Article
Engineering, Mechanical
Zijiao Jia, Marie-Laetitia Pastor, Christian Garnier, Xiaojing Gong
Summary: A new fatigue limit determination method based on thermographic data is proposed in this paper to overcome the limitations of Risitano and Luong's method. The fatigue limit is defined as the maximum stress corresponding to the peak value of the angle change normalized by its amplitude. The evaluation of this method using experimental data of Multidirectional CFRP laminates and literature data for different materials shows that it can effectively determine the fatigue limit of composite laminates regardless of their stacking sequence.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
Tetsuya Matsunaga, Nobuo Nagashima, Shigeaki Sugimoto
Summary: Lock-in infrared thermography was employed to estimate the fatigue limit of Ti-6Al-4V alloy at room temperature by detecting the infrared emitted during cyclic loading. The method separated reversible and irreversible temperature change components to estimate the fatigue limit, which corresponded to results from conventional fatigue tests. A new assessment line was identified in the study, showing a smaller non-failure region compared to the modified Goodman diagram due to the titanium alloy's reduced fatigue limit at near-zero stress ratios.
MATERIALS TRANSACTIONS
(2021)
Article
Physics, Applied
Yuta Kainuma, Ryo Iguchi, Dwi Prananto, Vitaliy I. Vasyuchka, Burkard Hillebrands, Toshu An, Ken-ichi Uchida
Summary: Lock-in thermography measurements were used to study heat source distribution induced by the unidirectional spin-wave heat conveyer effect, showing spatially biased sharp heating patterns and the importance of edge spin-wave dynamics. The capability of remote heating through a macro-scale air gap between two magnetic materials was demonstrated thanks to long-range dipole-dipole coupling.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Zhanqi Liu, Haijiang Wang, Xueting Chen, Wei Wei
Summary: This study aims to develop a theoretical model combined with RVE theory for rapid fatigue limit prediction. It is believed that anelastic and microplastic behaviors contribute to temperature variation in high-cycle fatigue, and a constitutive equation is deduced to relate temperature rise evolution to stress amplitude using the heat balance equation. A method combining statistical analysis with thermographic experimental data is also developed for accurate fatigue limit estimation. Experimental data of metallic specimens and welded joints validate the proposed model, showing good agreement between experimental and predicted data.
Article
Engineering, Mechanical
Florian Schaefer, Jan Rosar, Haoran Wu, Peter Starke, Michael Marx
Summary: The plasticity of metals during fatigue testing generates internal heat, making thermography widely accepted for assessing fatigue damage. A rarely used NTC thermistor temperature measurement technique, proposed 40 years ago, reveals the temperature distribution with higher resolution compared to modern thermographic methods. This simple and cost-effective method enables rapid and efficient assessment of fatigue limits for various materials and conditions.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Materials Science, Characterization & Testing
Tiziana Matarrese, Davide Palumbo, Umberto Galietti
Summary: Lock-in thermography is a well-established technique for investigating fiber-reinforced polymer composite materials. This study aims to compare four well-known lock-in thermography algorithms in the transient regime to evaluate their accuracy and precision in determining defects. Experimental tests on carbon fiber-reinforced polymer test pieces and simulation data were used to analyze the algorithms' performance.
NDT & E INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Ignacio Bustos, Marcos Bergant, Alejandro Yawny
Summary: The suitability of infrared thermography (IRT) for estimating the fatigue limit of Ti-6Al-4V produced by electron beam melting (EBM) is assessed. The IRT-based methods are appropriate for machined and polished HIPed EBM specimens, as well as wrought material, but not for other printed material conditions. This is due to the presence of surface roughness and internal defects that hinder surface thermal manifestation in non HIP treated EBM-produced material.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
Isa Emami Tabrizi, Fatih Ertugrul Oz, Jamal Seyyed Monfared Zanjani, Sefa Kemal Mandal, Mehmet Yildiz
Summary: This study proposes a new method for damage classification and failure sequence evaluation in sandwich panel composite materials under flexural loading condition, utilizing acoustic emission monitoring and lock-in thermography analysis. The combination of interrupted mechanical tests, acoustic emission hits recording, and thermography technique helps in successfully identifying different types of damage and their manifestation sequence during flexural tests.
MECHANICS OF MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
A. Akai, Y. Sato, M. Murase, Y. Kojima, Y. Okubo
Summary: An experimental procedure for uniquely determining the fatigue limit based on temperature second harmonic measurements is developed. The present phase double frequency (2f) lock-in thermography accurately measures the temperature second harmonic amplitude, and the fatigue limit is then uniquely determined based on the generation mechanism of the temperature second harmonic. This procedure effectively eliminates the influence of non-fatigue-related factors and provides reasonable estimation accuracy.
EXPERIMENTAL MECHANICS
(2023)
Article
Chemistry, Multidisciplinary
Takamasa Hirai, Ryo Iguchi, Asuka Miura, Ken-ichi Uchida
Summary: A new method of modulating the elastocaloric temperature change is reported by applying kirigami structures, which can generate focused heat absorption and release, improving local cooling/heating performance.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Engineering, Mechanical
Ali Mahmoudi, Michael M. Khonsari
Summary: This article discusses four different experimental approaches for rapidly estimating the fatigue limit (endurance limit) based on energy dissipation during cyclic loading. These approaches utilize energy dissipation and thermography, and can accurately evaluate the fatigue limit of a material through fatigue testing on a single specimen. The results show that the trend of energy dissipation can be used to predict the fatigue limit by observing changes in released energy due to damage accumulation at stress levels above the fatigue limit. Experimental results on CS 1018 and SS 304 specimens are presented to demonstrate the efficacy of the proposed methods.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Green & Sustainable Science & Technology
Yixuan Jiao, Geonil Lee, Liang Wang, Jung-Hoon Park, Nak-Sam Choi
Summary: In this study, the fatigue limit of STS304 austenitic stainless steel was estimated using thermographic methods at different load frequencies. It was found that using intrinsic dissipated energy as an indicator improved the sensitivity and reliability of fatigue damage.
INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING-GREEN TECHNOLOGY
(2022)
Article
Chemistry, Physical
Lukas Steinmetz, Christoph Geers, Mathias Bonmarin, Barbara Rothen-Rutishauser, Alke Petri-Fink, Marco Lattuada
Summary: The use of plasmonic nanoparticles in biological applications has increased over the past two decades due to their ability to generate heat when exposed to light. Lock-in thermography can efficiently measure the heat produced by these nanoparticles, and a mathematical model based on energy balance using Mie theory can quantitatively predict the heat generation by gold nanoparticles in different concentrations and wavelengths. The model shows a linear increase in temperature response with gold concentration and independence from particle size.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Samuel Klein, Henrique Fernandes, Hans-Georg Herrmann
Summary: This study investigates the application of lock-in thermography for solar loading thermography, highlighting the suitability of calculations based on area sources for large-scale structures. It provides an overview of extended source approximation formulas for determining material properties and demonstrates the practical application in estimating thermal effusivity of a retaining wall structure subject to natural outside heating phenomena.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Physical
Mateu Colom, Javier Rodriguez-Aseguinolaza, Arantza Mendioroz, Agustin Salazar
Summary: A study characterizing a very narrow fatigue crack in an Al-alloy dog bone plate using laser-spot lock-in thermography. Results show the crack has nearly constant depth and width along 0.7 mm length, with fast reduction in both quantities until the crack vanishes. The study demonstrates the ability of laser-spot lock-in thermography to quantitatively characterize narrow cracks, even below 1 µm.
Article
Chemistry, Analytical
Panagiota T. Dalla, Ilias K. Tragazikis, George Trakakis, Costas Galiotis, Konstantinos G. Dassios, Theodore E. Matikas
Summary: Recent findings suggest that carbon nano-species, such as nanotubes and graphene, have the potential to improve the multifunctional properties of cement, including mechanical, fracture mechanical, and electrical properties. Testing on mortars modified with graphene nanoplatelets and carbon nanotubes showed significant improvements in fracture behavior at specific nanofiller concentrations, indicating great potential for smart construction applications.
Article
Chemistry, Multidisciplinary
Ilias K. Tragazikis, Theodoti Z. Kordatou, Dimitrios A. Exarchos, Panagiota T. Dalla, Theodore E. Matikas
Summary: There is a growing need to understand the relationship between construction material properties and behavior with their microstructure, especially in the context of freshly poured cement-based materials. This study focuses on developing a reliable method for monitoring the hydration process in cementitious composites enhanced with carbon nanotubes, utilizing a combination of nonlinear elastic waves, contact ultrasonics, and noncontact optical detection. Changes in material nonlinearity during the hardening process, particularly with increased carbon nanotube concentration, can be detected through the assessment of higher-harmonic amplitudes of an ultrasonic wave, providing valuable insights for structural behavior in the long term.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Elias Ananiadis, Konstantinos T. Argyris, Theodore E. Matikas, Athanasios K. Sfikas, Alexandros E. Karantzalis
Summary: Novel aluminium matrix composites reinforced by MoTaNbVW refractory high-entropy alloy (HEA) particulates were fabricated by powder metallurgy. The composites exhibited low porosity, good homogeneity, few defects, and good distribution of the reinforcing phase in the Al matrix. However, increasing the volume of the reinforcing phase led to increased hardness values, while the Al-HEA composites showed susceptibility to localised forms of corrosion in 3.5% NaCl solution.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Janardhan Padiyar M., Luca Zanotti Fragonara, Ivan Petrunin, Joao Raposo, Antonios Tsourdos, Iain Gray, Spyridoyla Farmaki, Dimitrios Exarchos, Theodore E. Matikas, Konstantinos G. Dassios
Summary: A new method for detecting damage in aircraft composite materials has been developed in this study, utilizing phased-array ultrasonics and infra-red thermography techniques, and achieving satisfactory results on aircraft-grade painted composite materials. The sensor systems have been miniaturized for integration onto a vortex-robotic platform inspector as part of the larger research project, the Horizon-2020 'CompInnova' project.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Anastasios C. Mpalaskas, Theodore E. Matikas, Dimitrios G. Aggelis, Ninel Alver
Summary: The enhancement of ductility and toughness in steel fiber reinforced concrete is attributed to additional fracture mechanisms and overcoming interlocking and adhesion between fibers and the cementitious matrix. Acoustic emission monitoring can provide real-time characterization of material performance, and low load levels of AE behavior are indicative of reinforcement and final mechanical properties.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Marinos Dimitropoulos, George Trakakis, Nikolaus Meyerbroeker, Raphael Gehra, Polina Angelova, Albert Schnieders, Christos Pavlou, Christos Kostaras, Costas Galiotis, Konstantinos Dassios
Summary: Ultrathin carbon nanomembranes (CNMs) are two-dimensional materials with sub-nm intrinsic pores that mimic biofiltration membranes. They exhibit highly selective, permeable, and energy-efficient water separation. This study investigates their mechanical performance and thermal stability using atomic force microscopy (AFM) and tensile testing, and identifies critical parameters affecting their mechanical response.
Proceedings Paper
Engineering, Multidisciplinary
I. K. Tragazikis, T. Z. Kordatou, P. T. Dalla, D. A. Exarchos, T. E. Matikas
Summary: The behavior and properties of construction materials depend largely on their internal microstructure characteristics. Understanding the curing process of freshly poured cementitious materials is crucial for successful construction development. Changes in ultrasonic wave propagation and pulse velocity occur during the solidification of cement-based materials, with the point of solidification affecting load-bearing capacity and long-term behavior.
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2021
(2021)
Proceedings Paper
Engineering, Multidisciplinary
A. C. Mpalaskas, D. G. Aggelis, T. E. Matikas
Summary: This study conducted fracture experiments on fiber reinforced concrete beams to examine the level of restoration using acoustic emission (AE) technique. The specimens were repaired with epoxy resin injection to main macrocracks, showing good insight of microstructure and restoration level.
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2021
(2021)
Proceedings Paper
Engineering, Multidisciplinary
A. C. Mpalaskas, D. G. Aggelis, T. E. Matikas
Summary: This study examines the fracture behavior of mortar specimens modified with waterproofing adhesives using acoustic emission (AE). The results suggest that the use of adhesives in mortars can be successfully characterized by AE and ultrasonic parameters, indicating the value of elastic wave nondestructive evaluation in the building materials sector.
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2021
(2021)
Proceedings Paper
Engineering, Multidisciplinary
P. T. Dalla, I. K. Tragazikis, D. A. Exarchos, T. E. Matikas
Summary: The study aims to investigate the impact of graphene nanoplatelets on the mechanical and electrical properties of cement mortars. Significant improvements in mechanical characteristics and fracture energy were observed at specific graphene loadings, as evaluated by acoustic emission data. Additionally, the electrical response of the graphene-modified cement mortars was studied through electrical conductivity measurements.
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2021
(2021)
Proceedings Paper
Computer Science, Interdisciplinary Applications
A. C. Mpalaskas, T. E. Matikas
SMART STRUCTURES AND NDE FOR INDUSTRY 4.0, SMART CITIES, AND ENERGY SYSTEMS
(2020)
Proceedings Paper
Computer Science, Interdisciplinary Applications
T. Z. Kordatou, A. C. Mpalaskas, T. E. Matikas
SMART STRUCTURES AND NDE FOR INDUSTRY 4.0, SMART CITIES, AND ENERGY SYSTEMS
(2020)
Proceedings Paper
Computer Science, Interdisciplinary Applications
T. Z. Kordatou, A. C. Mpalaskas, I. K. Tragazikis, T. E. Matikas
SMART STRUCTURES AND NDE FOR INDUSTRY 4.0, SMART CITIES, AND ENERGY SYSTEMS
(2020)
Proceedings Paper
Engineering, Multidisciplinary
I. K. Tragazikis, T. Z. Kordatou, A. N. Koutrakou, D. A. Exarchos, P. T. Dalla, T. E. Matikas
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2020
(2020)
Proceedings Paper
Engineering, Multidisciplinary
P. T. Dalla, I. K. Tragazikis, D. A. Exarchos, T. E. Matikas
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2020
(2020)
