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Advanced composite armor protection systems for military vehicles: design methodology, ballistic testing, and comparison

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COMPOSITES SCIENCE AND TECHNOLOGY 2024年 251卷

作者： Tsirogiannis, Evangelos Ch. Daskalakis, Evangelos Vogiatzis, Christos Psarommatis, Foivos Bartolo, Paulo EODH SA Res & Dev Dept Lakkoma GR-63080 Chalkidikis Greece Univ Manchester Sch Mech Aerosp & Civil Engn Manchester M13 9PL England Univ Oslo Dept Informat SIRIUS Gaustadalleen 23B N-0373 Oslo Norway Nanyang Technol Univ Singapore Ctr 3D Printing Sch Mech & Aerosp Engn Singapore City 639798 Singapore Aristotle Univ Thessaloniki Sch Mech Engn Lab Machine Elements & Machine Design GR-54124 Thessaloniki Greece Balkan Ctr Ctr Interdisciplinary Res & Innovat Digital Representat & Addit Mfg DRAM Bldg B10th km Thessaloniki-Thermi Rd Thessaloniki 57001 Greece

This study presents a new methodology for designing, manufacturing, and testing advanced armor protection systems and applied to the development of three different protection solutions suitable for real armored vehicles. The backplate laminates of the presented composite armor protection solutions were composed of three different materials: steel, aluminum AA6082, and aluminum alloy AA2024 reinforced by multi-walled carbon nanotubes (MWCNTs). The frontal laminates remained the same for the three cases. Keeping almost the same mass while changing the material of each backplate and adapting the thickness, the three different protection systems were ballistically tested and compared according to Level 4 (Level IV) of the standard AEP-STANAG 4569 (projectile 14.5 mm x 114 mm API B32) with real military tests. Furthermore, the performance of the total laminated structure and the performance of each backplate in the total laminated structure were compared in terms of deformation and ballistic fractures. High-quality images acquired by the high-speed camera were helpful in evaluating and comparing the backplates and the entire protection system. The results show that all three protection configurations present high performance mechanical properties and ballistic characteristics compared to commonly used armor systems. Even the under-developed AA2024-CNTs composite is a promising near-term backplate solution.

关键词： Passive armor protection Protective armor Ballistic performance Hybrid composites Vehicle protection

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Effects of surface wettability and thermal conductivity on the wear performance of ultrahigh molecular weight polyethylene/graphite and ultrahigh molecular weight polyethylene/graphene oxide composites

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POLYMERS FOR ADVANCED TECHNOLOGIES 2022年第6期33卷 1916-1932页

作者： Shahemi, Nur Hidayah Liza, Shahira Sawae, Yoshinori Morita, Takehiro Shinmori, Hironori Yaakob, Yazid Univ Teknol Malaysia Malaysia Japan Int Inst Technol Dept Mech Precis Engn TriPreM I Kohza Kuala Lumpur 54100 Malaysia Kyushu Univ Fac Engn Dept Mech Engn Machine Elements & Design Engn Lab Fukuoka Fukuoka Japan Univ Putra Malaysia Fac Sci Dept Phys Serdang Malaysia

Recent studies have found a rapid increase of ultrahigh molecular weight polyethylene (UHMWPE) wear in the presence of proteins from the synovial fluid. Due to UHMWPE's high hydrophobicity, it tends to adsorb a tremendous amount of proteins. Moreover, since UHMWPE has low thermal conductivity, a temperature rise in the center of the contact area due to frictional heating could cause protein denaturation from the synovial fluid. It has been shown that the denatured protein may increase the adhesive wear response. This study aimed to address the effects of graphite and graphene oxide (GO) addition on the wear properties of UHMWPE in protein environments. The surface properties were characterized using surface roughness profiler, surface energy evaluation, zeta potential, and Fourier transform infra-red (FTIR). Following that, wear properties of UHMWPE composite were evaluated using a multidirectional pin-on-disc wear test under a bovine serum lubricated condition. The worn surface of the UHMWPE composite sample was evaluated, and the dominating factors of wear properties were determined. The effect of protein adsorption on the composite surface was also assessed after the wear test. The hydrophilicity of UHWMPE/1.0GO is considered to be the dominant contribution determining protein adsorption in static conditions. UHMWPE composite's wear resistance improvement was primarily dominated by GO filler (1.0 wt%) near the sliding surface, which has improved the subsurface strength of the material and heat dissipation effect, which reduces the denaturation of the proteins.

关键词： hydrophobicity protein adsorption surface charge surface free energy thermal conductivity UHMWPE

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Binder jetting of spinel-based refractory materials - processing, microstructure and properties

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ADDITIVE MANUFACTURING 2025年 102卷

作者： Freitag, Lisa Storti, Enrico Bretschneider, Leif Zeidler, Henning Hubalkova, Jana Aneziris, Christos G. TU Bergakad Freiberg Inst Ceram Refractories & Composite Mat Agr Str 17 D-09599 Freiberg Germany Tampere Univ TAU Fac Engn & Nat Sci Mat Sci & Environm Engn Korkeakoulunkatu 6POB 589 Tampere 33014 Finland Empa Swiss Fed Labs Mat Sci & Technol Lab High Performance Ceram Uberlandstr 129 CH-8600 Dubendorf Switzerland TU Bergakad Freiberg Inst Machine Elements Design & Mfg Chair Addit Mfg Agr Str 1 D-09599 Freiberg Germany

Spinel-based refractories were produced by binder jetting using a novel MgO-citric acid binder system and water as an activator of the acid-base reaction. Additionally to different amounts of binder and saturation levels, the addition of small amounts of PVA was investigated. Powder characteristics such as particle size distribution, particle shape and flowability as well as thermal behavior of the binder system were evaluated. Phase analysis by XRD conducted on dried and sintered samples indicated in situ spinel formation. Sintered samples exhibited low shrinkage (< 4%), but rather high apparent porosity (>50 vol.%) and median pore size (>25 mu m). Compressive strength of dried and sintered samples was measured both parallel and perpendicular to the printed layers with values up to 8.5 MPa in the sintered state. After thermal shock with water, microcracks were formed and the residual strength was about 1.9 MPa. Selected sintered samples were analyzed with microfocused X-ray computed tomography, revealing the orientation of larger angular-shaped particles along the printed layers. Finally, a small crucible was successfully printed and sintered.

关键词： Refractories Additive manufacturing Binder jetting Spinel Microstructure

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A Review on Sensor-Integrating machine elements

ADVANCED SENSOR RESEARCH

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ADVANCED SENSOR RESEARCH 2024年第4期3卷

作者： Kirchner, Eckhard Wallmersperger, Thomas Gwosch, Thomas Menning, Johannes D. M. Peters, Julian Breimann, Richard Kraus, Benjamin Welzbacher, Peter Kuechenhof, Jan Krause, Dieter Knoll, Erich Otto, Michael Muhammedi, Benjamin Seltmann, Stephanie Hasse, Alexander Schaefer, Guenter Lohrengel, Armin Thielen, Stefan Stiemcke, Yvo Koch, Oliver Ewert, Arthur Rosenloecher, Thomas Schlecht, Berthold Prokopchuk, Artem Henke, Ernst-Friedrich Markus Herbst, Felix Matthiesen, Sven Riehl, David Keil, Ferdinand Hofmann, Klaus Pape, Florian Konopka, Dennis Poll, Gerhard Steppeler, Tobias Ottermann, Rico Dencker, Folke Wurz, Marc C. Puchtler, Steffen Baszenski, Thao Winnertz, Martin Jacobs, Georg Lehmann, Benjamin Stahl, Karsten Tech Univ Darmstadt Inst Prod Dev & Machine Elements D-64287 Darmstadt Germany Tech Univ Dresden Inst Solid Mech D-01069 Dresden Germany Karlsruhe Inst Technol KIT IPEK Inst Prod Engn D-76131 Karlsruhe Germany Swiss Fed Inst Technol Dept Mech & Proc Engn Prod Dev Grp Zurich CH-8092 Zurich Switzerland Hamburg Univ Technol Inst Prod Dev & Mech Engn Design D-21073 Hamburg Germany TUM Sch Engn & Design Inst Machine Elements TUM Sch Engn & Design D-85748 Garching Germany Tech Univ Chemnitz Inst Design Engn & Drive Technol IKAT D-09107 Chemnitz Germany Tech Univ Clausthal Inst Mech Engn D-38678 Clausthal Zellerfeld Germany RPTU Kaiserslautern Chair Machine Elements Gears & Tribol D-67663 Kaiserslautern Germany Tech Univ Dresden Inst Machine Elements & Machine Design D-01069 Dresden Germany Tech Univ Dresden Inst Semicond & Microsyst D-01069 Dresden Germany Tech Univ Darmstadt Integrated Elect Syst Lab D-64283 Darmstadt Germany Tech Univ Darmstadt Measurement & Sensor Technol Grp D-64289 Darmstadt Germany Leibniz Univ Hannover Inst Machine Design & Tribol IMKT D-30823 Hannover Germany Leibniz Univ Hannover Inst Micro Prod Technol IMPT D-30823 Hannover Germany Rhein Westfal TH Aachen Inst Machine Elements & Syst Engn D-52062 Aachen Germany

This contribution summarizes the current state of research regarding so-called sensor-integrating machine elements as an enabler of digitalization in mechanical engineering and--if available-their application in industry. The focus is on the methodical aspects of the development of these machine elements in general as well as specific sensor-integrating machine elements that are either already in use or currently under development. Developmental aspects include the robust design of initially evaluated concepts for sensor-integrating machine elements as well as their modularization. Smart materials with sensory functions are included in the analysis as well as the differentiation with regard to add-on sensors. The aim of the authors interlinked by a special research program funded by the German Research Foundation (DFG) is to facilitate the exchange with other researchers with the help of the comprehensive overview given in this contribution. The contribution concludes with a brief discussion of open challenges, such as the energy supply and data transfer in rotating systems and also data security. This contribution summarizes the current state of research regarding sensor-integrating machine elements as an enabler of digitalization in mechanical engineering. The focus is on the methodical aspects of the development of these machine elements in general as well as specific sensor-integrating machine elements that are either already in use or currently under development. image

关键词： development methods machine elements mechatronic systems modularization sensors

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A FEM-Based 2D Model for Simulation and Qualitative Assessment of Shot-Peening Processes

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MATERIALS 2021年第11期14卷 2784页

作者： Maliaris, Georgios Gakias, Christos Malikoutsakis, Michail Savaidis, Georgios Int Hellen Univ Sch Sci Dept Chem Kavala 65404 Greece Aristotle Univ Thessaloniki Sch Mech Engn Lab Machine Elements & Machine Design Thessaloniki 54124 Greece

Shot peening is one of the most favored surface treatment processes mostly applied on large-scale engineering components to enhance their fatigue performance. Due to the stochastic nature and the mutual interactions of process parameters and the partially contradictory effects caused on the component's surface (increase in residual stress, work-hardening, and increase in roughness), there is demand for capable and user-friendly simulation models to support the responsible engineers in developing optimal shot-peening processes. The present paper contains a user-friendly Finite Element Method-based 2D model covering all major process parameters. Its novelty and scientific breakthrough lie in its capability to consider various size distributions and elastoplastic material properties of the shots. Therewith, the model is capable to provide insight into the influence of every individual process parameter and their interactions. Despite certain restrictions arising from its 2D nature, the model can be accurately applied for qualitative or comparative studies and processes' assessments to select the most promising one(s) for the further experimental investigations. The model is applied to a high-strength steel grade used for automotive leaf springs considering real shot size distributions. The results reveal that the increase in shot velocity and the impact angle increase the extent of the residual stresses but also the surface roughness. The usage of elastoplastic material properties for the shots has been proved crucial to obtain physically reasonable results regarding the component's behavior.

关键词： shot peening finite element method modeling simulation shot dynamics residual stresses surface roughness

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The relations between wear behavior and basic material properties of graphene-based materials reinforced ultrahigh molecular weight polyethylene

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POLYMERS FOR ADVANCED TECHNOLOGIES 2021年第11期32卷 4263-4281页

作者： Shahemi, Nur Hidayah Liza, Shahira Sawae, Yoshinori Morita, Takehiro Fukuda, Kanao Yaakob, Yazid Univ Teknol Malaysia Malaysia Japan Int Inst Technol Dept Mech Precis Engn TriPreM i Kohza Kuala Lumpur 54100 Malaysia Kyushu Univ Dept Mech Engn Machine Elements & Design Engn Lab Fac Engn Fukuoka Japan Univ Putra Malaysia Dept Phys Fac Sci Serdang Malaysia

This article aims to investigate the influence of reinforcing graphene oxide (GO) and graphite flakes (GF) fillers into ultrahigh molecular weight polyethylene (UHMWPE) for orthopedic application. These fillers were expected to physically bond to UHMWPE, thus can enhance the subsurface strength, improving the wear behavior of the composites. UHMWPE/GO and UHMWPE/GF composites were prepared at 0.1 and 1.0 wt% by melt-blending, followed by a compression molding technique. A multidirectional pin-on-disc wear test was performed to simulate the kinematic of hip application. Whilst getting exposed in the artificial in-vivo lubricant bath (30 v/v% diluted bovine serum). Following this, the wear mechanism fostered by each filler (GO and GF) was determined by wear features obtained from the optical microscope and scanning electron microscope (SEM). The crystallinity degree and crystal defect were assessed using x-ray diffraction (XRD). The mechanical properties of fabricated composites were evaluated by using a universal testing machine and Vickers microhardness. We found that UHMWPE/GO has the lowest specific wear rate due to the improved subsurface strength, as the reduction of a weak adhesive point was observed on the worn surface. Meanwhile, higher GF content (1 wt%) in UHMWPE displayed a lower specific wear rate than neat UHMWPE after completing the 10 km sliding distance attributed to the filler resurfaced, responsible for providing a strong resistance of the shear stress applied upon sliding with the metal counterface. Interestingly, the hardness and tensile strength for both UHMWPE/GO and UHMWPE/GF increased, although the crystallinity percentage was declining compared to neat UHMWPE.

关键词： adhesive wear graphene oxide graphite physical bonding UHMWPE wear mechanism

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Stress-Shot-Peened Leaf Springs Material Analysis through Nano- and Micro-Indentations

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MATERIALS 2021年第17期14卷 4795-4795页

作者： Pappa, Maria Savaidis, Georgios Michailidis, Nikolaos Aristotle Univ Thessaloniki Sch Mech Engn Phys Met Lab GR-54124 Thessaloniki Greece Aristotle Univ Thessaloniki Sch Mech Engn Lab Machine Elements & Machine Design GR-54124 Thessaloniki Greece

Heat-treated and shot-peened lightweight steels with demanding requirements for durability are applied in high-performance automotive leaf springs. Due to their heat-treatment they exhibit degraded properties in the surface-near area compared to the core. This area, which may extend until 300 mu m from the surface to the core, experiences the highest bending stresses at operation. The microstructure in the surface and sub-surface layers determines the mechanical performance as well as the wear resistance. The present study refers to the material properties of a stress shot-peened 51CrV4 steel at various depths from the surface. The effect of the manufacturing process has been captured both by Vickers micro-hardness measurements and nanoindentation. The latter combined with a Fine Element Method (FEM)-based algorithm enables the determination of variations in the material's stress-strain curves over the affected layers, which translate to internal stress changes. The nanoindentation technique has been applied here successfully for the first time ever on leaf springs. The combination of microstructural analysis, microhardness and nanoindentation captures the changes of the treated material, offering insights on the material characteristics, and yielding accurate elastoplastic material properties for local, layered-based analysis of the components' mechanical performance at operational loading scenarios, i.e., in the framework of stress shot-peening simulation models.

关键词： nanoindentation microstructural analysis mechanical properties shot peening

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A nonlinear African vulture optimization algorithm combining Henon chaotic mapping theory and reverse learning competition strategy

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EXPERT SYSTEMS WITH APPLICATIONS 2024年 236卷

作者： Wang, Baiyi Zhang, Zipeng Siarry, Patrick Liu, Xinhua Krolczyk, Grzegorz Hua, Dezheng Brumercik, Frantisek Li, Z. China Univ Min & Technol Sch Mechatron Engn Xuzhou Peoples R China Univ Paris Est Creteil Val de Marne 61 Ave Gen Gaulle F-94010 Creteil France Univ Zilina Fac Mech Engn Dept Design & Machine Elements Univ 1 Zilina 01026 Slovakia Donghai Lab Zhoushan 316021 Zhejiang Peoples R China Opole Univ Technol Dept Mfg Engn & Automat Prod PL-45758 Opole Poland

As a new intelligent optimization algorithm, the African vultures optimization algorithm (AVOA) has been widely used in various fields today. However, when solving complex multimodal problems, the AVOA still has some shortcomings, such as low searching accuracy, deficiency on the search capability and tendency to fall into local optimum. In order to alleviate the main shortcomings of the AVOA, a nonlinear African vulture optimization algorithm combining Henon chaotic mapping theory and reverse learning competition strategy (HWEAVOA) is proposed. Firstly, the Henon chaotic mapping theory and elite population strategy are proposed to improve the randomness and diversity of the vulture's initial population;Furthermore, the nonlinear adaptive incremental inertial weight factor is introduced in the location update phase to rationally balance the exploration and exploitation abilities, and avoid individual falling into a local optimum;The reverse learning competition strategy is designed to expand the discovery fields for the optimal solution and strengthen the ability to jump out of the local optimal solution. HWEAVOA and other advanced comparison algorithms are used to solve classical and CEC2022 test functions. Compared with other algorithms, the convergence curves of the HWEAVOA drop faster and the line bodies are smoother. These experimental results show the proposed HWEAVOA is ranked first in all test functions, which is superior to the comparison algorithms in convergence speed, optimization ability, and solution stability. Meanwhile, HWEAVOA has reached the general level in the algorithm complexity, and its overall performance is competitive in the swarm intelligence algorithms.

关键词： African vultures optimization algorithm Henon chaotic mapping theory Nonlinear adaptive incremental inertial weight factor Reverse learning competition strategy

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Current Challenges in the design of Drives for Robot-Like Systems

Current Challenges in the Design of Drives for Robot-Like Sy...

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IEEE International Conference on Systems, Man, and Cybernetics (SMC)

作者： Vogel-Heuser, Birgit Zimmermann, Markus Stahl, Karsten Land, Kathrin Ocker, Felix Roetzer, Sebastian Landler, Stefan Otto, Michael Tech Univ Munich Inst Automat & Informat Syst Garching Germany Tech Univ Munich Lab Prod Dev & Lightweight Design Garching Germany Tech Univ Munich Inst Machine Elements Garching Germany

ISBN: (纸本)9781728185262

Companies producing Robot-Like Systems (RLS) must increase efficiency in design and production in order to stay competitive in the international market. Such RLS range from small SCARA robots to entire production facilities. Very different systems for similar tasks are published in research or offered in the market. A clear path to an optimal configuration for a given task is apparently not available to the engineer. This indicates that the gear drives of such RLS and their integration with automation technology are still insufficiently researched, and their efficient design poses significant challenges for the industry. This paper identifies and provides a concise overview of requirements and challenges in the context of drives for such RLS. Building on this overview, suggestions are made for the future course of action in research.

关键词： robot-like systems drive systems challenges

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A Numerical Model for Solving Three-Dimensional Rolling Contact Problems with Elastic Coating Layers

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TRIBOLOGY LETTERS 2021年第4期69卷 139-139页

作者： Xi, Yinhu Bjorling, Marcus Almqvist, Andreas Xi An Jiao Tong Univ Theory Lubricat & Bearing Inst Key Lab Educ Minist Modern Design & Rotor Bearing Xian 710049 Peoples R China Lulea Univ Technol Dept Engn Sci & Math Div Machine Elements S-97187 Lulea Sweden

In this work, a numerical model is proposed for three-dimensional rolling contact problems with one or two elastic layers, and the tangential contact solution is emphasized. Previous works on this topic have mostly been two-dimensional, in which only longitudinal creepage has been considered. With the three-dimensional model presented in this work, all possible creepages, such as the longitudinal, lateral and spin creepages are taken into account. In order to improve the calculation efficiency, the conjugate gradient method and the FFT technique are employed. The influence coefficients for displacement and stress are obtained from the corresponding frequency response functions. The numerical results are validated against existing results and good agreement can be found. The effects of the different layers' thicknesses and elastic moduli under different creepage combinations on the traction distribution and stick/slip results are investigated. It can be seen that by adjusting the layer parameters the traction and stick/slip results can be modified significantly, and it may, therefore, be very useful information for improving the rolling contact fatigue and mitigating wear problems in various mechanical systems.

关键词： Rolling contact problems Layer Lateral creepage Spin creepage Stick and slip

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