Article
Engineering, Mechanical
Weigang Wang, Wei Yang, Chun-Qing Li
Summary: This paper aims to determine a normalized fully plastic J-integral solution to mixed-mode fracture caused by inclined surface cracks, and develops a set of predictive formulas. The study finds that an increase in strain hardening exponent can increase the difference of normalized fully plastic J-integrals in pipes with different wall thicknesses.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Multidisciplinary
Qi Shuang, Xiang WenXin, Cai LiXun, Liu XiaoKun, Shao ChunBing, Ning FangMao, Shi JinHua, Yu WeiWei
Summary: The study introduces a new theoretical method and testing approach for describing mixed-mode I-II crack-based fatigue crack propagation, and develops a novel compliance-based testing method for FCPI-II.
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
(2021)
Article
Engineering, Civil
Jingying Yang, Jiangpeng Shu, Jun Li, Ke Yu, Kamyab Zandi, Yong Bai
Summary: This study investigates the influence of inclined pre-cracks on the shear behavior of reinforced concrete (RC) beams without transverse reinforcement. Experimental results show that inclined pre-cracks in the bending span have minor effects on shear capacity, while pre-cracks near supports within the shear span can significantly reduce the load-bearing capacity of the beams.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Mechanical
Xiangqiao Yan
Summary: The empirical fracture equation for mixed mode crack proposed in this note has been verified to be simple in computation and high in accuracy based on test data from literature.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Engineering, Marine
Bo Zhou, Jie Wang, Guangqiu Jin, Ying Zhou, Xikun Wang, Wie Min Gho
Summary: This paper presents a numerical analysis of the hydrodynamic characteristics and wake structures of an inclined finite cylinder using large eddy simulation (LES). The results show that the hydrodynamic force coefficients and Strouhal number of the inclined cylinder remain constant within a certain range and are smaller than those of the upright case, indicating better structural stability. The wake structures in the lee of the cylinder are dependent on the inclination angle and exhibit different vortex modes at different angles.
Article
Engineering, Geological
Stephen Hedan, Valery Valle, Richard Giot, Philippe Cosenza
Summary: This study explores the mixed-mode behavior of desiccation cracks in a clayey rock gallery and the advances in digital image correlation algorithms that allow for the automatic detection of displacement jumps and sliding of cracks. The results show a linear relationship between solid phase deformation and crack porosity, and indicate that most desiccation cracks evolve in a mixed-mode with comparable shear and opening values.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Engineering, Civil
Hongcan Yao, Ping Tan, T. Y. Yang, Fulin Zhou
Summary: Existing studies on shake table real-time hybrid testing (ST-RTHT) mainly employ displacement-based control methods, which have good tracking for displacement but may have unsatisfactory acceleration tracking. This study introduces a sliding mode acceleration control (SMAC) method to overcome the limitations of traditional sliding mode force control (SMFC). The proposed SMAC does not require information about the force applied by the structure to the shake table and the unmodeled complex nonlinear force.
Article
Engineering, Civil
Pengru Deng, Takashi Matsumoto
Summary: This paper presents a rational method for calculating weight functions of inclined shear cracked RC beams with any geometry using the VCE technique in FEM. The relationships between weight functions and geometric parameters are investigated to study the shear behaviors of a large set of RC beams tested under bending load. The method developed numerically allows for convenient and comprehensive study of shear behaviors following theoretical fracture mechanics approach.
Article
Energy & Fuels
Bin Xu, Shuning Dong, Shangxian Yin, Shuxia Li, Yanling Xu, Zhenxue Dai
Summary: The research demonstrates that the deduced theoretical calculation formula of critical grouting pressure is in agreement with numerical simulation results; when mixed mode I-II fractures initiate, grouting pressure exceeds the perpendicular stress of the overlying rock; greater overlying rock mass density results in higher grouting pressure for fracture initiation; when the side pressure coefficient is >= 1, crack dip angle increases and the grouting pressure for fracture initiation tends to decrease; the empirical grouting pressure at maximum allowable grouting pressure is 2.0-2.5 p(w), which does not lead to propagation and failure of existing cracks.
Article
Engineering, Mechanical
Pengfei Jin, Xin Wang, Haoruo Chen, Zheng Liu, Xu Chen
Summary: This paper investigates the variations of stress field parameters, including stress intensity factors (SIFs), T-stresses, and crack-mouth-opening-displacement (CMOD) compliance, in CTS specimens with slanted propagating cracks through finite element (FE) analysis. The results show that KI, KII, and T11 are greatly influenced by the initial crack length ratio, the slanted propagating crack length ratio, and the loading angle. T33, as an out-of-plane constraint parameter, is subject to the coupling effects of in-plane geometries, out-of-plane geometries, and mixed-mode loading. Moreover, the measurement span has an effect on CMOD-compliance results for CTS specimens under mixed-mode loading, but only within the recommended range. The accuracy of the developed CMOD-compliance equations is validated through fatigue crack growth (FCG) experiments.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Chemistry, Physical
Tong Li, Zhenting Yang, Chenghui Xu, Xinsheng Xu, Zhenhuan Zhou
Summary: In this work, the crack propagation of 2D decagonal QCs is studied using a fracture phase field method. The damage of QCs near the crack is evaluated using a phase field variable, and the crack topology is described by this variable and its gradient. Numerical examples simulate the crack propagation paths of 2D QCs and investigate the effects of the phason field on the crack growth behaviors. The interaction of double cracks in QCs is also discussed.
Article
Engineering, Civil
Cao Yingri, Wang Haishen, Sun Jiangbo, Pan Peng
Summary: This paper presents a novel two-direction shear-force sensor (2D-SFS) for measuring boundary friction force in structural compression-shear tests. The sensor is capable of measuring both friction force and shear force, and enhances test accuracy through horizontal force correction.
ENGINEERING STRUCTURES
(2022)
Article
Mechanics
O. Demir
Summary: In this study, the fracture behavior of different specimen types made of marble and PMMA was analyzed in terms of predicting crack initiation angle. The study showed that cracks can grow in a curvilinear form under different loading conditions, and the recently developed crack deflection angle equation can be used to accurately predict the crack initiation angle.
MECHANICS OF SOLIDS
(2021)
Article
Mechanics
Zelin Liu, Chunde Ma, Xin'ao Wei, Weibin Xie
Summary: The presence of cracks had a weak effect on the strength of sandstone specimens during direct tensile testing (DTT) and uniaxial compression testing (UCT). However, the strengths of the specimens increased gradually with different crack inclinations (fi). The elastic modulus of rock increased with an increase in fi during UCT, while it remained almost unchanged during DTT.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Multidisciplinary
Ruifeng Zheng, Zichen Deng
Summary: This article investigates the penny-shaped and half-plane crack problems in an infinite space of one-dimensional hexagonal quasicrystals. The complete fundamental solutions of the phonon and phason fields are obtained, and important quantities on the crack plane are derived. These fundamental solutions are significant for boundary element analysis and numerical research.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Materials Science, Multidisciplinary
Georgios Kaisarlis, Georgios Vasiliou, Vasileios Spitas, Vassilis Inglezakis, Grigorios Itskos, Christos Spitas
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2019)
Article
Thermodynamics
L. Gkimisis, N. Arapkoules, G. Vasileiou, A. Soldatos, V Spitas
APPLIED THERMAL ENGINEERING
(2020)
Review
Automation & Control Systems
Christos Vakouftsis, Andreas Mavridis-Tourgelis, Georgios Kaisarlis, Christopher G. Provatidis, Vasilios Spitas
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2020)
Article
Automation & Control Systems
Andreas Mavridis-Tourgelis, Christos Vakouftsis, Georgios Kaisarlis, Vaios G. Arampatzis, Christopher G. Provatidis, Vasilios Spitas
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2020)
Article
Engineering, Mechanical
M. M. S. Dwaikat, C. Spitas, V Spitas
Summary: This paper proposed a new model and numerical procedure for achieving hysteretic material damping in the time domain by modifying the viscous model. The superiority of this method lies in its ability to capture material hysteresis without the need for knowledge of the system's natural frequencies or the past time history of the response.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Mechanical
M. M. S. Dwaikat, C. Spitas, V Spitas
Summary: The proposed model captures the weak frequency sensitivity of elastic hysteretic damping for MDOF structures under free or forced vibration. By adjusting the damping coefficient to keep the dissipated energy insensitive to the frequency characteristics, it outperforms other damping models like viscous, Rayleigh, and Reid MDOF models. It does not require extensive calibration or knowledge of motion history.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Mechanical
L. Gkimisis, G. Vasileiou, E. Sakaridis, C. Spitas, V. Spitas
Summary: This study presents an efficient single degree of freedom (SDOF) model that accurately captures the nonlinear characteristics of gear transmissions, including handling of meshing nonlinearities, gear contact reversal, and mesh stiffness modeling. The model allows for accurate numerical solutions and shows high agreement with literature data in both static and dynamic results, while maintaining minimal required pre-calculations and low computational cost.
MECHANISM AND MACHINE THEORY
(2021)
Article
Engineering, Mechanical
Christos Spitas, Mahmoud S. Dwaikat, Vasileios Spitas
Summary: The article presents a SDOF time-domain model for elastic hysteretic damping, with a focus on introducing an instantaneous correction factor recursively dependent on system state variables to achieve weak frequency dependency. Different formulations for calculating the correction factor's impact on predicted hysteresis loops and potential singularities are investigated, alongside plotting hysteresis loops and simulating forced vibration responses to various excitations for comparison with conventional damping models.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2021)
Article
Construction & Building Technology
Efstratios Tsolakis, Christos Kalligeros, Panteleimon Tzouganakis, Dimitrios Koulocheris, Vasilios Spitas
Summary: This article introduces the design of a test device for cryogenic testing of concrete samples and its application, discussing the challenges and solutions. The data obtained from experiments are consistent with results in the literature, indicating the reliability of the test device.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Review
Chemistry, Analytical
Nikolaos Rogkas, Christos Vakouftsis, Vasilios Spitas, Nikos D. Lagaros, Stelios K. Georgantzinos
Summary: This paper reviews the main processes, materials, and applications of microscale AM technology, discusses the future research needs for this technology, and emphasizes the importance of introducing a design methodology.
Proceedings Paper
Engineering, Civil
Nikolaos Rogkas, Georgios Vasileiou, Vasilios Spitas, Ioannis A. Antoniadis
Summary: The Industrial French Wharf of Lavrion, built in 1888, was used for loading and unloading ships carrying mining materials, coal, and commercial products. Different mechanisms were used depending on the type of product, including manual carriage transportation, steam cranes, and a conveyor belt system. The study aims to understand and describe the operation of these loading and unloading mechanisms, as they are of historical and industrial significance.
PROTECTION OF HISTORICAL CONSTRUCTIONS, PROHITECH 2021
(2022)
Article
Engineering, Aerospace
Georgios Ntourmas, Rene Meissner, Vasilios Spitas
JOURNAL OF AIRCRAFT
(2020)
Article
Mechanics
C. Spitas, M. M. S. Dwaikat, V Spitas
ARCHIVES OF MECHANICS
(2020)
Article
Mathematics, Interdisciplinary Applications
Christos Manopoulos, Giannis Savva, Achilleas Tsoukalis, Georgios Vasileiou, Nikolaos Rogkas, Vasilios Spitas, Sokrates Tsangaris
Article
Mathematics, Interdisciplinary Applications
Nikolaos Rogkas, Christos Vakouftsis, Georgios Vasileiou, Christos Manopoulos, Vasilios Spitas
Article
Engineering, Multidisciplinary
Sicheng Jiao, Shixiang Wang, Minge Gao, Min Xu
Summary: This paper presents a non-contact method of thickness measurement for thin-walled rotary shell parts based on a chromatic confocal sensor. The method involves using a flip method to obtain surface profiles from both sides of the workpiece, measuring the decentration and tilt errors of the workpiece using a centering system, establishing a unified reference coordinate system, reconstructing the external and internal surface profiles, and calculating the thickness. Experimental results show that the method can accurately measure the thickness of a sapphire spherical shell workpiece and is consistent with measurements of other materials.
Article
Engineering, Multidisciplinary
Rajeev Kumar, Sajal Agarwal, Sarika Pal, Alka Verma, Yogendra Kumar Prajapati
Summary: This study evaluated the performance of a CaF2-Ag-MXene-based surface plasmon resonance (SPR) sensor at different wavelengths. The results showed that the sensor achieved the maximum sensitivity at a wavelength of 532 nm, and higher sensitivities were obtained at shorter wavelengths at the expense of detection accuracy.
Article
Engineering, Multidisciplinary
Attilio Di Nisio, Gregorio Andria, Francesco Adamo, Daniel Lotano, Filippo Attivissimo
Summary: Capacitive sensing is a widely used technique for a variety of applications, including avionics. However, current industry standard Capacitive Level Sensors (CLSs) used in helicopters perform poorly in terms of sensitivity and dynamic characteristics. In this study, novel geometries were explored and three prototypes were built and tested. Experimental validation showed that the new design featuring a helicoidal slit along the external electrode of the cylindrical probe improved sensitivity, response time, and linearity.
Article
Engineering, Multidisciplinary
Kai Yang, Huiqin Wang, Ke Wang, Fengchen Chen
Summary: This paper proposes an effective measurement method for dynamic compaction construction based on time series model, which enables real-time monitoring and measurement of anomalies and important construction parameters through simulating motion state transformation and running time estimation.
Article
Engineering, Multidisciplinary
Hui Fu, Qinghua Song, Jixiang Gong, Liping Jiang, Zhanqiang Liu, Qiang Luan, Hongsheng Wang
Summary: An automatic detection and pixel-level quantification model based on joint Mask R-CNN and TransUNet is developed to accurately evaluate microcrack damage on the grinding surfaces of engineering ceramics. The model is effectively trained on actual micrograph image dataset using a joint training strategy. The proposed model achieves reliable automatic detection and fine segmentation of microcracks, and a skeleton-based quantification model is also proposed to provide comprehensive and precise measurements of microcrack size.
Review
Engineering, Multidisciplinary
Sang Yeob Kim, Da Yun Kwon, Arum Jang, Young K. Ju, Jong-Sub Lee, Seungkwan Hong
Summary: This paper reviews the categorization and applications of UAV sensors in forensic engineering, with a focus on geotechnical, structural, and water infrastructure fields. It discusses the advantages and disadvantages of sensors with different wavelengths and addresses the challenges of current UAV technology and recommendations for further research in forensic engineering.
Article
Engineering, Multidisciplinary
Anton Nunez-Seoane, Joaquin Martinez-Sanchez, Erik Rua, Pedro Arias
Summary: This article compares the use of Mobile Laser Scanners (MLS) and Aerial Laser Scanners (ALS) for digitizing the road environment and detecting road slopes. The study found that ALS data and its corresponding algorithm achieved better detection and delimitation results compared to MLS. Measuring the road from a terrestrial perspective negatively impacted the detection process, while an aerial perspective allowed for scanning of the entire slope structure.
Article
Engineering, Multidisciplinary
Nur Luqman Saleh, Aduwati Sali, Raja Syamsul Azmir Raja Abdullah, Sharifah M. Syed Ahmad, Jiun Terng Liew, Fazirulhisyam Hashim, Fairuz Abdullah, Nur Emileen Abdul Rashid
Summary: This study introduces an enhanced signal processing scheme for detecting mouth-click signals used by blind individuals. By utilizing additional band-pass filtering and other steps, the detection accuracy is improved. Experimental results using artificial signal data showed a 100% success rate in detecting obstacles. The emerging concepts in this research are expected to benefit radar and sonar system applications.
Article
Engineering, Multidisciplinary
Jiqiang Tang, Shengjie Qiu, Lu Zhang, Jinji Sun, Xinxiu Zhou
Summary: This paper studies the magnetic noise level of a compact high-performance magnetically shielded room (MSR) under different operational conditions and establishes a quantitative model for magnetic noise calculation. Verification experiments show the effectiveness of the proposed method.
Review
Engineering, Multidisciplinary
Krzysztof Bartnik, Marcin Koba, Mateusz Smietana
Summary: The demand for miniaturized sensors in the biomedical industry is increasing, and optical fiber sensors (OFSs) are gaining popularity due to their small size, flexibility, and biocompatibility. This study reviews various OFS designs tested in vivo and identifies future perspectives and challenges for OFS technology development from a user perspective.
Article
Engineering, Multidisciplinary
Yue Wang, Lei Zhou, Zihao Li, Jun Wang, Xuangou Wu, Xiangjun Wang, Lei Hu
Summary: This paper presents a 3-D reconstruction method for dynamic stereo vision of metal surface based on line structured light, overcoming the limitation of the measurement range of static stereo vision. The proposed method uses joint calibration and global optimization to accurately reconstruct the 3-D coordinates of the line structured light fringe, improving the reconstruction accuracy.
Article
Engineering, Multidisciplinary
Jaafar Alsalaet
Summary: Order tracking analysis is an effective tool for machinery fault diagnosis and operational modal analysis. This study presents a new formulation for the data equation of the second-generation Vold-Kalman filter, using separated cosine and sine kernels to minimize error and provide smoother envelopes. The proposed method achieves high accuracy even with small weighting factors.
Article
Engineering, Multidisciplinary
Tonglei Cao, Kechen Song, Likun Xu, Hu Feng, Yunhui Yan, Jingbo Guo
Summary: This study constructs a high-resolution dataset for surface defects in ceramic tiles and addresses the scale and quantity differences in defect distribution. An improved approach is proposed by introducing a content-aware feature recombination method and a dynamic attention mechanism. Experimental results demonstrate the superior accuracy and efficiency of the proposed method.
Article
Engineering, Multidisciplinary
Qinghong Fu, Yunxi Lou, Jianghui Deng, Xin Qiu, Xianhua Chen
Summary: Measurement and quantitative characterization of aging-induced gradient properties is crucial for accurate analysis and design of asphalt pavement. This research proposes the composite specimen method to obtain asphalt binders at different depths within the mixture and uses dynamic shear rheometer tests to measure aging-induced gradient properties and reveal internal mechanisms. G* master curves are constructed to investigate gradient aging effects in a wide range. The study finds that the composite specimen method can effectively restore the boundary conditions and that it is feasible to study gradient aging characteristics within the asphalt mixture. The study also observes variations in G* and delta values and the depth range of gradient aging effects for different aging levels.
Article
Engineering, Multidisciplinary
Min Li, Kai Wei, Tianhe Xu, Yali Shi, Dixing Wang
Summary: Due to the limitations of ground monitoring stations in China for the BDS, the accuracy of BDS Medium Earth Orbit (MEO) satellite orbits can be influenced. To overcome this, low Earth orbit (LEO) satellites can be used as additional monitoring stations. In this study, data from two LEO satellites were collected to improve the precise orbit determination of the BDS. By comparing the results with GPS and BDS-2/3 solutions, it was found that including the LEO satellites significantly improved the accuracy of GPS and BDS-2/3 orbits.
