We demonstrated here the effect of welding heat input on the microstructure characteristics and fatigue behavior of the multi-pass welded joint of a FH690 grade ultra-heavy steel plate. The welded joint with a heat input of ∼15 kJ/cm exhibited higher ultimate fatigue stress (407 MPa at endurance limit of 107 cycles) than that of ∼50 kJ/cm. Moreover, the welded joint with a heat input of ∼15 kJ/cm fractured

Despite the critical importance of mechanical reliability in our modern economy, the prediction of fatigue failures remains a challenging endeavor. Traditional fatigue testing methods are not only slow and costly but also plagued by high variability, making it difficult to calibrate predictive models for real-world utilization. Towards addressing this challenge, we present a uniaxial mechanical fatigue

Understanding the fatigue behaviour of natural rubber is crucial for designing rubber components such as chassis and motor mounts. These components experience multiaxial loading during operation, which affects both mechanical behaviour and lifetime, for instance, due to self-heating or strain-induced crystallisation. In this study, a new methodology is introduced to analyse the fatigue behaviour of

Great attention has been attached to Al-Li alloys due to their excellent performance for aerospace structural components, which endure low-temperature environments and cyclic loads, posing intense demands on the fatigue resistance of materials. In this work, the fatigue crack propagation (FCP) behaviors at low temperatures (−80 °C) of as-rolled 2195 Al-Li alloy have been investigated and compared with

This article proposes a novel phase-field length scale insensitive model for fatigue failure in brittle materials. In the proposed model, we incorporate a necessary fatigue-related parameter to define the fatigue threshold energy as a function of the fracture strength and make the mechanical response of a material insensitive to the phase-field length scale. In the proposed model, we derive the governing

Thermo-mechanical fatigue (TMF) is a complex damage mechanism considered to be one of the key issues limiting the service lives of hot section components in a gas turbine engine. Turbine blades and nozzle guide vanes are particularly susceptible to this form of material degradation, which results from the simultaneous cycling of mechanical and thermal loads. In this research, a series of TMF tests

Multiaxial fatigue under complex asymmetric loading paths has gained significant attention because it better represents the actual loading conditions of engineering components. However, research on this topic remains limited. In this study, a definition of the multiaxial fatigue stress ratio is proposed by identifying the peak and valley points of complex loading paths. Subsequently, the Walker mean

This study presents the effect of immersion in Simulated Body Fluid (SBF) on the fatigue behavior of Polylactic Acid (PLA) and PLA-wood composites. For the degraded fatigue tests, the testing specimens were 28 days submersed in 10X SBF, weighed, and then fatigue experiments were done. The immersed samples gained weight due to water absorption. Additionally, mineral deposits grew on their external shells

This study investigated the fracture mechanisms of dovetail joints under very high cycle fretting fatigue (VHCFF) loading and predicted the short crack propagation behavior through experiment and simulation. Dovetail specimens designed and manufactured using Inconel 718 superalloy are tested at room temperature (RT) and high temperature (650 °C). The scanning electron microscopy (SEM), electron backscatter

Nanoprecipitates typically strengthen alloys by blocking dislocation movement, but herein, they can be sheared off continually during fatigue. Cyclic slip irreversibility accumulates continually, with the local shear strain reaching ετ = 57.6 %. We reveal that dislocations slipping on the basal plane experience different critical resolved shear stress (CRSS) as they pass through the β′-nanoprecipitates

Creep-fatigue experiments were conducted on IN740H, a γʹ-lean Ni-based superalloy, at 750 °C with a strain ratio of −1, a strain amplitude of either 0.3 or 0.5 %, and a dwell period at the maximum strain of 0, 120 and 600s. Results indicate that the number of cycles to failure decreased with the dwell period, although overall rupture time increased. Grain boundary fracture was more prevalent at higher

Accurately predicting the fatigue life of welded components remains a challenging task. This work compares different geometric approaches, such as scanned or idealised weld geometries, using energy-based and strain-based fatigue damage parameters. Gradient effects have also been successfully considered and investigated. In addition to the analytical calculation using the damage parameters, the fatigue

Fatigue of metallic materials produced by Laser Powder Bed Fusion has been extensively studied for both standard testing specimens and application relevant components. However, fatigue properties of specimens and components suffer from large scatter, mainly due to the presence of volumetric anomalies, residual stresses and surface roughness. Therefore, the transferability from specimens to components

The notch, such as hole and chamfer, is unavoidable for aircraft structural components. Stress concentration induced by notch is the leading cause of fatigue failure. It is significant for structural integrity and safety assessment to clarify the intrinsic mechanism causing the difference in fatigue notch sensitivity. The notch fatigue fracture behavior of TC11 samples, fabricated by laser direct energy

Three-phase composites, especially those composed of high performance thermoplastics, have not been properly investigated with respect to their interlaminar fracture toughness. Therefore, this study investigates effect on the interlaminar fracture toughness by adding carbon nanotube buckypaper (BP), tested under cyclic loading in mode I and II. BP weakened the interlaminar fracture toughness in mode

Wearable flexible thermoelectric generators (WFTEGs) offer a promising solution for integrating power sources with electronics in wearable technologies. However, the longevity of these devices is compromised by fatigue propagation in brittle thermoelectric materials due to internal cracks. This study presents a three-dimensional (3D) numerical model of WFTEGs with through-thickness cracks, accounting

Medium-manganese transformation-induced plasticity (TRIP) steel, a new generation advanced high-strength steel, exhibits a combination of excellent strength and plasticity. Due to the TRIP effect, the cyclic deformation behavior and mechanisms of the steel are more complicated, especially at elevated temperatures. In this work, the monotonic and cyclic deformation of Fe-0.4C-7Mn-3.2Al steel were investigated

The corrosive marine environment brings significant challenges to traditional steel materials, prompting the exploration of alternative solutions in terms of advanced structural materials, such as titanium-clad (TC) bimetallic steel. This paper presents an experimental investigation into the basic mechanical properties and high-cycle fatigue behaviour of hot-rolled bonding TC bimetallic steels with

Ambient-temperature, low-cycle dwellfatigue, conventional low-cycle fatigueand creeptests have beenperformed on additively manufactured and Hot Isostatic Pressed (HIPPED) Ti-6Al-2Sn-4Zr-2Moalloy.The low-cycle dwellfatigue life comparedwith the low-cycle fatiguelife showed a dwell debit of 5. The factor decrease in thelow-cycle dwellfatiguelifefrom the low-cycle fatiguelife remain almost same withdecreasing

In this paper, a fatigue life prediction model of surface strengthening materials is proposed by considering dominant surface integrity parameters. The maximum residual stress and maximum microhardness of the surface strengthening materials are determined as the dominant parameters for the development of fatigue life prediction model according to the correlation analysis between surface integrity parameters

The incorporation of a toughening agent in the production of Carbon Fiber Reinforced Polymer (CFRP) can mitigate crack propagation inside the matrix, which is significant for enhancing the product’s fatigue life. This study presents the preparation of T300 carbon fiber reinforced epoxy resin composite utilizing a wet toughening process, incorporating the thermoplastic monomer Polyamide 6 (PA6) into

For the first time, 45 steel and Pb were welded to form Fe-Pb thin-walled heterogeneous welding material components, which can be used in heavy-duty and radiation resistant environments. This study conducted comparative shear fatigue tests under different alternating loads under the conditions of hot isostatic pressing (HIP) control technology. The experimental results are as follows: after HIP treatment

In-phase and out-of-phase thermomechanical fatigue (TMF) tests with the temperature cycling from 300 °C to 650 °C were carried out on 316H stainless steel. The isothermal fatigue (IF) tests at 650 °C were performed for comparison. A wide range of strain amplitudes from 0.185 % to 1.0 % were used. Results showed that TMF loading resulted in the more pronounced cyclic hardening than IF loading, and the

Low-cycle fatigue behaviors of 304L stainless steel were investigated under different strain amplitudes (0.25 %, 0.3 %, 0.4 %, 0.5 %) and number of cycles to establish the relationship between macro-properties and micro-mechanisms. In all cases of strain amplitude, the 304L stainless steel displays a slight degree of cycle softening subsequent to the initial hardening in the cyclic stress–strain response

The role of environmental degradation, particularly oxidation, on the low cycle fatigue response of rotating blades of aero-engine operating at significantly high temperatures is extremely important as it adversely affects its performance. The present work investigates the coupling effect of prior cyclic oxidation and temperature on the low cycle fatigue (LCF) fatigue behaviour of CM 247 DS LC Ni-based

A cyclic elasto-plastic constitutive model based on physics informed neural network is constructed to describe the cyclic hardening as well as non-Massing behaviors of oxygen free highly conductive copper under fully reversed strain-controlled loading. By translating and rotating the data points, the tension branch and compression branch in stress–strain hysteresis loop are unified. Internal variables

This study investigates the influence of microstructural size and stress gradients on crack nucleation in ferrite-pearlite steel under cylinder/plane fretting conditions. An experimental and numerical approach establishes a critical distance that correlates with grain size, revealing a significant distinction between elastic and elastoplastic behaviour. The results indicate that the optimal critical

We propose a fracture mechanics based method for determination of equivalent initial damage size (EIDS) distribution in as-built additively manufactured (AM) Ti-6Al-4V notched geometries. The crack growth model is shown to correctly capture the effect of the stress raisers and load ratio on the fatigue life of notched specimens. Results of constant amplitude fatigue tests on notched round bar specimens

Ti-6Al-4V alloy is subjected to complex environmental conditions, often requiring enhanced fatigue performance in engineering applications. This study provides a comparative analysis of the effects of micro-shot peening (MSP) and traditional shot peening (TSP) on the fatigue performance of Ti-6Al-4V alloy. The results indicate that TSP specimens develop a work-hardened layer with high hardness and

The fatigue crack propagation (FCP) property and strength in T8-aged Al-Li alloy sheets with varying solid-solution time were investigated and the influence mechanism of the secondary phase on fatigue crack initiation was revealed. The results demonstrate that both grain dimension and recrystallization texture of the alloys with different solid-solution time are similar, but the average diameter of

The large-scale wind power spindles are prone to fatigue failure under cyclic loading, particularly, due to microstructure inhomogeneity of tempered large-scale forgings, it is of great significance to explore the influence of non-uniform tempered sorbite/bainite (TS/B) on fatigue crack propagation and closure effects. In this paper, the fatigue crack propagation behavior of coarse TS/B and fine TS/B

Creep-fatigue behavior of a friction stir welding (FSW) Al-Zn-Mg-Cu alloy at different temperatures was investigated. The results show that creep damage is much higher than fatigue damage when a holding time is introduced at the peak load. After creep-fatigue, η’ and η phases are reprecipitated in the weld nugget zone (WNZ) and coarsen with increasing temperature. When the creep-fatigue temperature

The interesting phenomenon of facet cracking of Ti-2Al-2.5Zr alloy exposed to high-cycle fatigue (HCF) loading at the high temperature of 350 °C was reported for the first time. Moreover, the HCF tests at room temperature were also conducted for comparison. The crack nucleation mechanisms with essential differences at both room and elevated temperatures were comparatively studied based on the elaborate

Two polymer foams with density of 0.10 and 0.13 g/cm3 (F10 and F13) respectively were fabricated by steam-welding of expanded beads, obtained from super-critical foaming of poly(ether-b-amide). The compression fatigue behaviors were first characterized by step-increase strain tests up to −60 %, with an increment of 10 %. The stress relaxation rates during every one thousand cycles of compression was

The low density, high strength, and excellent high-temperature resistance of ceramic matrix composites (CMCs) determine their significant application value in the extreme environments of advanced aero-engines. In this paper, the thermal shock performance and internal damage evolution of CMCs materials are investigated by X-ray computed tomography (XCT), infrared thermal imaging and acoustic emission

The development of hybrid bonds between copper and aluminum is being pursued for reasons of cost, functionality, and weight, particularly in the field of electromobility, to achieve near net-zero emissions. Joining aluminum to copper is a challenge, as interfacial intermetallic compounds have a negative impact on the strength, ductility, and electrical properties of the joint. The development of brittle

In this paper, the influence of sintering process on the high temperature cyclic deformation behavior and fatigue creep damage mechanism of sintered silver is revealed. Under cyclic shear loading at high temperatures, quasi cleavage fracture that symbolizes creep damage is induced in sintered silver, leading to a decrease in its fatigue life. With the increase of sintering temperature/time, the material

Due to the complexity of loads and structures, as well as the uncertainty of transverse crystal orientation, accurately predicting thermomechanical fatigue (TMF) damage in nickel-based single crystal turbine blades remains a challenge. In this paper, a slip-based damage model reflecting the coupling of creep damage and low-cycle fatigue damage was employed to describe the in-phase thermomechanical

Fretting fatigue cracks can occur in the wheel seat of railway axles, posing a risk to safe operation. This study investigates the critical crack depth that ensures the fatigue strength of railway axles remains within acceptable limits. Fretting fatigue tests were performed on scaled press-fitted axles with circumferential groove defects of varying depths. Results showed that as the defect depth increased

The low-cycle fatigue (LCF) and creep-fatigue interaction (CFI) characteristics of 630R ferritic/martensitic heat-resistant steel at 630 °C have been examined. The LCF tests were conducted within a strain range of 0.3 % to 1.0 %. CFI assessments were conducted using trapezoidal waveforms with varying strain amplitudes and load holding durations. The progression of cyclic stress, hysteresis curves,

Fretting fatigue is a common phenomenon between contacting components that significantly reduces the life of the specimen due to stress concentration and surface wear. Shot peening is a widely used surface strengthening technique that improves fatigue life by introducing surface hardening and residual stress fields. This study employed a bridge-type pad and flat specimen test setup to investigate the

Ni-base superalloys used in gas turbine blades are often directionally-solidified (DS) or single-crystal (SX) to minimize grain boundaries and enhance creep resistance. However, their anisotropic elastic properties cause significant variability in mechanical response depending on the loading direction, particularly for components with complex geometries. Predicting thermomechanical fatigue (TMF) and

Fatigue failures pose significant challenges across various engineering disciplines. Wood, due to its low carbon emissions and high strength-to-weight ratio, has been gaining attention in engineering applications. The fatigue behavior of wood is complex due to its heterogeneous, anisotropic, and viscoelastic nature. This research explores essential insights into the fatigue behavior of wood, with a

Fatigue crack growth (FCG) is usually associated with cyclic plastic deformation at the crack tip. However, this damage mechanism loses dominance for relatively low stress intensity factor ranges (ΔK), and a lower boundary must be considered in numerical modelling. So far, the definition of this lower boundary and its variation with the stress ratio remain unclear This paper studies FCG in CT specimens

Welded joints are typically key regions for crack initiation and propagation, making it especially important to study their fatigue behavior under different loading conditions. This study extends the classic mode I Christopher-James-Patterson (CJP) model and proposes a multiaxial CJP model tailored for welded structures. The study incorporates parameters that drive and resist crack propagation, defining

Asphalt binders are crucial in roadway construction, significantly influencing the performance and durability of asphalt mixtures. Even with identical mix designs, the performance of these mixtures can vary depending on the Performance Grade (PG) of the binder used. This study aims to identify and evaluate test methods for assessing binder quality, specifically in terms of cracking resistance. Twenty

Engineering materials are occasionally subjected to high-frequency impact fatigue in service. However, there are still gaps in the loading techniques that hinder the acquisition of sufficient experimental data. In this work, we developed a novel loading methodology based on stress wave guidance to achieve controllable impact fatigue of ∼ 1 kHz frequency. Hopkinson tension bar was modified first by

This study quantified the relationship between the microstructural characteristics and the fatigue life of the IN713C alloy turbocharger turbines prepared using centrifugal investment casting. The samples were obtained directly from the components for fatigue testing experiments to reveal the fatigue fracture mechanisms of different microstructures. The results showed that fatigue cracks at the root

The aim of this study is to model the impact of surface roughness and pores on the fatigue strength of plain and V-notched specimens made of Inconel 718 under as-built and machined conditions and produced by laser powder bed fusion (LPBF). Combining fractographic analyses with the Gumbel and the exponential distribution functions, the statistical analyses of the diameters of the pores and of their

The hypothesis is examined that the macrozones that can occur in large Ti-6Al-4V forgings, in combination with the effects of stressed volume and sustained loads, can result in a debit in high cycle fatigue (HCF) performance, which would be of concern in jet engine applications. Here, the effect of placing a notch root in hard vs. soft oriented macrozones, i.e. {0002} parallel or perpendicular to the

Fatigue criteria for nonproportional loading often rely on the premise that damage initiates on the plane with the highest shear stress range. Due to the reciprocity of shear stress, at least two equivalent planes in 3D space can be found. Among these, the most critical plane is determined by its normal stress, as tensile stress on the crack surface facilitates damage formation. Many loading scenarios

Crack growth and closure behavior in Fe–15Mn–10Cr–8Ni–4Si steel were investigated. The steel showed slower crack growth compared with SUS316. This was mainly due to the pronounced effect of crack closure. The gradual cyclic hardening in the Fe–15Mn–10Cr–8Ni–4Si steel have enhanced the effect of plasticity-induced crack closure compared with that in SUS316. Additionally, the rough fracture surface consisting

The S38C steel axles show excellent fatigue resistance due to large-depth compressive residual stress (CRS) along the axial direction. However, residual stress (RS) relaxation may occur in case of a fatigue crack, which results in a reduced damage tolerance and a shortened service lifetime. Destructive methods cannot retain the residual stress and associated retardation effect of cracks. To tackle

This study concentrates on the fatigue crack propagation behaviour of a high-strength low-alloy (HSLA) steel and austenitic stainless (AS) steel bi-material part, as obtained by wire arc additive manufacturing (WAAM). Due to partial mixing in the weld pool, the first layer of AS steel laid onto the previously deposited HSLA steel results in a diluted interface layer of distinct chemical and microstructural

Complicated interaction of twin boundary with dislocation plays a pivotal role in mechanical properties. In this study, the effect of TB on the fatigue crack initiation of Inconel 718 superalloy was investigated in vacuum environment of 650 ℃. A three-point bending fatigue test with preprocessed plate specimen was applied to trigger multi-source crack initiation. Plenty of slip band patterns and crystallographic

Stacking fault energy (SFE) plays a key role in the deformation mechanisms and mechanical behavior of metallic materials. However, the low-cycle fatigue (LCF) behavior of low SFE materials remains unclear. This work presents the monotonic tensile and LCF behaviors of Co35Cr42Ni23 alloy with very low SFE. In contrast to the dislocation-dominated deformation mechanism in equiatomic CoCrNi alloy, planar

Aircraft tires are a critical component for the takeoff, landing, and taxiing of an aircraft. Under high-speed and heavy-load conditions, aircraft tires are subjected to huge stresses and remarkable heat build-up. Improving tire safety and service life is crucial. The deformation index can be used to judge the control modes of different components of the tire, such as strain control, stress control

The strain distribution along the cantilever piezoelectric energy harvester (PEH) beam is nonuniform, which would induce fatigue damage at the root of the cantilever in the long run, and cause failure in the piezoelectric material. In this study, fatigue vibration experiments are repeated to determine and analyse fatigue characteristics and output performance changes of the improved structures under