D fatigue crack growth model predicts the continuous growth of the identified fatigue crack in the length and depth along crack front. The framework is validated using numerical simulation, followed with experiment, in both of which the initiation and progressive growth of a real corner fatigue crack is monitored, with continuous prediction of the crack growth in length and depth. Results have demonstrated the accuracy and precision of the developed modeling framework for characterizing embryonic fatigue damage.

Three-dimensional fatigue crack propagation simulation using extended finite element methods for steel grades S355 and S690 considering mean stress effects

• The Walker equation is employed to consider the mean stress effects. • Stocastic analysis is conducted to obtain fatigue crack growth rate with 95%, 97.7%, and 99% guarantee. • A user-defined fatigue crack propagation subroutine was developed using phantom nodes-based extended finite element method (PN-XFEM) and Virtual Crack Closure Technique (VCCT). The assessment of fatigue crack propagation of steel structures is essential and important especially to improve the application of high strength steel in construction. The load ratio R, reflecting mean stress effects, will be changed with crack extension in the steel structures with complicated geometry. In this paper, the Walker equation is employed to fit the fatigue crack propagation rate of steel grades S355 and S690 based on experimental data in the literature to incorporate the mean stress effects. The material fatigue crack propagation parameters with 95%, 97.7%, and 99% guarantee of Walker equation were obtained by a stochastic analysis using the Monte Carlo method. The fatigue life was firstly predicted by the analytical method and was used as a baseline for numerical fatigue crack propagation simulation. A user-defined fatigue crack propagation subroutine based on the Walker equation was developed using phantom nodes-based extended finite element method (PN-XFEM) and Virtual Crack Closure Technique (VCCT) to consider the mean stress effects. The proposed three-dimensional fatigue crack propagation simulation subroutine is successfully validated of both steel grades, S355 and S690.