Article
Engineering, Mechanical
Alparslan Solak, Birgul Ascioglu Temiztas, Berna Bolat
Summary: This study proposes a honeycomb with a sine waveform to increase the impact resistance against bird strike on the vertical stabilizer leading edge. Experimental and numerical analysis were conducted to validate the model, and the results show that the honeycomb with a sine waveform can improve the deformation and resistance to bird strike, which is important for the field.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2023)
Article
Engineering, Mechanical
Junbo Yan, Yan Liu, Zichen Yan, Fan Bai, Zhenqing Shi, Peng Si, Fenglei Huang
Summary: This study demonstrated the advantages of auxetic honeycomb sandwich panels in terms of ballistic impact performance. Through experiments and numerical modeling, it was found that the honeycomb core type, unit cell angle, and face-sheets material have significant influences on ballistic resistance, improving the material's ballistic impact performance.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Review
Engineering, Aerospace
M. Guida, F. Marulo, F. Z. Belkhelfa, P. Russo
Summary: This paper aims to study the phenomenon of bird strike at each phase of impact and presents a numerical model for predicting bird strike. The Smooth Particle Hydrodynamics (SPH) bird model is developed and validated based on experiments, allowing for the design of critical components of aircraft structures to be in compliance with aviation airworthiness requirements.
PROGRESS IN AEROSPACE SCIENCES
(2022)
Article
Engineering, Civil
Yile Zhang, Yadong Zhou
Summary: Bird strike is a significant threat to aircraft safety. This study investigates the bird impact resistance of composite sandwich curved plates using the Finite Element Method and Smoothed Particle Hydrodynamics. The results show that the lattice core sandwich structure enhances the impact resistance of composite materials.
THIN-WALLED STRUCTURES
(2023)
Article
Engineering, Multidisciplinary
Yi-tao Wang, Yu-ting He, Teng Zhang, Xiang-hong Fan, Tian-yu Zhang
Summary: This paper establishes a fragmented field of a prefabricated fragment warhead and simulates the intersection of the aircraft and the fragment field under dynamic conditions to determine the distribution of vulnerable parts. High-velocity impact tests were conducted on structural characteristic test pieces of vulnerable parts using a two-stage light-gas gun. A numerical simulation model with a high reduction degree was established using the FEM-SPH self-adaptive method. The damage mode of high-velocity prefabricated spherical fragments on typical vulnerable structures, especially the characteristics of secondary damage caused by debris clouds, was studied. This paper verifies the feasibility of methods for aircraft vulnerable structure distribution and serves as an analysis tool in specific aircraft design and damage mode analysis under different threat sources.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Materials Science, Composites
Sho Kajihara, Ryo Higuchi, Takahira Aoki, Shinya Fukushige
Summary: This paper investigates the peripheral fracture of composite fan blades made of CFRP under bird strike by developing a finite element analysis model. The analysis reveals the vibration behavior and strain distribution of the fan blades, which are influenced by the impact location and rotation.
ADVANCED COMPOSITE MATERIALS
(2023)
Article
Mechanics
Rajendra Prasad Bohara, Steven Linforth, Abdallah Ghazlan, Tuan Nguyen, Alex Remennikov, Tuan Ngo
Summary: This study analyzed the protective effect of a re-entrant auxetic honeycomb-core sandwich panel on reinforced concrete slabs under high explosive detonations using numerical models. The results showed that the AHSP had higher energy absorption and pressure deflection capabilities compared to the CHSP, making it more effective in protecting structures.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Manufacturing
Fatima-Zohra Belkhelfa, Salah Boukraa
Summary: This paper presents an analysis of birdstrikes on the leading edge of an aircraft using the SPH bird impacts model. The study focuses on three different configurations of the leading edge's layups and presents a methodology for certifying aircraft compliance with birdstrike requirements. The results obtained from simulations, including displacements, stress distribution, and damage predictions, were validated through experimental results. This study provides valuable insights for the initial design phase and certification of aeronautical structures.
INTERNATIONAL JOURNAL OF CRASHWORTHINESS
(2022)
Article
Chemistry, Multidisciplinary
Bin Wu, Reza Hedayati, Zhehua Li, Mahsa Aghajanpour, Guichang Zhang, Junhong Zhang, Jiewei Lin
Summary: This study used an SPH mallard bird model to simulate bird impact to rotary aero-engine fan blades and investigated the effects of various impact and bearing parameters. The results showed that impact location and bird orientation significantly influence the bird strike outcomes, with bird impact to blade roots being the most dangerous scenario.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Mechanical
Radoslaw Konik, Christos Kassapoglou, Dean Nguyen
Summary: "This study presents a non-linear energy-based analytical approach to design flat sandwich panels resistant to bird strike. The approach is complemented by numerical simulation using smooth particle hydrodynamics and a non-linear stress-strain model. The designed panels were tested using gelatin birds, and the analytical and numerical approaches showed conservative predictions compared to the actual tests. The numerical analysis accurately predicted the maximum deflection and strains, but had significant deviations after the first peak was reached."
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2023)
Article
Construction & Building Technology
Nguyen-Vu Luat, Hongseok Lee, Jiuk Shin, Ji-Hun Park, Tae-Sang Ahn, Kihak Lee
Summary: This paper presents a new method for enhancing existing RC frames by using the HSRM system. Experimental and numerical investigations showed that the retrofitted RC frame performed better in terms of stiffness, load-bearing capacity, and energy dissipation compared to the non-retrofitted frame. The numerical simulation verified the experimental findings, indicating the FE models can accurately simulate the seismic behaviors of RC frames with HSRM.
STEEL AND COMPOSITE STRUCTURES
(2022)
Article
Engineering, Aerospace
Navya Gara, Velmurugan Ramachandran, Jayaganthan Rengaswamy
Summary: The present study uses FEM analysis to investigate the impact behavior and ballistic resistance of Al 2024-T3 alloy under different impact velocities and target thicknesses. The results suggest that the alloy exhibits the highest energy absorption behavior under specific impact velocity and thickness conditions.
Article
Engineering, Aerospace
Jun Liu, Chunyang Zhang, Bopeng Juan, Zhenhua LI, Chao Zhang, Yulong LI
Summary: This paper presents a study on the damage sensitivity of a wing-type leading edge structure under bird strikes. Through bird strike tests and finite element simulations, the bird strike resistances of an original structure and an improved structure were compared. The results show that the improved structure is less damaged under bird strike and meets the anti-bird strike airworthiness requirements.
CHINESE JOURNAL OF AERONAUTICS
(2023)
Article
Engineering, Aerospace
R. M. Faergestad, J. K. Holmen, T. Berstad, T. Cardone, K. A. Ford, T. Borvik
Summary: Hypervelocity impacts (HVIs) caused by orbital debris pose an increasing threat to spacecraft in low Earth orbit, highlighting the need for effective shielding. This study used a coupled finite element-discrete element method (FEM/DEM) to model HVIs on debris shields. Experimental data was used to validate the results, and simulations were conducted to study the formation of debris clouds and investigate key model parameters.
Article
Chemistry, Multidisciplinary
Bin Wu, Jiewei Lin, Reza Hedayati, Guichang Zhang, Junhong Zhang, Lipeng Zhang
Summary: The study investigated the impact of bird strikes on the rotor system of an aircraft engine, showing that bird strikes lead to transient shocks in the rotor system, resulting in sharp increases in displacement and vibration amplitude. The dynamics of the rotor system transition from stable periodic motion to irregular quasi-periodic motion after a bird strike, with resonance being a possible outcome that may damage the engine. The study also found that the impact force and effects on the rotor system increase with engine rotational speed, with higher speeds resulting in larger peak forces and more peaks in the force curve.
APPLIED SCIENCES-BASEL
(2021)
Review
Materials Science, Composites
E. Giannaros, T. Kotzakolios, V. Kostopoulos
JOURNAL OF COMPOSITE MATERIALS
(2016)
Article
Mechanics
T. Kotzakolios, D. E. Vlachos, V. Kostopoulos
COMPOSITE STRUCTURES
(2011)
Article
Mechanics
E. Giannaros, A. Kotzakolios, G. Sotiriadis, S. Tsantzalis, V Kostopoulos
COMPOSITE STRUCTURES
(2018)
Article
Engineering, Mechanical
E. Giannaros, A. Kotzakolios, V. Kostopoulos, G. Campoli
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2019)
Article
Materials Science, Composites
T. Kotzakolios, D. E. Vlachos, V. Kostopoulos
PLASTICS RUBBER AND COMPOSITES
(2011)
Article
Materials Science, Composites
Efthimios Giannaros, Athanasios Kotzakolios, George Sotiriadis, Vassilis Kostopoulos
Summary: This study proposed a calibration routine to optimize material model parameters and simplify the parameter determination process. By comparing numerical and experimental data, the difference percentage between simulation and experiment was significantly reduced, with good accuracy achieved under both low-velocity and high-velocity impact conditions.
JOURNAL OF COMPOSITE MATERIALS
(2021)
Article
Mechanics
E. Giannaros, P. Gkertzos, A. Kotzakolios, V Kostopoulos
Summary: The study investigates a continuum equivalent finite element model for analyzing the response of fabric material in a jet engine containment to high-velocity impact. The main goal is to minimize computational cost while maintaining accuracy close to that of mesoscale modeling, aiding in the design of large protection systems made of fabric materials. The proposed methodology reduces computational cost by over 400 times with less than 6% accuracy loss, and is validated through simulation of conventional metallic engine containment unit and fabric-reinforced one to fan blade-out loading.
COMPOSITE STRUCTURES
(2021)
Article
Mechanics
Spyridon Kilimtzidis, Athanasios Kotzakolios, Vassilis Kostopoulos
Summary: A new optimization framework is proposed to optimize the composite materials aircraft wings based on low-cost numerical tools for stiffness, strength, and dynamic aeroelastic constraints. The developed framework successfully guides the mass of the wing to a minimum while satisfying the constraints under a critical loading scenario. The presented optimization framework exhibits high accuracy and efficiency, providing a robust numerical tool for the early design stages of composite aircraft wings.
COMPOSITE STRUCTURES
(2023)
Article
Chemistry, Analytical
Ioannis Katsidimas, Vassilis Kostopoulos, Thanasis Kotzakolios, Sotiris E. E. Nikoletseas, Stefanos H. H. Panagiotou, Constantinos Tsakonas
Summary: Recent advances in hardware and software have allowed for the development of embedded intelligence in IoT devices, enabling machine learning and decision-making integration. The proposed extreme-edge system addresses structural health monitoring by using a low-cost device and a methodology that does not rely on specific material or sensor location attributes. By implementing TinyML technology and utilizing random forest and shallow neural network models, the system achieves over 90% accuracy in real-time impact localization.
Article
Engineering, Aerospace
Angelos Kafkas, Spyridon Kilimtzidis, Athanasios Kotzakolios, Vassilis Kostopoulos, George Lampeas
Summary: Efficient optimization is crucial in realizing the full potential of an aeronautical structure, with success depending on capturing all relevant physics and computational efficiency. A multi-fidelity optimization framework was developed in this research to combine low-fidelity modules for initial design optimization and high-fidelity modules to explore further performance gains.
Proceedings Paper
Computer Science, Hardware & Architecture
Gabriel Filios, Ioannis Katsidimas, Vassilis Kostopoulos, Thanasis Kotzakolios, Sotiris Nikoletseas, George Sotiriadis, Ioannis Tsenempis
2019 15TH INTERNATIONAL CONFERENCE ON DISTRIBUTED COMPUTING IN SENSOR SYSTEMS (DCOSS)
(2019)
Article
Engineering, Multidisciplinary
C. Kostagiannakopoulou, X. Tsilimigkra, G. Sotiriadis, V. Kostopoulos
COMPOSITES PART B-ENGINEERING
(2017)
Article
Engineering, Multidisciplinary
E. Giannaros, T. Kotzakolios, S. Tsantzalis, V. Kostopoulos
COMPOSITES PART B-ENGINEERING
(2017)
Article
Engineering, Mechanical
A. P. Simonov, I. V. Sergeichev
Summary: The direct impact method provides a higher sample deformation rate and reliable results for materials with low yield strength and hardening rate. This study proposes an alternative procedure for calculating the strain rate in order to improve accuracy of the direct impact method for a wide range of metals and alloys. The proposed method has been validated through finite element analysis and direct impact tests, and it qualitatively changes the shape of the stress-strain curve by adding an unloading area.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Qiang Wei, Zifeng Li
Summary: This study investigates the dynamic bifurcation of a column when it impacts a rigid plane vertically, which is different from the classical Eulerian static buckling. The findings show that either the dimensionless critical buckling time or the dimensionless critical buckling velocity can be used to determine whether buckling has occurred. Different dimensionless initial defects in the column result in different dimensionless displacement responses, and the nonlinear effect influences the analysis results.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
M. C. Price, M. J. Cole, K. H. Harriss, L. S. Alesbrook, M. J. Burchell, P. J. Wozniakiewicz
Summary: This article introduces a new gas gun developed at the Centre for Astrophysics and Planetary Science, University of Kent, which can produce vertical impacts at speeds up to 2 km/s. The gun design, assembly, operation, and ancillary components are described in detail. The experimental results demonstrate that the gun performs as expected.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Fanny Gant, Gabriel Seisson, Patrice Longere, Skander El Mai, Jean-Luc Zinszner
Summary: The article investigates the high strain rate response of metals and alloys under radial expansion and compares different materials. The results show that different materials exhibit different responses in terms of deformation and fracture.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
M. D. Fitzgerald, J. D. Pecover, N. Petrinic, D. E. Eakins
Summary: This study investigates the mechanism for the destruction of thick flyers accelerated using electric guns and proposes strategies for mitigating their break-up based on experimental results and mathematical models. The findings suggest that limiting the maximum pressure within the flyer and extending the current rise time can prevent flyer failure, increasing the efficiency and shock duration of the electric gun.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Guowen Gao, Enling Tang, Guolai Yang, Yafei Han, Mengzhou Chang, Kai Guo, Liping He
Summary: In this study, the dynamic constitutive model of Al/Ep/W material was investigated and verified through experiments and numerical simulations. The proposed model accurately described the mechanical behavior of the material under high strain rates, providing an important reference for evaluating the response characteristics of the new energetic material projectile to lightweight aluminum armor.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Minzu Liang, Meng Zhou, Xiangyu Li, Yuliang Lin, Fangyun Lu
Summary: UHMWPE fiber mesh reinforced polyurea composites improve structural strength and blast resistance performance, and can alter the failure mode. Loose filler is generated as polyurea melts and fragments penetrate. Joint loads are classified into three categories based on their connection and duration.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Ashutosh Jha, Guglielmo Cimolai, Iman Dayyani
Summary: The present article introduces the Zero Poisson's Ratio Fish Cells metamaterial and investigates the effects of Poisson's ratio on the crashworthiness of different lattice structures. Numerical results demonstrate that the Zero Poisson's Ratio model possesses greater stability and structural integrity with minimal edge deformations.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Hongbo Zhang, Dayong Hu, Xubin Ye, Xin Chen, Yuhuai He
Summary: This study investigated the impact of spherical foreign objects on simulated blade edges through experimental and theoretical analysis. The experimental results showed that increasing impact energy resulted in larger damage sizes, and three distinct types of deformations were observed in FOD. Accurate FOD prediction models were developed using linear and power formulas. The theoretical analysis using a spring-mass system based on Winkler's elastic-plastic foundation theory yielded results in good agreement with experimental measurements, providing a reference for fatigue life assessment of aeroengine blades.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
L. M. Reitter, Y. A. Malik, A. B. Jahn, I. V. Roisman, J. Hussong
Summary: This study characterizes the dynamic strength of wet granular ice layers through impact tests. The results reveal strong connections between ice particles in ice layers generated by ice crystal accretion. Comparable strength values can be obtained by reinforcing ice particle connections in ice layers prepared in the laboratory.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Kyle Mao, Genevieve Toussaint, Alexandra Komrakova, James D. Hogan
Summary: In this study, the Generalized Incremental Stress State dependent damage MOdel (GISSMO) is used to simulate the high-velocity impact failure of Armox 500T steel. The GISSMO is calibrated and validated using experimental data from the literature, and is then applied to investigate the impact failure behaviors of bi-layered steel systems. The results provide new capabilities and insights for the design of armor structures and evaluation of impact failure behaviors in Armox 500T/RHA bi-layered systems.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Asim Onder
Summary: This paper investigates the performance of bumper plates with wavy surfaces under hypervelocity impact and finds that they are more effective in decreasing the impact energy compared to flat plates. The study also reveals the distinctive debris cloud generation that has never been reported before.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Zhi-Yong Yin, Xiao-wei Chen
Summary: This study numerically reveals three typical fracture modes of explosively-driven metal shells and investigates the influencing factors of different fracture modes through experimental data and dimensional analysis.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Jiri Pachman, David J. Chapman, Marek Foglar, Martin Kunzel, William G. Proud
Summary: Through the study of different types of concrete, it was found that despite their compositional complexity, range of compressive strengths, and reinforcement methods, the average Hugoniot data were remarkably similar between different concrete types.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)
Article
Engineering, Mechanical
Konstantin Kappe, Klaus Hoschke, Werner Riedel, Stefan Hiermaier
Summary: This paper presents a multi-objective optimization procedure for effectively designing gradient lattice structures under dynamic loading. The aim is to maximize energy absorption characteristics and achieve a lightweight design. Through considering design variables such as the relative density and density gradient, the peak crushing force reduction and maximized specific energy absorption are simultaneously optimized. A simplified beam-based finite element model is used to efficiently model and simulate the lattice structures. An artificial neural network is trained to predict energy absorbing characteristics and find optimal lattice structure configurations. The network is trained using a multi response adaptive sampling algorithm, allowing parallel simulation with automatically generated finite element models. A multi-objective genetic algorithm is then used to find optimal combinations of design parameters for lattice structures under different impact velocities and cell topologies.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2024)