For structural applications subjected to rapid and cyclic loading, impact toughness and fatigue strength are critical properties that determine material suitability. CrCoNi medium entropy alloys (MEAs) have garnered attention due to their exceptional mechanical properties. Therefore, it is essential to assess the structural integrity of this alloy under harsh environments. This study investigates the

In-situ SEM fatigue testing is performed to investigate crack propagation through the heat affected zone as well as in the base material and deposited material in a wire and arc additive manufacturing (WAAM) low-carbon steel part. The slip band formation and development prior to crack initiation and the crack growth rate are monitored in-situ and compared using fatigue testing specimens sampled from

This study aims to systematically investigate the effects of hole diameter and sheet thickness on the quasi-static and fatigue behaviors of PH-SPR joints of high-strength steel and aluminum alloy. Quasi-static shear and fatigue tests, full-field strain measurements, numerical simulations, and microscopic observations are conducted to analyze the mechanical properties, failure behavior, failure mechanism

Aluminum alloy and its welded joint are widely used in high-speed trains, which are subjected to complex fatigue loadings in service. The fatigue failure mechanisms and influential factors for Base Metals (BMs) and Welding Metals (WMs) subjected to low cycle (dwell) fatigue (R = 0) and (very) high cycle fatigue (R = −1) loads were investigated. The development of cumulative strain in tension–tension

This work investigates the fatigue performance of AlSi10Mg-based architected materials fabricated using hybrid manufacturing and powder bed fusion (PBF) methods. For the analysis, cellular materials with triply periodic minimal surface (TPMS) topologies, including Gyroid and IWP architectures are manufactured and subject to load-controlled, compression-compression, cyclic loading. Quantitative fatigue

To investigate the temperature effect on the fatigue performance of plain-woven composites, a multi-information fusion method for damage identification under high-temperature conditions was established by integrating acoustic emission (AE), digital image correlation (DIC), infrared thermography (IRT) and scanning electron microscopy (SEM). Equipment for high-temperature AE and DIC acquisition was developed

This study presents a novel approach to predict the fatigue life of plain and notched polylactide (PLA) components 3D-printed with different in-fill levels. The proposed method models 3D-printed PLA with manufacturing voids as a continuous, homogeneous, linear-elastic, isotropic material weakened by equivalent cracks that scale with the size of the voids. This allows for accurate estimation of both

This paper investigates the high cycle tensile fatigue behavior of steel rebar reinforced − UHPFRC elements, at a fatigue load ratio, i.e., R-ratio of 0.3, representative for structural applications. Prior to testing, magnetoscopy is conducted on each specimen to determine the local fiber orientation and volume inside UHPFRC. During testing, global specimen deformation is recorded by displacement transducers;

Ultrasonic fully reversed tension fatigue tests have been performed in the Very High Cycle Fatigue (VHCF) regime (NR>107−108cycles) on Ti-6Al4V specimens containing a controlled internal notch. Two sets of samples have been used. The first one contains a central chimney along the specimen longitudinal axis which brings air to the internal notch; in the second series the notches are not connected to

Pressure tubes of Zr-2.5Nb alloy in Pressurized Heavy Water Reactors experience low cycle fatigue (LCF) due to cooling water flow and power fluctuations, which could be a factor destroying their structural integrity. Therefore, it is essential to systematically investigate their LCF properties and develop accurate life prediction models. Existing research primarily focuses on single-phase Zr alloys

Uniaxial and biaxial multi-path cyclic loading experiments were carried out using the plate dumbbell-shaped specimens and the cruciform-shaped specimens prepared by silane-modified polyurethane adhesive, respectively. The uniaxial testing results showed that the stress–strain curve of the material was nonlinear, and its mechanical properties were viscoelastic. The adhesive exhibited cyclic softening

Single-layer and double-layer Inconel 625 coatings were deposited on the Q235 steel using high-speed laser direct energy deposition (HL-DED). Steel grains in heat-affected zone (HAZ) coarsened due to the heat generated during the single-layer coating deposition. In contrast, double-layer coating specimens exhibited fine-grain regions in the HAZ due to repeated laser treatment reaching the solid-state

The current study aims to assess the high cycle fatigue strength of sharply V-notched bars under mixed mode I/III loading by applying the coupled Finite Fracture Mechanics (FFM) approach. FFM provides strength predictions by simultaneously satisfying a stress condition and an energy balance. A novel semi-analytical implementation of the FFM criterion is presented for the first time to account for a

This study investigates the fully reversed force-controlled fatigue response of a newly developed laser powder bed fused (LPBF) Al-Mg-Zr-Mn alloy (EOS Al5X1) in the post-aged condition. The fatigue behavior revealed a defect-driven response with a fatigue strength of approximately 140 MPa at 5 million cycles. Comprehensive microstructural analyses, including grain size, texture, and precipitate characterization

In this paper, the inclined cold expansion (ICE) method of superalloy open hole structures was proposed, which provided valuable insights for the life improvement of aero-engine inclined hole structures. The improvements in the static and fatigue properties of GH4169 specimens with inclined holes were characterized. In addition, tensile and fatigue tests were carried out, and the surface strains were

This study presents an experimental investigation of the fatigue performance and damage distribution mechanism of bi-directional GFRP composites. Uniaxial fatigue tests have been conducted under load-control, at stress ratios, R = 0.1, 0.5 and critical stress ratio (χ=-0.9). The influence of gauge length and surface roughness on fatigue life has been examined for R = 0.1. An infrared (IR) camera is

In order to expand the application scope of the quenching-partitioning-tempering (Q-P-T) steel in the industrial field, ultrasonic rolling treatment (USRP) is carried out, and the influence of USRP on the fatigue properties of the Q-P-T steel is elucidated. Compared with the Q-P-T specimen (580 MPa), the fatigue limit of the USRP3 specimen increases to 620 MPa, and the crack initiation location is

Casting aluminum alloy faces challenges during service, such as micro defects, low surface hardness, and inadequate fretting fatigue performance. This study employs acousto-electropulsing-stress synergistic strengthening to construct a strengthened layer structure on the surface of casting aluminum alloy, characterized by “micro-defect healing + surface gradient nanostructure.” The results demonstrate

This paper aims to study the effects of surface topography on the fatigue strength of wire-arc additive manufacturing (WAAM) components, paying particular attention to the interaction of roughness, waviness, and microstructure. For this purpose, first, a novel surface topography characterization approach is proposed to separate waviness and roughness without distorting the surface features, as smaller-scale

This paper presents a hybrid-driven probabilistic damage assessment approach by considering creep-fatigue-oxidation damage interaction (CFO-DI). Based on generalized strain energy density exhaustion (GSEDE) framework, the hybrid-driven concept integrates the strengths of both physics-based models and machine learning, exploring the frontier from deterministic evaluation to probabilistic assessment

High-strength cast Cu alloys often contain substantial quantities of alloying elements that promote the nucleation of heterogeneous particles, particularly at grain boundaries (GBs). In the Cu-6Ni-1.3Si alloy, intermetallic compounds such as Ni2Si form within the matrix and along the GBs following homogenization. Ni2Si particles within the matrix are homogeneously nucleated with diameters of a few

Accurate fatigue life prediction of additive manufactured parts is critical for the reliability and safety assessment of the designs made for aerospace applications. The fatigue life depends on the cyclic stress experienced due to loads in operation, surface roughness, internal microstructure, and defects in the parts. The microstructure of a material contains signatures of the manufacturing process

Fatigue crack growth (FCG) tests were conducted on superelastic NiTi alloys, demonstrating that the da/dN-ΔK curve in the stable crack growth stage exhibits two transition points in the double-logarithmic coordinate system, presenting a tri-linear form. Fracture surface SEM analysis indicated that the FCG mechanisms differ across the three stages on either side of the two transition points. This phenomenon

Creep-fatigue reliability assessment for high-temperature equipment is crucial but challenging due to the extensive data requirements and cumbersome methods. To enhance the implementation of creep-fatigue reliability assessment within engineering practice, this study employs multidimensional computational techniques grounded in the hybrid-driven paradigm. In detail, it presents a hybrid-driven creep-fatigue

A fatigue fracture mechanics methodology was developed and established, employing a slope-based J-integral approach combined with advanced image processing techniques. Adhesively bonded double cantilever beam (DCB) specimens were tested under constant displacement amplitude loading. The beam rotation was tracked by affixing a repetitive pattern on the DCB specimens and capturing images at the maximum

This study investigated the fatigue crack propagation behavior from small defect in the elastic–plastic region under block loading conditions and clarified the influence of cycle ratio on the crack growth rate. Fatigue tests were conducted under constant and repeated two-step strain amplitude loading conditions using various cycle ratios. The results of the constant amplitude loading test indicated

The fatigue assessment of structural components, especially made of ductile cast iron subjected to complex loading conditions, heavily relies on analyzing fatigue damage resulting from stress concentrations induced by geometric irregularities like notches and shrinkage pores. Standard methodologies, encompassing the Theory of Critical Distances (TCD), Strain Energy Density (SED), and Critical Plane

In this study, the relationship between fatigue life and the feature parameters of fatigue fracture surfaces was statistically analyzed to successfully develop a new fatigue life prediction approach. Results showed that the inclusion location was an important parameter affecting fatigue life besides stress amplitude, inclusion size and material hardness. A new stress concentration influence factor

Laser cladding holds the promise to repair damaged rails, including flange tip lift crossings (FTLC) in tram rails. In order to further understand the effectiveness of laser cladding against rail damage, this study investigated the ratcheting behaviour of the laser cladding alloy Stellite 21, used in FTLC repairs, in comparison to the currently used rail steel grade R260. Experimental studies were

The macroscopic morphology and microstructure evolution mechanism of the FGH95 alloy were investigated with regard to fracture under low-cycle fatigue at different temperatures. The fracture modes of the FGH95 alloy at 420 °C, 510 °C, and 600 °C were found to fall into two main categories: shear fracture at low temperatures (420 °C, 510 °C) and I type fracture at high temperatures (600 °C). The change

Based on strain-controlled thermomechanical fatigue (TMF) experiments, this study conducts a comprehensive analysis of the TMF behavior of AISI H13 hot work die steel. Moreover, a life prediction model for the TMF behavior of AISI H13 steel has been developed and validated. The experimental results reveal that, under the in-phase (IP) and out-of-phase (OP) TMF conditions, the stress–strain response

The effects of blast cleaning (BC) and stress relief annealing (SRA) on butt joints were investigated. BC leads to a significant increase in fatigue strength due to insertion of compressive residual stresses and cold work hardening at the surface. Additional SRA leads to a decrease of fatigue strength down to the as-welded state. It is shown that the SRA not only leads to a decrease of compressive

Within polycrystals, significant stress concentrations can arise due to their heterogeneous nature. These stress intensities strongly influence the onset of nonlinear behaviors, such as plasticity and fatigue damage. One often overlooked source of heterogeneity is the crystal anisotropy and its resulting neighborhood effect. Previous research introduced a data-driven analytical model based on a cellular

The LCF behavior of SU-263 was investigated at various temperatures (1073, 1123, and 1173 K) and strain amplitudes of ± 0.4 to 0.8% at a constant strain rate of 3 × 10-3 s−1. The alloy displayed initial hardening followed by extensive cyclic softening until failure. It is observed that the presence of dislocation networks absorbs mobile dislocation, and the shearing of γ′ precipitates were responsible

The aim of this study is the formation and numerical-experimental background of the approach to assessing of the structural integrity based on the principles of tolerance damage and simulation modeling. To this end, constitutive equations of the Lemaitre model and phase field fracture are employed, which include damage functions for the stages of defect appearance and crack growth. A general system

The fatigue test was carried out to investigate the fracture morphology and fatigue life of stress-corroded steel wires. The influence of stress corrosion degree on the initial value of crack propagation and fracture toughness of steel wires was explored. The theoretical method of crack initiation and propagation life of corroded steel wires based on CM-EIFS (Corrosion Modified Equivalent Initial Flaw

Under combined high and low cycle fatigue (CCF) loading, the multi-axial stress state induced by geometric discontinuities of different notch forms under the same stress amplitude can result in significant differences in fatigue performance of DD6 alloy. Therefore, it is of great importance to study the CCF behavior of Ni-base single-crystal alloy samples with differing notch geometries at the high

This study aimed to identify the microstructural factors governing the torsional fatigue strength of bainitic steels. Torsional fatigue tests were performed on two bainitic steels with banded microstructures comprised of soft and hard layers. The soft layers were coarse-grained with low Vickers hardness (HV), while the hard layers were fine-grained with high HV. Both materials possessed similar average

Fatigue crack growth in ductile materials is primarily driven by the interaction between damaging and shielding mechanisms. In the Paris regime, the predominant mechanism for retardation is plasticity-induced crack closure (PICC). However, some of the mechanisms behind this phenomenon are still unclear. Identifying and separating the three-dimensional aspect from other shielding aspects during experiments

In recent years, Polymer-Matrix Composites (PMCs) have gained increasing attention across various sectors. With this growing interest and usage, accurately determining their mechanical properties, including the fatigue properties, has become crucial. Traditional methods for these evaluations are both time-consuming and costly, prompting the development of easier and more cost-effective methods for

The clean fuels of ammonia and methanol are used to replace diesel in shipbuilding industry, but there exists corrosion risk for the engine parts in combustion products. The corrosion fatigue behavior of cylinder liners cast iron in simulated combustion product solutions of ammonia, methanol and diesel fuels were investigated. The corrosion rate and corrosion fatigue sensitivity in the three simulated

Composite materials are particularly exposed to delamination under fatigue loading conditions, which can significantly compromise their structural integrity. The ability to accurately and efficiently estimate the progression of delamination under fatigue is crucial for enhancing the safety and reliability of lightweight composite structures. The aim of this paper is to implement the cohesive elements

In the industrial sector, laboratory tests are frequently performed to evaluate the durability of structures under mechanical loads. These tests typically involve sequentially applied uniaxial loads, even though operational conditions are often multiaxial. To address this inconsistency, a new frequency-domain approach has been developed to generate test-tailored specifications for multiaxial vibration

A new nonlinear fatigue cumulative damage model is proposed to address the challenge of insufficient accuracy in calculations stemming from nonlinear cumulative damage models that fail to account for strength degradation effects and interactions among multi-level loads. This model, an enhancement of the Aeran fatigue damage model, incorporates stress ratios to capture load interactions and includes

This study investigates two key aspects of the low cycle fatigue (LCF) behavior of alloys from the Cr-Mn-Fe-Co-Ni system at room temperature: (1) the influence of stacking fault energy (SFE) in single-phase face-centered cubic (FCC) alloys and (2) a grain size reduction triggered by the precipitation of a small amount of σ-phase. The first effect is investigated using model alloys (Cr26Mn20Fe20Co20Ni14

The fatigue experiments for titanium alloy Ti60 under different uniaxial/multiaxial thermo-mechanical loading modes found that the combined action of high temperature and tensile stress can cause the debonding of the second phase strengthening particles between grain boundary, reducing the ability to resist deformation of Ti60, which leads to a decrease in the fatigue life of the material. In addition

Titanium alloy welded structures are often subjected to cyclic loading with composite waveform and variable amplitude during actual service, exacerbating the damage to the joints and leading to low fatigue life. Therefore, a three-stage heat treatment was adopted in this work to enhance the fatigue life of TC4 titanium alloy pulsed laser-arc hybrid welded joints, and its microstructure evolution and

This paper introduces a digital twin solution for corner fatigue crack growth assessment. The digital twin comprises three core features: (1) diagnosis, (2) prognosis and (3) updating. The diagnosis arm performs remote crack size measurement via strain data collected from strategically identified locations. The prognosis component postulates the fatigue life across both linear-elastic and elasto-plastic

The work is devoted into investigating the multiaxial low cycle fatigue behavior and constitutive model of 316L under various strain amplitudes, strain ratios, and phase angles at 550 °C. Experimental results show that both axial and shear stress amplitudes present three stages of cyclic hardening, softening and fracture. Internal stress analysis reveals that initial cyclic hardening is influenced

The present paper studies fatigue crack growth (FCG) produced by a load pattern obtained numerically in a simulation of trains crossing a real bridge. It uses a model where the cyclic plastic deformation is assumed to be the main damage mechanism and that cumulative plastic strain at the crack tip is the driving parameter for FCG. The accumulation of damage was found to be very irregular along each

The ultra-high-strength engineering cementitious composites demonstrates pseudo strain hardening behavior when subjected to uniaxial tension, making it a promising material for enduring repeated or fatigue loads. Extensive research has been conducted on the quasi-static, dynamic, and fatigue behavior of this composites. However, due to the challenges of conducting direct tensile testing on concrete

Multiaxial fatigue life prediction models rely on intrinsic parameters that provide the balance between arbitrary and reference stress/strain conditions. However, this balance may be compromised due to evolving damage mechanisms, causing initially determined model parameters to deviate from actual values, resulting in life prediction errors. Despite the significant impact of fatigue model parameters

Currently, there is a lack of reliable approaches for the fatigue assessment of adhesively bonded joints that are subject to multiaxial stresses with variable amplitudes. To improve the current situation, investigations are made on the capability of three multiaxial evaluation approaches based on fatigue tests of adhesively butt-bonded hollow cylinders under multiaxial loading with constant phase shift

An experiment was conducted to evaluate the creep-thermal fatigue (CTF) behavior of thin-walled structures with holes. To achieve this, a high-temperature hold phase was added in the testing. The crack propagation of CTF is driven by the combined effects of creep, thermal fatigue, and oxidation. Therefore, a creep-thermal fatigue-oxidation phase field model was developed to simulate CTF behavior. The

The fatigue-induced fracture failure of the aircraft canopy occurred in the poly(methyl methacrylate) (PMMA) layer laminated on polycarbonate (PC) during flight. For more than 24 years, the aircraft had been operated at high altitudes and supersonic flight. To identify the root cause and the mechanism for the formation of the fracture, the fracture surfaces were investigated. The fracture morphologies

Fatigue crack growth (FCG) tests were conducted on compact tension specimens made of a Ni-based superalloy to investigate the near-threshold FCG behaviors using both the stepped load reduction method (LRM) and the constant-amplitude loading method (CALM) at three stress ratios (R = 0.05, 0.5 and 0.7) under ambient condition. It is found that after the FCG threshold being approached by the LRM, a remarkable

In order to isolate the influence of ply orientation on the mode I fatigue delamination propagation behavior of carbon fiber reinforced composite laminates, multidirectional laminates with the same overall stiffness are designed while three different interfaces (0//0, 45//45, and 90//90), which can avoid the coupling effect of remote plies. Test results show that the fatigue delamination behavior is

A three-layered experimental thermal and environmental barrier coating (TEBC) was deposited using air plasma spraying technology on cylindrical specimens of nickel-based superalloy MAR-M247. TEBC consists of mullite (Al6Si2O13) and hexacelsian (BaAl2Si2O8) upper layer, Y2O3 stabilised ZrO2 interlayer and CoNiCrAlY bond coat deposited on the grit-blasted surface of MAR-M247. The cyclic plastic response

Exploring the long-term performance of welded details in composite trapezoidal corrugated web (TCW) girders is a significant focus for the service life of these structures exposed to atmospheric environment and traffic flow. The majority of the present studies have been conducted without accounting for thermal stresses induced by temperature differences and accurately reflecting internal force transfers