Article
Engineering, Marine
Alireza Pakrooyan, Peyman Yousefi, Korosh Khorshidi, Mohammad Mahdi Najafizadeh, Alireza Nezamabadi
Summary: This paper presents a parametric investigation on the free vibration characteristics of an auxetic honeycomb sandwich plate mounted at the wall of a liquid tank. The study adopts different models to describe the physical properties of the core and face sheets, and derives the governing equations of motion using mathematical methods. The results indicate that the thickness of the face sheet, the cell wall, and the cell aspect ratio are the main factors affecting the wet fundamental frequency.
Article
Mechanics
Suian Wang, Chuang Deng, Olanrewaju Ojo, Bamidele Akinrinlola, Jared Kozub, Nan Wu
Summary: The newly proposed honeycomb meta-material with specific auxetic reentrant design shows excellent energy absorption capacity, distinct hardening process, and good lateral shrinkage behavior under compression. It becomes a solid material with low porosity and high stiffness after full compression to provide further protection or support for its neighbor objectives.
COMPOSITE STRUCTURES
(2022)
Article
Chemistry, Multidisciplinary
Dimitrios Chinis, Georgios E. Stavroulakis
Summary: This study utilizes finite element numerical models to discover and analyze the band gaps that occur in a material with cookie-shaped auxetic microstructures. The advantage of these microstructures lies in their production and fatigue resistance.
APPLIED SCIENCES-BASEL
(2023)
Article
Mechanics
Faezeh Shalchy, Jenny Carlsson, Vikram Deshpande, Norman Fleck
Summary: The effect of gel-filling on the transverse compressive response of a hexagonal honeycomb is investigated. It is found that gel-filling changes the deformation mode and increases the pinch load due to the presence of incompressible gel-core and membrane tension within the honeycomb walls.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Engineering, Mechanical
Mohammad Hossein Zamani, Mohammad Heidari-Rarani, Keivan Torabi
Summary: A novel angle graded auxetic honeycomb (AGAH) core with varying cell angles and constant wall thickness along the gradation has been designed. New analytical relations were proposed to predict the equivalent elastic properties of the core, which enhances specific stiffness and natural frequencies of sandwich structures. Analytical and finite element analyses were conducted to assess the core performance and investigate its impact on the vibration response of sandwich panels.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2022)
Article
Engineering, Multidisciplinary
Markus Mehnert, William Oates, Paul Steinmann
Summary: When molecular photo-switches are embedded into a soft polymer matrix, they can undergo mechanical deformation induced by specific wavelength light. These photo-sensitive compounds have potential applications as soft actuators, especially in micro-scale robots and high-speed data transfer. However, the industrial applications of photo-sensitive polymers have been limited. This study presents a photo-mechanical modeling approach using constitutive equations and numerical simulation methods to increase the acceptance of these materials.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Engineering, Civil
Hoang-Anh Pham, Huu-Quoc Tran, Minh-Tu Tran, Van-Loi Nguyen, Quy-Truong Huong
Summary: This study presents an analytical approach for the free vibration analysis of doubly curved stiffened sandwich shells with functionally graded face sheets and an auxetic honeycomb core layer. The methodology can be used to examine various shell types and an optimization technique is introduced to maximize the natural frequency.
THIN-WALLED STRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
Gideon A. Lyngdoh, Nora-Kristin Kelter, Sami Doner, N. M. Anoop Krishnan, Sumanta Das
Summary: This paper integrates finite element analysis and machine learning to predict the Poisson's ratios of auxetic cellular cementitious composites. By generating a dataset with different void features combinations, a neural network approach shows excellent prediction efficacy.
MATERIALS & DESIGN
(2022)
Article
Engineering, Civil
Hoang-Anh Pham, Huu-Quoc Tran, Minh-Tu Tran, Van-Loi Nguyen, Quy-Truong Huong
Summary: This study introduces an analytical approach for the free vibration analysis of doubly curved stiffened sandwich shells with functionally graded face sheets and an auxetic honeycomb core layer. Numerical results show that the fundamental frequency is significantly influenced by the constituent materials of the face layers, the geometrical parameters of the auxetic honeycomb core layer, and the stiffeners. A simple optimization technique based on Rao algorithms is proposed to maximize the natural frequency of the shell by adjusting parameters such as the thickness of the core and the number of stiffeners.
THIN-WALLED STRUCTURES
(2022)
Article
Engineering, Mechanical
Ganchao Chen, Yuansheng Cheng, Pan Zhang, Jun Liu, Changhai Chen, Sipei Cai
Summary: The study introduced a metallic auxetic double arrowhead honeycomb core sandwich panel and investigated its deformation response and energy dissipation characteristics under air blasts. Results indicated that the deformation response of the panel was closely related to their deformation/failure mechanisms. Changing the core web thickness and inclined angles significantly influenced the panel deformation response. Increasing the number of core layers led to a more remarkable decrease in permanent deflections.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Pengju Li, Xilin Zhang, Zhengkai Zhang, Qingguo Wen
Summary: A new force measurement method based on the auxetic structure is proposed in this paper, using a light source, auxetic structure, and solar cell. The method avoids contact between components, and experimental results show improved sensitivity and linearity over traditional methods.
IEEE SENSORS JOURNAL
(2021)
Article
Materials Science, Multidisciplinary
Reza Jafari Nedoushan, Yongsan An, Woong-Ryeol Yu
Summary: Cellular auxetic materials, a type of metamaterial, have attracted much interest due to their promising mechanical properties. However, their low stiffness and strength, caused by a bending-dominant structure, are major shortcomings. This study presents a novel design concept to address this issue and demonstrates the tunability and extensive range of these structures.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Review
Engineering, Multidisciplinary
Wei Jiang, Xin Ren, Shi Long Wang, Xue Gang Zhang, Xing Yu Zhang, Chen Luo, Yi Min Xie, Fabrizio Scarpa, Andrew Alderson, Ken E. Evans
Summary: Auxetic foams exhibit unique mechanical properties and multiphysics characteristics, making them potential candidates for applications in biomedicine, aerospace, and smart sensing. However, challenges such as complex fabrication and lacking stability hinder their practical applications, requiring further research and development to overcome these barriers.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Engineering, Civil
Quoc-Hoa Pham, Phu-Cuong Nguyen, Trung Thanh Tran
Summary: This article presents the combination of mixed interpolation of tensorial components technique of triangular elements and the edge-based smoothed finite element method (ES-MITC3) developed on the higher-order shear deformation theory (HSDT). The free vibration behavior of auxetic honeycomb sandwich plates with the functionally graded material (FGM) skin layers is trained and predicted by an artificial neural network (ANN) model using Matlab coding. The effects of parameters such as geometrical and material properties on the free vibration behavior of auxetic honeycomb sandwich plates with FGM skin layers are investigated in detail.
THIN-WALLED STRUCTURES
(2022)
Article
Mechanics
Nam V. Nguyen, H. Nguyen-Xuan, Tan N. Nguyen, Joowon Kang, Jaehong Lee
Summary: This study proposes a computational approach for examining the behaviors of auxetic honeycomb sandwich plate structures, utilizing a combination of polygonal meshes and advanced deformation theory. By incorporating negative Poisson's ratio auxetic honeycomb cells and graphene nanoplatelets reinforcement, the sandwich plate structures achieve ultra-light features and enhanced stiffness. Bolotin's approach is utilized to determine the dynamic instability region of the sandwich plate structures.
COMPOSITE STRUCTURES
(2021)
Review
Materials Science, Multidisciplinary
James N. Grima-Cornish, Daphne Attard, Joseph N. Grima, Kenneth E. Evans
Summary: The article explores how ancient symmetrical esthetic artifacts have been transformed into functional auxetics through mechanisms in the field of mechanical metamaterials and architected materials. It focuses on the important role and various implementations of rotating rigid units at different scales of structure.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Pierre-Sandre Farrugia, Ruben Gatt, Luke Mizzi, Joseph N. Grima
Summary: The deformation behavior of intersecting ligaments forming variants of the square and rectangular grids under mechanical compression was investigated. It was shown that these systems can exhibit a negative incremental Poisson's ratio at relatively large axial compressive strains. The extent of auxeticity depends on the relative offset of successive ligaments, the relative lengths of the ligaments as well as on their thickness. Two distinct modes of deformation were observed, one resembling that of the reentrant hexagonal honeycomb and the other that of the meta-tetrachiral system.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Chemistry, Physical
Jakub W. Narojczyk, Mikolaj Bilski, Joseph N. Grima, Przemyslaw Kedziora, Dmitrij Morozow, Miroslaw Rucki, Krzysztof W. Wojciechowski
Summary: Negative Poisson's ratio materials challenge our traditional understanding of elastic properties and offer a wide range of potential applications. Modifying the structure of existing materials allows us to control elastic properties and anisotropy in cubic systems.
Article
Mechanics
Luke Mizzi, Andrea Spaggiari
Summary: This study investigates the impact of introducing geometric chiral characteristics on the mechanical properties of Euclidean polygonal tessellations with octahedral or dodecahedral elements. The research discovers three novel auxetic metamaterials with potentially large negative Poisson's ratios and high in-plane isotropy. It further demonstrates the control of auxeticity through tuning the geometric parameters. This work highlights the potential of Euclidean polygonal tessellations in designing innovative auxetic metamaterials and provides insights into the deformation mechanisms and geometric conditions that lead to this anomalous property.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Physics, Condensed Matter
James N. Grima-Cornish, Daphne Attard, Liana Vella-Zarb, Joseph N. Grima, Kenneth E. Evans
Summary: Inspired by single crystal boron arsenate, novel mechanical metamaterials are built at the macroscale using conventional materials and investigated through finite element simulations. These metamaterials can mimic the properties of boron arsenate, with the rotating rigid-units mechanism being excellently replicated and even made more efficient through modifications of the geometry. The study confirms that existing materials can provide useful information for designing novel mechanical metamaterials with enhanced auxetic properties.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
James N. N. Grima-Cornish, Liana Vella-Zarb, Joseph N. N. Grima, Kenneth E. E. Evans
Summary: The mechanical properties of single crystals boron arsenate, BAsO4, are simulated under various pressures using density functional theory. The results show that the elastic constants and auxeticity are highly dependent on pressure, with maximum auxetic behavior observed at around 15 GPa.
Article
Physics, Condensed Matter
Russell Galea, Pierre-Sandre Farrugia, Krzysztof K. Dudek, Louis Zammit Mangion, Joseph N. Grima, Ruben Gatt
Summary: This study investigates an accordion-like system with embedded magnetic inclusion and demonstrates that its deformation depends on the magnetic moment and length of the embedded magnets. The stacking of the accordion-like system forms hexagonal honeycombs with varying Poisson's ratio, which can be altered by the positioning and properties of the magnetic inclusion and magnetic field. The dimensions of these structures can be controlled through external magnetic fields, allowing for high turnability and real-time behavior modification.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2022)
Article
Instruments & Instrumentation
Konstantin Tretiakov, Pawel M. Piglowski, Krzysztof W. Wojciechowski
Summary: Research on auxetic materials is gaining attention for their various applications in enhancing mechanical properties. This study investigates the effect of nanoinclusions in auxetic metamaterials, specifically the Yukawa crystals with nanochannels. The results show that the presence of nanochannels can significantly affect the auxetic behavior of the crystals, and the properties are influenced by the type of nanochannels and pressure.
SMART MATERIALS AND STRUCTURES
(2023)
Article
Instruments & Instrumentation
Luke Mizzi, Seyedeh Farzaneh Hoseini, Marco Formighieri, Andrea Spaggiari
Summary: Shape memory alloys (SMA) are used in a novel SMA-metamaterial actuator to achieve a reversible, global elongation in multiple directions. The actuator consists of an SMA component, a bias component, and a metamaterial geometry that amplify and re-direct the unidirectional SMA actuation. A prototype actuator was tested in different configurations to demonstrate its functionality and reusability. A theoretical model was developed to predict the actuation stroke based on material properties and geometry, and was validated.
SMART MATERIALS AND STRUCTURES
(2023)
Article
Mechanics
K. K. Dudek, L. Mizzi, J. A. Iglesias Martinez, A. Spaggiari, G. Ulliac, R. Gatt, J. N. Grima, V. Laude, M. Kadic
Summary: The ability to control Poisson's ratio of functional materials is essential for the development of efficient structures in various fields. This study proposes novel microscopic 2D and 3D functionally-graded mechanical metamaterials that can exhibit a wide range of Poisson's ratio depending on their composition. The research also explores the dynamic properties of these structures, specifically how the variation in composition affects wave propagation velocity. This has significant implications for applications involving wave attenuation or sensors.
COMPOSITE STRUCTURES
(2023)
Article
Biotechnology & Applied Microbiology
Tonio P. Agius, Dario Cerasola, Michael Gauci, Anabel Sciriha, Darren Sillato, Cynthia Formosa, Alfred Gatt, John Xerri de Caro, Robert Needham, Nachiappan Chockalingam, Joseph N. Grima
Summary: This study analyzes the specific kinematics of fixed-seat rowing and compares it with sliding-seat rowing. The results show that fixed-seat rowing involves more forward and backward movement of the thorax, but less spinal movement compared to sliding-seat rowing. This biomechanical explanation helps to understand why fixed-seat rowers do not have an increased risk of back injuries compared to sliding-seat rowers.
BIOENGINEERING-BASEL
(2023)
Article
Engineering, Multidisciplinary
Daphne Attard, Roberto Caruana-Gauci, Dario Cerasola, James N. Grima-Cornish, Daniel S. Bezzina, Giovanni Ficarra, Joseph N. Grima
Summary: Finite element simulations were carried out to examine the effect of shearing on finite-sized auxetic and non-auxetic samples. It was found that auxetics exhibited distinct characteristics compared to non-auxetic materials when subjected to shear testing, including extensive lateral expansion and the formation of significant concave creases on exposed lateral faces. The presence of these creases became more pronounced under combined shear and compressive loads, highlighting the need to consider their influence when evaluating the suitability of auxetics for practical applications involving shear loading.
ENGINEERING RESEARCH EXPRESS
(2023)
Article
Medicine, General & Internal
Joseph N. Grima, Michelle Vella Wood, Nadia Portelli, James N. Grima-Cornish, Daphne Attard, Alfred Gatt, Cynthia Formosa, Dario Cerasola
Summary: This study investigated the prevalence of dermatological issues (calluses and blisters) on rowers' hands, as well as their perceptions and pain tolerance. The results showed that most rowers considered calluses to be non-painful, while blisters were perceived as more painful. Blisters and calluses were mainly located on the lower parts of the fingers and the upper inner palms.
MEDICINA-LITHUANIA
(2022)
Article
Engineering, Multidisciplinary
Keyu Zhu, Xitao Zheng, Jing Peng, Jiaming Sun, Ruilin Huang, Leilei Yan
Summary: This paper discusses the influence of multiple impacts on the compression strength of honeycomb sandwich structures with composite face sheets. It is found that the size of the impactor affects the turning point of the compression strength. Additionally, high impact energy leads to damage in the bottom face sheet and reduces the overall compression strength.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Danqian Wang, Yanfei Yue, Jueshi Qian
Summary: Magnesium Potassium Phosphate Cement (MKPC) as a binder for steel rebars shows improved corrosion resistance when subjected to carbonation, due to the increase in pH and the formation of a more protective oxide film.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Zhibin Li, Wenyu Wang, Pengcheng Xue, Xingyu Wei, Jian Xiong
Summary: This work proposes a design approach and manufacturing method for carbon fiber reinforced plastic (CFRP) corrugated sandwich truncated cones (CSTC) to improve their anti-debonding ability and ensure reliability. The study establishes theoretical models for CSTCs' stiffness and failure modes, which are verified through experiments and finite element analysis (FEA). The research reveals the effect of geometric parameters on failure modes and performs an optimal design for CSTC structures. The findings have significant implications for the design and application of lightweight CSTCs in constructions, such as launch vehicle adapters.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Mingyu Zhang, Lei Chu, Jiahua Chen, Fuxun Qi, Xiaoyan Li, Xinliang Chen, Deng-Guang Yu
Summary: This review summarizes the different structures and construction methods of fibrous membranes with asymmetric wettability. It also reviews the biological applications of these membranes and suggests future challenges.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
E. Mofakhami, L. Gervat, B. Fayolle, G. Miquelard-Garnier, C. Ovalle, L. Laiarinandrasana
Summary: This study investigates the effects of fibre concentration on the mechanical response of welded glass-fibre-reinforced polypropylene (GF-PP). Experimental observations reveal a significant reduction in weld ratio, up to 60%, indicating a decreased strength compared to the bulk material. Increasing fibre content in the welded material results in a decrease in stress at break and strain at the maximum stress. The use of DIC technique and X-ray microtomography further confirms the localized strain amplification in the welded zone due to the significant increase in fibre density.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Emad Pourahmadi, Farjad Shadmehri, Rajamohan Ganesan
Summary: This research compares the mechanical properties of laminates manufactured using automated fiber placement and conventional autoclave curing methods. The results show that laminates manufactured using automated fiber placement have a lower interlaminar shear strength compared to laminates reconsolidated using autoclave curing. A finite element simulation method is proposed to quantitatively analyze these differences.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Johnny Jakobsen, Benny Endelt, Fahimeh Shakibapour
Summary: This study proposes a new bolted/pinned joining method for composite applications, which improves load transfer by introducing a patch-type reinforcement. Experimental results demonstrate significant improvements in both static and fatigue load conditions compared to existing methods. Finite element simulations highlight the advantage of this method, as it creates a more efficient load-transferring mechanism through different stress distributions.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Gisele G. Cintra, Janine D. Vieira, Daniel C. T. Cardoso, Thomas Keller
Summary: This paper proposes a novel approach to assess multi-crack behavior in layered fiber-polymer composites. The generated Compliance and R-curves provide useful insights into understanding the multiple delamination process and allow for separate evaluation of strain energy release rate (SERR) for each crack. The developed cohesive zone model successfully simulates the failure process zone of three parallel cracks, showing good agreement between the numerical model and experimental results.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Renil Thomas Kidangan, Sreedhar Unnikrishnakurup, C. Krishnamurthy, Krishnan Balasubramaniam
Summary: The induction heating process can accurately identify fiber orientation and stacking order, making it a valuable tool for large-area inspection and quality control in manufacturing fiber-reinforced composites.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Sungjun Hwang, Yousoo Han, Douglas J. Gardner
Summary: Bleached Kraft pulp, unbleached Kraft pulp, and old corrugated cardboard pulp are suitable for producing cellulose nanofibril suspensions. Spray drying is a fast, simple, cost-effective, and scalable drying method. Spray-dried cellulose nanofibrils can be used as reinforcing materials in polypropylene matrices. The particle size of cellulose nanofibrils affects the material properties.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Mehdi Mahdavi, Abbas Zolfaghari
Summary: This study aims to improve the recovery forces of shape memory polymers (SMPs) through material extrusion additive manufacturing. By using glass fiber (GF) as reinforcement and manufacturing multi-layer composite specimens, it was found that PLA with 6.62% GF exhibited the best recovery force, which was further optimized through annealing heat treatment.
COMPOSITES PART B-ENGINEERING
(2024)
Review
Engineering, Multidisciplinary
Xiang Ao, Antonio Vazquez-Lopez, Davide Mocerino, Carlos Gonzalez, De-Yi Wang
Summary: The vulnerability of natural fibers to heat and fire poses a significant challenge for their substitution of traditional fiber reinforcements in composite materials. Natural fiber/polymer composites (NFCs) are regarded as potential candidates for engineering applications due to their environmental friendliness and low-impact sourcing. Thus, appropriate approaches need to be implemented to enhance the fire safety of NFCs. This review summarizes and discusses the latest understanding of flammability and thermal properties of natural fibers, with a special focus on their interaction with polymer matrix in fire behavior. Additionally, the latest developments in flame-retardant approaches for NFCs are reviewed, covering both flame retardancy and fire structural integrity. Finally, future prospects and perspectives on fire safety of NFCs are proposed, providing insights into further advancements of NFCs.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Cheng Wang, Siqi Huo, Guofeng Ye, Bingtao Wang, Zhenghong Guo, Qi Zhang, Pingan Song, Hao Wang, Zhitian Liu
Summary: The demand for multifunctional, transparent epoxy resin with superior dielectric, mechanical, and fire-safety performances is increasing in modern industries. Researchers have developed an epoxidized, phosphaphenanthrene-containing poly(styrene butadiene styrene) (ESD) for advanced fire-safe epoxy resin, which maintains high transparency and improves UV-blocking property. The addition of 10 wt% ESD results in improved mechanical properties, decreased dielectric constant and loss, and outperformance compared to other fire-safe epoxy resins. This research provides an effective method for developing multifunctional flame-retardant epoxy resin.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Bo Pang, Heping Zheng, Zuquan Jin, Dongshuai Hou, Yunsheng Zhang, Xiaoyun Song, Yanan Sun, Zhiyong Liu, Wei She, Lin Yang, Mengyuan Li
Summary: This study develops an internal superhydrophobic material (ISM) using waste denitrification fly ash, which maintains stable hydrophobicity under harsh conditions of use and does not rely on expensive fluor-based surface modifications. The synthesized ISM has excellent matrix strength, strong waterproof properties, and retains superhydrophobicity even at damaged or friction interfaces.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Meirbek Mussatayev, Qiuji Yi, Mark Fitzgerald, Vincent K. Maes, Paul Wilcox, Robert Hughes
Summary: Real-time monitoring of carbon fibre composites during Automated Fibre Placement (AFP) manufacturing remains a challenge for non-destructive evaluation (NDE) techniques. This study designed a directional eddy-current (EC) probe to evaluate the detectability of out-of-plane wrinkles. Experimental evaluations and finite element modeling were conducted to better understand the relationship between eddy-current density and defect detection. The findings suggest that the probe configuration with an asymmetric driver coil and differential pickup coils shows the best capability for wrinkle detection.
COMPOSITES PART B-ENGINEERING
(2024)
