The ultra-thin Ag interconnectors used for GaAs solar cell arrays applications face numerous challenges in deep space exploration missions, such as extreme temperature variations and the impact of wind and dust particles. In this study, finite element analysis was employed to investigate the effects of temperature cycling, as well as the impact of wind and dust particles. These analyses helped identify

Fatigue is an irreversible thermodynamic process accompanied by multi-component energy dissipation and entropy accumulation. This study analyzes the energy composition of total mechanical input hysteresis energy during the fatigue process of composites. By excluding thermal dissipation and viscoelastic internal friction dissipation energy, which do not directly contribute to fatigue damage, the irrecoverable

The characterisation of the very high cycle fatigue (VHCF) regime has become pertinent due to the interest of extending the service life of engineering structures. However, the fatigue testing of materials at the longer lives of VHCF regime (usually greater than 10 million of cycles) is by far most efficient with an ultrasonic fatigue testing system, which introduces new challenges such as the specimen’s

Brazing with nickel-based filler metals under vacuum is frequently applied for joining metals in applications that require high resistance to mechanical loads, corrosive environments and elevated temperatures. However, melting-point depressant elements in the filler can lead to brittle phases in the brazing seam, affecting crack initiation and propagation. This study investigated cylindrical butt joints

This work presents a framework that allows designers to accurately estimate the fatigue lifetime of injection molded short fiber reinforced parts. The framework and its calibration are demonstrated on a large set of experimental data, increasing the complexity in loading conditions, anisotropy, and stress state, and demonstrated on two demonstrator parts. By step-by-step increasing complexity in both

We conducted an in-depth investigation into the subsurface-initiated rolling contact fatigue failure of GCr15 bearing elements subjected to high-cycle loading, emphasizing the comprehensive understanding on the time-dependent microstructural evolutions mechanism with respect to the rolling element ball and inner/out raceway. To this end, a specialized experimental strategy was implemented, maintaining

Porosity significantly impacts the fatigue performance and stability of dual laser additively manufactured metallic materials. This study presents a comparative analysis of the fatigue behavior of samples fabricated by single-laser powder bed fusion (SL-PBF) and dual-laser PBF (DL-PBF). It shows that porosity defects in the overlap region reduced the fatigue strength of DL-PBF samples by nearly 20 %

Fretting fatigue (FF) involves multiaxial and non-proportional stress states in addition to strong stress gradients, making crack propagation modeling challenging. In this work, we evaluate different models based on stress intensity factors (SIFs) to predict crack propagation kink angles under FF conditions, including both theoretical and artificial neural network (ANN) models. To train and test the

This study systematically examines the fretting fatigue behavior of Ti-6Al-4 V dovetail joints with and without shot-peening (SP) treatment, focusing on crack initiation, propagation mechanisms, and SP-induced microstructural modifications. An innovative four-camera in situ observation system was developed to track real-time crack evolution at four critical locations of the dovetail tenon. Integrated

This study conducts low-cycle fatigue tests on an extruded magnesium alloy cabin. The relationship between the microstructure and macroscopic cyclic-deformation behavior was established by regulating the microstructure of the different precipitated phases. The results show that only the β’ phase is precipitated in the 200AT sample, and lamellar Long-Period Stacking Ordered (LPSO) phase and β’ phase

A reliability analysis method for predicting the service life of aircraft structures considering corrosion damage has been proposed. This method introduces corrosion damage as the initial damage into the Chaboche fatigue cumulative damage model, and uses Monte Carlo method to simulate and reconstruct the corrosion fatigue damage process of the structure, achieving reliability analysis of the corrosion

Surface roughness is a critical factor influencing the fatigue life of structural components. Its effect is commonly quantified using a correction coefficient known as the surface factor. In this paper, a phase field based numerical framework is proposed to estimate the surface factor while accounting for the stochastic nature of surface roughness. The model is validated against existing experimental

Based on stress-controlled fatigue tests of 45 carbon steel notched specimens, an in-situ comprehensive evaluation of fatigue damage evolution was accomplished via micromagnetic non-destructive testing techniques, and various magnetic parameters were then determined to describe the actual fatigue state. In general, the characteristics quantities extracted from magnetic hysteresis, Barkhausen noise

The very-high-cycle fatigue (VHCF) behavior of material BG2532, used in oil and gas completion strings, was investigated under both non-corrosive and hydrogen sulfide (H2S) gas corrosion conditions. During the experiment, the material’s fatigue property and fatigue fracture characteristics were studied. Additionally, the microstructure on the axial cross-section, perpendicular to the fatigue fracture

Fretting generates surface damage at the contact interface of components under pressure subjected to small-magnitude, relative oscillatory motion. In the presence of bulk cyclic loading, fretting fatigue occurs, significantly reducing the lifetime of affected components, such as the dovetail joint connections in turbine blades. In this research, the fretting fatigue response of additively manufactured

Variations of residual stress fields in a fatigue test specimen and/or across specimens influence the fatigue crack growth rate measurements. Therefore, these variations can contribute significantly to the scatter of fatigue properties obtained on specimens, such as additively manufactured specimens without stress relief, specifically at low stress intensity factor range. To address this problem, a

Investigations of the fatigue performance of adhesively bonded joints were initiated since the 1950 s. An abundance of publications has emerged dealing with the experimental investigation of the fatigue performance of adhesively bonded joints of various geometries and material combinations to serve the needs of various structures operating under various loading and environmental conditions. This work

This study develops a coupled corrosion-fatigue phase-field model to investigate the pitting-to-crack transition in high-strength steel wires by integrating chemical–electrochemical processes and cyclic loading effects within a unified computational framework. The corrosion-fatigue life (CFL) of high-strength steel wires was determined through coupled corrosion-fatigue experiments, and the phase-field

A full-range fatigue life prediction model based on a hybrid physics-informed and data-driven model (HPDM) specifically for the deck-rib welds of orthotropic steel decks (OSDs) is proposed. A physical information framework was established, which considers the effective notch stress concentration factors caused by weld geometry, different mean stress correction models, and welding residual stresses

With the increasing usage of thermoplastic composites, ultrasonic welding has become a critical joining technique owing to its superior performance. However, due to the heterogeneity of the welded joint, the damage evolution mechanism is complex and hard to predict its fatigue performance. In this paper, the fatigue damage evolution behavior of CF/PEEK ultrasonic welded joints is systematically investigated

The refined structure design of the single crystal (SX) turbine blades through the thin-walled coupled film cooling hole (FCH) improves the cooling efficiency. Frequent take-off and landing cycles of aircraft create a build-up of thermal stresses that can lead to thermal fatigue cracks around FCHs of thin-walled turbine blades. Due to the lack of systematic research on the thermal fatigue behavior

This study investigates and compares the static and fatigue performance of double-lap joint repairs applied to primary thin aircraft structures assembled using traditional fastening, pure bonding, and hybrid methods. Baseline configurations, representing optimally assembled joints with inherent designed strength, were compared to configurations with simulated defects, designed to replicate practical

This study investigates the transient fatigue crack growth (FCG) behaviour of AlSi10Mg aluminium alloy specimens produced by laser powder bed fusion and subjected to different post-processing treatments, including as-built, as-built shot-peened, stress-relieved, and stress-relieved shot-peened conditions. FCG tests were performed under constant amplitude (R = 0.05) and single tensile overload conditions

The structural components of a moving vehicle are subjected to non-stationary multi-directional excitations from irregular road profiles. Multiaxial fatigue analysis under non-stationary dynamic excitations plays a crucial role in accurately predicting the fatigue life of automotive components. A time-domain method for multiaxial fatigue analysis of automotive components under non-stationary loads

The design of jacket structures in offshore wind turbines (OWTs) is driven by fatigue, crucial due to dynamic loads from operational movements, waves, and wind. This study aims to develop a digital framework for fatigue analysis of tubular welded joints in jacket OWT, incorporating real 3D scanned geometries and imperfections through their digital images. Numerical analysis has been conducted using

The numerous advantages of the Selective Laser Melting (SLM) technology have made it a quite common Additive Manufacturing (AM) process for components made in metals and metallic alloys. Several factors, like building direction, defects, residual stresses and corrosion can substantially jeopardize the performance of the finished products obtained with such manufacturing process. In this regard, the

In this study, fretting fatigue tests were performed on dovetail assemblies. The displacement and strain of the components during testing were recorded using Digital Image Correlation (DIC) equipment. The results revealed that the dovetail assembly gradually exhibited a sticking phenomenon, stabilizing after approximately 10,000 cycles, with relative slip significantly reduced compared to the initial

Fatigue Indicator Parameters (FIPs), derived from cyclic intragranular and intergranular mechanical variables using the Crystal Plasticity Finite Element Method (CPFEM), can serve as surrogate measures of the driving force for fatigue crack formation within the first grain or nucleant phase. Simulating larger sample (i.e., increasing the number of grains) using CPFEM generally result in higher maximum

This study investigates the rolling contact fatigue (RCF) behavior of ductile iron (DI) using experimental and analytical method. The fatigue behavior of DI was assessed under both torsion fatigue and RCF. The RCF of DI was assessed by a 3 ball-on-rod test rig at a peak pressure of 3.6 GPa. Torsion fatigue tests were performed using an MTS test setup to determine the material’s stress-life (S-N) response

This study employs a cutting-edge process known as laser-assisted ultrasonic nanocrystal surface modification (LA-UNSM) to form a surface composite gradient deformation layer on A100 ultra-high strength steel to harmonize its corrosion and fatigue characteristics. The results revealed that the innovative method softened the sample surface via laser preheating, while the ultrasonic impact forged a composite

A new statistical technique is proposed to quantify the experimental uncertainty observed during ultrasonic fatigue testing of metals and its propagation into the stress-lifetime predictive curve. Hierarchical Bayesian method is employed during the calibration and operation steps of ultrasonic fatigue testing for the first time in this paper. This is particularly important due to the significant dispersion

The fatigue life of components under cyclic loading is highly sensitive to surface conditions, as imperfections lead to stress concentrations and early fatigue crack initiation. This study investigates the fatigue performance of both rough and smooth specimens made from S355 low-alloy carbon steel using a cold metal transfer (CMT)-based wire arc additive manufacturing (WAAM) process. Three types of

The influence of a hybrid surface modification combining fine particle peening (FPP), which is defined as peening using particles less than 200 μm in diameter, and sulfurizing on the fatigue properties of low-alloy steels (AISI4120) were investigated. Three types of sulfurized samples were prepared by electrochemical polishing and FPP with iron(II) sulfide (FeS) particles or steel particles as a pre-treatment

Fatigue crack closure (FCC) and growth (FCG) behavior under variable amplitude loading (VAL) are ubiquitous in engineering structures. With the plasticity-induced cack closure concept, Budiansky and Hutchinson (1978) pioneered the analytical FCC model under plane stress state and constant amplitude loading (CAL) conditions with stress ratio R ≥ 0. Here, we developed the analytical model into three-dimensional

As an advanced construction material, ultra-high-performance concrete (UHPC) has gained prominence in rehabilitating aging concrete infrastructure. When UHPC is bonded to normal strength concrete (NC), the interface between two types of concrete becomes a potential weak link, especially under fatigue loading. This vulnerability is further compounded by restrained shrinkage, which arises from the significant

This paper addresses the issue of the influence of geometry and size on the fatigue strength of steel butt weld joints. It aims to develop a series of continuously defined influencing factors, similar to the stress concentration factors in conventional un-welded notches. Such coefficients are mainly based on theoretical outcomes from Fracture Mechanics and Notch Mechanics and, where necessary, they

Blisks (bladed disks) are critical components in modern aero-engines that offer significant weight savings compared to conventional blade and disk rotor designs, resulting in improved fuel efficiency. However, due to their integrated design, blisks are susceptible to unique failure modes following foreign object damage (FOD) and crack initiation. Of particular interest is the trajectory of crack propagation

Effect of multilevel lamellar microstructures (MLMs) on notch high cycle fatigue (NHCF) property and microcrack initiation behavior of TC21 alloy were systematically investigated. The MLMs was created via a triple heat treatment, including parallel-aligned α laths (αlath) within the α colony (αc) and aged α fine lamellae (αfine) in the β transformation matrix (βtrans). Results indicate that microstructural

A fine-grained UHPC, both undamaged and damaged by fatigue loading, was comparatively examined by various microstructural analytical methods, to evaluate the different techniques with respect to their applicability and relevance for the investigation of fatigue damage processes. The fatigue tests were stopped at the transition from phase II to phase III of the s-shaped strain development. The cyclic

The study of the fatigue stiffness degradation behavior of carbon fiber composites under combined high and low cycle fatigue (CCF) loading is essential for the design of aviation structures subjected to cyclic loads. In this paper, an experimental study of plain weave composites (PWCs) is performed under designed CCF loading spectra, indicating that the superimposed high-cycle fatigue load significantly

Cold Spray is a solid-state deposition technique where metal powder particles are accelerated to supersonic velocities by a pressurised gas jet, forming a solid-state bond with the substrate through rapid, localised plastic deformation. Recent advancements in cold spray have enabled its application as an additive manufacturing and repair technology. This study investigates the structural integrity

Large data source for rotating bending fatigue tests of carburized steels obtained from a common research project were analyzed, and the factors influencing their fatigue properties were investigated from the viewpoint of microstructural characteristics and reliability engineering. The fatigue test results indicated that carburizing increased the fatigue strength of AISI 4120 steel, although the residual

The effect of multifunction cavitation (MFC) processing on the fatigue properties of carburized low-alloy steel rods was examined under rotating bending. MFC was conducted for electrochemically polished steel rods pre-treated with gas carburizing and tempering. In contrast to conventional surface modification techniques that use a cavitation jet, MFC can generate compressive residual stress and suppress

Unlike conventional wrought or cast martensitic steels, which are prone to embrittlement and hydrogen cracking, 3D-printed martensitic steels exhibit exceptional weldability due to their tailored microstructural homogeneity and reduced precipitate segregation. This study investigated resistance spot welds (RSWs) in additively manufactured martensitic steel under complex loading conditions, specifically

This research paper investigates the lifetime span and the crack propagation mechanism for a steel cylinder/plane contact under severe variable plastic fretting fatigue conditions that are representative of high pressure dynamic flexible pipe risers. An FEA model was used to predict the total life of the contact by separating the crack nucleation and the crack propagation mechanisms. Good correlation

This study presents a novel approach for reconstructing localized heat sources associated with fatigue degradation in metallic materials using 1D and 2D Inverse Heat Conduction Problem (IHCP) techniques, integrated with a Finite Element Method (FEM) framework. Traditional fatigue analysis methods are often constrained in their ability to analyze complex geometries. To address these limitations, an

Laser powder bed fusion (LPBF) provides advanced manufacturing capabilities for nickel-based superalloy, and solution aging treatment enhances its mechanical properties. However, the fatigue properties of solution-aged LPBF nickel-based superalloy at elevated temperature are not fully well understood. Here, high-cycle and very-high-cycle fatigue tests are conducted at 650 °C with stress ratios of R = −1

This study investigates the fatigue crack growth (FCG) behavior of laser powder bed fused (L-PBF) Ti-6Al-4V parts with an emphasis on the effects of notch orientation, stress ratio, R, and process-induced volumetric defects. Process parameters were altered during fabrication to induce different defect types and populations. FCG tests were conducted using compact tension specimens at stress ratios of

Fibre-reinforced polymer composites are generally seen as more fatigue resistant than metals. However, layup features such as discontinuous plies and/or manufacturing-induced defects such as wrinkles, can initiate fatigue damage and reduce the overall performance of composites. Through an extensive experimental programme and an advanced progressive damage model, this paper investigates the influence

In this article, strain-controlled Low-Cycle Fatigue (LCF) tests were performed on Inconel 718 nickel-based superalloy at temperatures of 300 °C, 650 °C, and 730 °C. The LCF tests were conducted at various mechanical strain amplitudes between 3.5×10−3 and 1×10−2, and three different mechanical strain rates: 1×10−4/s, 1×10−3/s, and 1×10−2/s. Cyclic straining resulted in cyclic softening under all investigated

A comprehensive investigation was conducted to elucidate the correlation between nitrogen-atmosphere heat treatment parameters and hydrogen embrittlement (HE) resistance in 304 austenitic stainless steel weldments. The HE susceptibility was quantitatively evaluated through in-situ slow strain rate tensile (SSRT) and fatigue crack growth rate (FCGR) tests under hydrogen exposure. Heat treatment temperature

The fatigue life of magnetic pulse crimping (MPC) joints is crucial for the safe fatigue design of connection structures. Traditional fatigue life prediction methods primarily rely on loading condition analysis and fail to fully account for the impact of manufacturing variations (such as raw material dimensions, process parameters, and joint deformations), which presents challenges for accurate fatigue

A theoretical analysis of random vibration fatigue is possible in time- or frequency-domain. In time-domain, sampled signal realizations are used, whereas the power spectral density (PSD) method is based on second-order statistics in frequency-domain. PSDs have important advantages over the sampled time-domain signals: (i) PSDs use a statistical model, enabling sound modeling of extreme value statistics

Accurate prediction of fatigue life under variable amplitude (VA) loading remains fundamentally challenged by load-sequence-dependent damage accumulation in metallic structures. This study establishes a nonlinear cumulative damage model integrating toughness exhaustion and strength degradation mechanisms through damage equivalence principles. Multi-level VA experiments on carbon steel, alloy steel

This study investigates the effects of mean axial and mean shear stresses on the fatigue life of Laser Powder Bed Fusion (LPBF) 18Ni300 maraging steel under uniaxial, torsional, in-phase, and out-of-phase axial–torsional loading conditions. A Gaussian Process (GP) model is employed to analyze fatigue life data, enabling (i) the estimation of the impact of specific mean stress components and (ii) the

A modified kinetic model for the status of stress-induced martensitic phase transformation is developed, and the reliability of the resultant constitutive governing equations is verified by the experimental data of stainless steel AISI 348. Then, a numerical simulation, based on the established constitutive governing equations with martensitic phase transformation, is performed to address the process

Accurately predicting MSD crack growth behavior in hybrid metal–composite structures is challenging due to the complex interactions of fiber bridging and delamination failure in fiber–metal laminates (FMLs). These mechanisms enhance damage tolerance but complicate crack analysis. This paper proposes two analytical models to address crack growth in FMLs with multiple collinear cracks. The first model

Gradient structures fabricated using plastic deformation methods have been demonstrated to exhibit excellent fatigue performances. However, achieving an optimal gradient structure remains challenging because of methodological limitations. In this study, nickel plates with varying grain-size gradient structures (GSs) were synthesized in a controllable manner via direct-current electrodeposition. Fatigue

Bolt preload plays a crucial part in ensuring the security of composite bolted joints. The actual bolt preload level displays noticeable fluctuation during aircraft assembly, impacting the fatigue reliability of joints. Assembly gaps commonly arise at the mating surface of composite airframes, and forced assembly is a prevalent method for closing the gaps before applying bolt preload, which leads to

Austenitic stainless steels, commonly used in light water reactor coolant environments, can be susceptible to environmentally assisted fatigue due to non-monotonic loading conditions, primarily associated with load-follow operations, thermal transients, or intermittent plant shutdowns and start-ups. The effects of a pressurized water reactor (PWR) environment containing hydrogen and cyclic loading