Article
Chemistry, Physical
Michael Fitzka, Bernd M. Schoenbauer, Robert K. Rhein, Niloofar Sanaei, Shahab Zekriardehani, Srinivasan Arjun Tekalur, Jason W. Carroll, Herwig Mayer
Summary: This study summarizes the comparability of fatigue properties measured with ultrasonic and conventional equipment, focusing on the performance of different materials at ultrasonic frequencies. Aluminium alloys and high-strength steels are insensitive to cycling frequency, while the strain rate sensitivity of ferrite may lead to prolonged lifetimes.
Article
Engineering, Mechanical
Hamed Ghadimi, Arash P. Jirandehi, Saber Nemati, Shengmin Guo
Summary: This paper presents a small-sized bending-fatigue test specimen design for an ultrasonic fatigue testing system, which is optimized based on finite element analysis and analytical-solution results to achieve proper vibration shape and stress distribution under high- and very-high-cycle fatigue regimes at 20 kHz frequency. Both simulation and testing results confirm the desirable vibration mode and specimen failure at the designated test section with maximum stress, leading to the stress-life (S-N) curve for Inconel alloy 718.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Mechanical
Pedro R. da Costa, Luis Reis, Manuel Freitas
Summary: Ultrasonic fatigue testing is a method that uses resonance to achieve very high cyclic load frequencies for studying high cycle fatigue. This study modified the geometry of the specimen and conducted numerical and experimental modal behavior analysis to achieve reliable multiaxial fatigue testing. The results prove a clear trend in crack propagation details with the increase of the induced stress ratio.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Engineering, Mechanical
Pedro R. da Costa, Masoud Rahaeifard, Diogo Montalva, Luis Reis, Manuel Freitas
Summary: Ultrasonic fatigue specimens require rigorous design to ensure resonance vibration at high frequencies and desired mode shapes. Existing analytical methods for uniaxial tension-compression or pure torsion specimens limit the range of experiments. This paper proposes a semi-analytical formulation for complex ultrasonic specimen geometries under multiaxial tension-torsion, showing good correlation with numerical simulations. This work can facilitate the design and conduct of more varied and efficient ultrasonic fatigue experiments.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Xavier Lesperance, Paul Ilie, Ayhan Ince
Summary: This study investigates the long fatigue life characteristics of AlSi10Mg and AlSi7Mg aluminium alloys produced using direct metal laser sintering. The results of fatigue tests suggest that the effects of heat treatment on high cycle fatigue and very high cycle fatigue performance of additive manufacturing alloys should be further explored in the context of microstructural changes.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Mechanical
Shawn L. Kiser, Marc Rebillat, Mikhail Guskov, Nicolas Ranc
Summary: Ultrasonic fatigue tests are used to study the fatigue life behavior of metallic components undergoing a high number of cycles under low mechanical loads. This paper introduces a spectral estimation method for extracting vibration signal parameters and recommends suitable algorithms for processing experimental data obtained from ultrasonic fatigue tests.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Acoustics
Michael Fitzka, Ulrike Karr, Maximilian Granzner, Tomas Melichar, Martin Rodhammer, Alfred Strauss, Herwig Mayer
Summary: In this study, the cyclic compression fatigue properties of concrete were investigated using the ultrasonic fatigue testing method, showing the applicability of ultrasonic testing for rapid generation of VHCF data. Methods such as observing resonance frequency, analyzing higher order harmonics of vibration, and computed tomography of specimens were successful for analyzing fatigue damage. Calorimetric evaluations were used to calculate cyclic irreversible strain in the ultrasonic VHCF test, being approximately 1% of the elastic strain.
Article
Engineering, Mechanical
G. Morettini, C. Braccesi, F. Cianetti, S. M. J. Razavi
Summary: Multiaxial random experimental fatigue tests were conducted with a new specimen geometry, using a circular specimen and a frequency resonance system. The proposed modal approach was validated both numerically and experimentally. The goal of the study was to define the Wodhler curve of the component using forecast data from the BVM method, with fractography analyses of the tested specimens to complete the investigation.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Review
Engineering, Mechanical
Jan Papuga, Adam Kal'avsky, Maxim Lutovinov, Ivona Vizkova, Slavomir Parma, Martin Nesladek
Summary: This paper establishes clear rules for evaluating experimental data for validating multiaxial fatigue strength criteria, aiming to identify and eliminate data that could lead to erroneous conclusions, hide trends, or introduce bias. Various reasons for rejecting specific data sets are provided and two appendices list accepted and rejected data sources.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Materials Science, Multidisciplinary
Pengfei Wang, Weiqiang Wang, Ming Zhang, Qiwen Zhou, Zengliang Gao
Summary: The effects of specimen size and welded joints on the very high cycle fatigue properties of compressor blade steel KMN-I were studied through ultrasonic fatigue testing. It was found that large specimens exhibited a slow decline in the S-N curve above 10^7 cycles, while welded specimens showed less obvious variations in the very high cycle fatigue characteristics. Metallographic observation and SEM analysis revealed differences in fracture mechanisms between large and welded specimens, with cracks initiating from different sources. Additionally, the formation mechanism of GBF was analyzed, and the predicted fatigue strength and life were consistent with experimental results.
Review
Materials Science, Multidisciplinary
Pedro R. Costa, Luis Reis, Manuel Freitas
Summary: Fatigue damage has a significant impact on the lifespan of mechanical components and structures, and most structural failures are caused by fatigue. The conventional fatigue testing using uniaxial loads does not reflect the multiaxial stresses in real structures. In order to meet the growing demand for longer lifespans, the study of very high cycle fatigue (VHCF) beyond 10E07 to 10E10 cycles has attracted attention. However, traditional fatigue machines are time-consuming and costly for such a high number of cycles. The introduction of high frequency ultrasonic machines has greatly improved the efficiency and reduced the cost of fatigue testing.
MATERIALS PERFORMANCE AND CHARACTERIZATION
(2023)
Article
Mechanics
Han Wu, Chengqi Sun, Wei Xu, Xin Chen, Xiaolei Wu
Summary: In this paper, a continuous runout method (CRM) is proposed to evaluate the fatigue strength in high cycle and very high cycle fatigue regimes based on the probability and statistics theory. The CRM features the simultaneous testing of multiple samples, which reduces the testing period to 1/5-1/3 of that by the common up-and-down method for 16 samples. Experimental data for G20Mn5QT steel, 40 Cr steel, and Ti-6Al-4V alloy validate the CRM's predicted lower limits of fatigue strength, which are slightly more conservative than those obtained by the up-and-down method.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
Yoshiyuki Furuya, Yoshinobu Shimamura, Masahiro Takanashi, Takeshi Ogawa
Summary: This article introduces the standardization of the ultrasonic fatigue testing method in the Japan Welding Engineering Society, covering the testing scope, specimen shapes, and data interpretation. The research suggests that ultrasonic fatigue testing is suitable for high-strength materials but not for low-strength materials.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Engineering, Mechanical
Jie Wan, Jiucheng Zhao, Liming Zhou, Shizhong Zhang, Hongwei Zhao
Summary: In this study, a new cantilever specimen and methodology based on the Timoshenko beam theory and the transfer matrix method were proposed for bending ultrasonic fatigue testing in the VHCF regime. The results of Finite Element Analysis and experimental results from Ti-6Al-4V specimens demonstrate the feasibility and applicability of this methodology for deep research on the bending fatigue behaviors of rotor blade materials.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
H. Heyraud, C. Robert, C. Mareau, D. Bellett, F. Morel, N. Belhomme, O. Dore
Summary: A numerical two-scale approach is proposed to calculate non-local multiaxial equivalent stress at the weld toe and root of welded structures. The method is shown to be robust in different geometries and loading cases, with parameters not significantly affecting stiffness behavior. This approach shows promise for fatigue design of welded structures when compared to full solid finite element models.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Mechanical
Pedro R. da Costa, Luis Reis, Manuel Freitas
Summary: Ultrasonic fatigue testing is a method that uses resonance to achieve very high cyclic load frequencies for studying high cycle fatigue. This study modified the geometry of the specimen and conducted numerical and experimental modal behavior analysis to achieve reliable multiaxial fatigue testing. The results prove a clear trend in crack propagation details with the increase of the induced stress ratio.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Diogo Pereira, Frederico P. D. Alves, Luis Reis, Marco Leite, Augusto M. Deus, Manuel Sardinha, M. Fatima Vaz
Summary: Sandwich panels, consisting of a core and two layers, have a wide range of applications and their mechanical properties are influenced by the geometry of the core. This study investigates the performance of body- and face-centred parallelepiped with struts in z-axis structure by changing its dimensions and relative density, and the results show that the dimensions of the struts and the relative density affect the mechanical performance and failure modes of the panels.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS
(2023)
Article
Energy & Fuels
Mario Vieira, Brian Snyder, Elsa Henriques, Craig White, Luis Reis
Summary: Offshore wind energy is a promising renewable source that can contribute to energy independence, but it requires cost reduction strategies for future development. This study evaluates the viability of structural health monitoring (SHM) systems on the support structures of bottom-fixed offshore wind (BFOSW) and their impact on the farm's life-cycle. Results show that implementing SHM systems can shift maintenance strategies and extend the operational life of the farm.
Review
Materials Science, Multidisciplinary
Manuel Sardinha, M. Fatima Vaz, Tania R. P. Ramos, Luis Reis
Summary: The interest in airless or non-pneumatic tire (NPT) structures emerges due to potential performance and environmental advantages. However, large-scale production of NPTs for most applications is not yet established. This study provides an in-depth review of the mechanical design and development of NPTs, discusses key research areas, and highlights the need for further investigation in the production, performance, and reliability of NPTs.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Felipe Klein Fiorentin, Luis Reis, Grzegorz Lesiuk, Ana Reis, Abilio de Jesus
Summary: A trend of increasing excitation frequencies in fatigue testing has been observed due to advances in control and excitation systems. While high testing frequencies save time and money, they also pose challenges for measurement systems and temperature control. Being able to predict and control sample temperature is essential in high frequency fatigue testing.
Article
Crystallography
Vitor Anes, Rogerio Moreira, Luis Reis, Manuel Freitas
Summary: Under strain control tests and cyclic loading, extruded magnesium alloys exhibit a special mechanism of plastic deformation called twinning and de-twining. This behavior cannot be fully characterized with traditional numerical tools used for steels or aluminum alloys. To address this, a new phenomenological model called hypo-strain has been developed to accurately predict the cyclic stress-strain evolution of magnesium alloys. This study aims to describe the local cyclic elastic-plastic behavior of AZ31B-F magnesium alloy under multiaxial cyclic loading using Abaqus incremental plasticity with the implementation of the hypo-strain model in the UMAT subroutine of Abaqus/Standard.
Article
Crystallography
Vitor Anes, Francisco Bumba, Luis Reis, Manuel Freitas
Summary: In this study, the multiaxial fatigue behavior of the magnesium alloy AZ31BF under proportional and non-proportional loads was investigated. Experimental tests were conducted according to the ASTM E466 protocol to determine the relationship between the fatigue strength of the alloy under these two loading types. The results showed that the fatigue strength of the AZ31BF alloy varies depending on the loading type. Parameter Y was introduced to represent the variation in non-proportional damage and can be used to enhance multiaxial fatigue models that currently overlook the distinction between these loading types.
Article
Engineering, Mechanical
Alexandra A. Arbex, Luis Reis, Gisele F. C. Almeida, Abrao C. Merij, Marcos Massi, Antonio A. Couto
Summary: This study aimed to investigate the influence of coating a thin film of Silicon Carbide and chromium interlayer on the fatigue behavior and failure evaluation of Ti-6Al-4V alloy. The characterization of the layer included roughness, thickness, and adhesion measurements. Uni-axial fatigue tests were conducted under R = 0.1, and SEM was used to observe and identify the fracture surfaces and failure mechanisms. Coated specimens using the DC source exhibited an increased number of cycles to failure, with crack initiation occurring internally rather than superficially. The layer remained adhered to the specimens even after the tests, indicating its effectiveness. In contrast, specimens coated using the HiPIMS source showed a decreased number of cycles to failure, predominantly superficial cracks, and reduced adhesion of the deposited film, proving to be ineffective and worsening the material's fatigue behavior.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Mechanical
Pedro R. da Costa, Masoud Rahaeifard, Diogo Montalva, Luis Reis, Manuel Freitas
Summary: Ultrasonic fatigue specimens require rigorous design to ensure resonance vibration at high frequencies and desired mode shapes. Existing analytical methods for uniaxial tension-compression or pure torsion specimens limit the range of experiments. This paper proposes a semi-analytical formulation for complex ultrasonic specimen geometries under multiaxial tension-torsion, showing good correlation with numerical simulations. This work can facilitate the design and conduct of more varied and efficient ultrasonic fatigue experiments.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
M. C. Salama, F. Alves, L. Reis, A. M. Deus, M. B. Silva, C. Santos, M. J. Carmezim, M. F. Vaz
Summary: Biodegradable metals, particularly iron, have potential as temporary bone implants, but have drawbacks such as high stiffness and low degradation rate. The use of porous materials can overcome these disadvantages by decreasing strength and increasing degradation rate. This study aimed to develop iron porous structures with adequate mechanical and corrosion performance. Three types of structures were studied, and results showed that both mechanical and corrosion properties depended on relative density and pore arrangement. Structures with low relative density exhibited similar compressive strength to human trabecular bone and degradation rates suitable for bone substitutes.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS
(2023)
Review
Materials Science, Multidisciplinary
Francisco Bumba, Paulo Morais, Rodolfo Batalha, Vitor Anes, Luis Reis
Summary: The ability to manufacture complex parts directly from CAD models has attracted attention in the industry. However, issues such as high residual stresses, cracks, and voids in components produced using additive manufacturing have led to the development of post-treatment techniques, with laser shock peening (LSP) considered as one of the most efficient methods. Optimization of LSP parameters remains a challenge, requiring further studies.
Article
Chemistry, Multidisciplinary
Vitor Anes, Cristina B. Neves, Valeria Bostan, Sergio B. Goncalves, Luis Reis
Summary: The aim of this study was to evaluate the retention forces of digitally fabricated removable partial denture clasps over time. The teeth were digitized using a laboratory scanner and two types of clasps were designed and fabricated using a direct laser sintering process. A total of 20,000 cycles of clasp insertion and removal were performed, and the retention forces were recorded. Statistical analysis showed that there were no significant differences in the retention forces between the two types of clasps in most cycles.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Mechanical
Miloslav Kepka, Miloslav Kepka Jr, Radovan Minich
Summary: This paper focuses on the fatigue life evaluation of the bodywork of a new articulated electric (battery) bus. The findings resulted in recommendations to improve the operational reliability of a particular vehicle and provided challenges for future research.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
T. Dusautoir, B. Berthel, S. Fouvry, P. Matzen, K-D. Meck
Summary: This study investigates the impact of post-processing treatments on the fatigue limit of additive manufactured Ti-6Al-4V under stress gradients, with a focus on surface integrity.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Zhuofan Xia, Di Wu, Xiaochen Zhang, Jianqiu Wang, En -Hou Han
Summary: The study reveals the surface-initiated rolling contact fatigue (RCF) failure mechanism under heavy load and initial high roughness surface. The results indicate that precursor of collapsed morphology and nanocrystalline layer are the main factors causing lower RCF life with high roughness compared to low roughness surfaces. The spalling failure initiating from low roughness surface under heavy load is strongly dependent on surface plastic deformation.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Daniel Gren, Knut Andreas Meyer
Summary: Rolling contact loading can cause plastic deformation and fatigue cracks. Current rail standards do not consider the effect of plasticity on mechanical behavior. This study proposes a new method for evaluating the fatigue life of deformed material and finds that superimposed compressive axial loads can increase fatigue life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
R. Kumar, S. Sanyal, J. Bhagyaraj, E. Hari Krishna, S. Mukherjee, K. Prasad, S. Mandal
Summary: This study investigates the thermomechanical fatigue (TMF) behavior of Timetal 834 alloy under different loading conditions. The results show that the alloy exhibits different cyclic hardening and softening responses at different strain amplitudes. The strain amplitude and phase angle have significant effects on the TMF life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Kai Donnerbauer, Tobias Bill, Peter Starke, Ruth Acosta, Bharath Yerrapa, Christian Boller, Klaus Heckmann, Frank Walther
Summary: Given the aging of nuclear power plants, it is important to develop methods for evaluating the integrity of components and structures in nuclear engineering. Suitable nondestructive testing methods can detect material degradation and determine its fatigue life. This study utilized various NDT parameters and scanning electron microscopic methods to explore the relationship between microstructure evolution and NDT data.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Liuyong He, Jiang Zheng, Tianjiao Li, Houkun Zhou, Lihong Xia, Bin Jiang
Summary: This study quantitatively analyzed the effects of precipitates on the deformation mode, cracking mode, and mechanical behavior of WE54 magnesium alloy during low-cycle fatigue. It was found that precipitates promoted the activation of dislocation slip and suppressed the activation of twinning, affecting the cracking mode and mechanical behavior.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Xiangkang Zeng, Conghui Zhang, Wenguang Zhu, Mingliang Zhu, Tongguang Zhai, Xiaomei He, Kangkai Song, Zhuohang Xie
Summary: The cyclic deformation behaviors and damage mechanisms of pure Zr were investigated. The cyclic stress response was mainly influenced by substructure evolutions. Prismatic < a > dislocation slip was identified as the dominant deformation mechanism. Fatigue damage was not only influenced by the initial texture, but also other factors.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Jingyu Yang, Bingbing Li, Yiming Zheng, Gang Chen, Xu Chen
Summary: Heat treatment is used to improve the low-cycle fatigue performance of additive manufactured 316LN stainless steel. The heat-treated material demonstrates initially cyclic hardening followed by softening behavior, and shows a stronger resistance to crack propagation compared to the as-built material, resulting in a longer fatigue life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Lang Zou, Dongfang Zeng, Xiong Chen, Jun Li, Hai Zhao, Liantao Lu
Summary: This study investigates the competitive relationship between fretting fatigue and plain fatigue in press-fitted railway axles. By changing the depth of the stress relief groove, the plain fatigue limit and fretting fatigue strength were tested. Detailed information was gathered, and an evaluation methodology integrating finite element simulation and the Modified Wohler Curve Method was established. The study concludes that the optimal groove depth, which balances the anti-fatigue capabilities, depends on the number of test cycles.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Davide Leonetti, Koji Kinoshita, Yukina Takai, Alain Nussbaumer
Summary: This paper investigates the fatigue behavior of non-load-carrying transverse welded steel attachments, including fatigue crack monitoring and fracture surface analysis under constant and variable amplitude loading. A procedure is proposed to obtain a Markov transition matrix based on the measured strain signal and to randomly resample the stress history for variable amplitude fatigue tests.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Zhe Zhang, Bing Yang, Yuedong Wang, Shoune Xiao
Summary: This paper presents a method for designing fatigue life prediction models with small sample sizes by handling limited sample data. The method integrates the equivalent structural stress method with the maximum likelihood estimation method and adds reliability verification, resulting in enhanced goodness of fit, stability, and optimized sample quantity.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Cooper K. Hansen, Gary F. Whelan, Jacob D. Hochhalter
Summary: This paper presents a method to address the computational demand issue of computing FIPs using CPFEM by developing an interpretable machine learning model. Genetic programming is used to evolve interpretable expressions of FIPs from microstructure features, and these models can serve as efficient substitutes for CPFEM and be easily integrated into engineering workflows.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Luca Susmel
Summary: This paper discusses the problem of estimating notch fatigue limits using machine learning. The results show that machine learning is a promising approach for designing notched components against fatigue. The accuracy in estimating the fatigue limit can be increased by increasing the size and quality of the calibration dataset, as well as including additional input features.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Kefeng Gao, Guoqi Tan, Yanyan Liu, Qiang Wang, Qian Tang, Xuegang Wang, Qiqiang Duan, Zengqian Liu, Zhe Yi, Zhefeng Zhang
Summary: Bioinspired architectures have significant effects on material enhancement. This study investigates the fatigue properties of bioinspired ceramic-polymer composites and natural nacre, revealing the close relationship between architectural types, orientations, fatigue performance, and damage mechanisms.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)