Fabrizio Scarpa | University of Bristol (original) (raw)

Papers by Fabrizio Scarpa

Research paper thumbnail of Auxetics and Other Unusual Systems - Preface

Physica Status Solidi B-basic Solid State Physics, 2009

Research paper thumbnail of Vibroacoustic optimization of anti-tetrachiral and auxetic hexagonal sandwich panels with gradient geometry

Smart Materials and Structures, Apr 5, 2016

The work describes the vibroacoustic behavior of anti-tetrachiral and auxetic hexagonal gradient ... more The work describes the vibroacoustic behavior of anti-tetrachiral and auxetic hexagonal gradient sandwich panels using homogenized finite element models to determine the mechanical properties of the auxetic structures, the natural frequencies and radiated sound power level of sandwich panels made by the auxetic cores. The mechanical properties and the vibroacoustic behavior of auxetic hexagonal sandwich panels are investigated as a benchmark. The radiated sound power level of the structure over the frequency range of 0 to 1000 Hz is minimized by modifying the core geometry of the gradient auxetic sandwich panels. Several excitation cases are considered. First-order and random optimization methods are used for the minimization of radiated sound power level of the structures. The results of this study present significant insights into the design of auxetic structures with respect to their vibroacoustical properties.

Research paper thumbnail of Investigation on Microstructure, Tensile Properties and Fatigue Characterization of Porous Date Palm Fiber

Journal of Natural Fibers, Oct 17, 2022

Research paper thumbnail of Open Shape Morphing Honeycombs Through Kirigami

This work presents an "open" and deployable honeycomb configuration created using kirigami-inspir... more This work presents an "open" and deployable honeycomb configuration created using kirigami-inspired cutting and folding techniques. The open honeycomb differs from traditional "closed" honeycomb by its reduced density and its increased flexibility. The exploitation of these characteristics for multifunctional applications is the focus of this work. Potential fields in which the open honeycomb could find application include sandwich panel manufacturing, morphing, and deployable structures.

Research paper thumbnail of A novel centresymmetric honeycomb composite structure

Composite Structures, Dec 1, 2005

In this paper analytical and finite element (FE) simulations are carried out to calculate the in-... more In this paper analytical and finite element (FE) simulations are carried out to calculate the in-plane PoissonÕs ratio and YoungÕs moduli of a new centresymmetric honeycomb configuration under uniaxial loading. Opposite to similar re-entrant honeycomb structures studied in the past, the new re-entrant unit cell topology takes into account possible manufacturing constraints typical of production routes like Resin Transfer Moulding (RTM) or Rapid Prototyping (RP). The results obtained through the analytical and FE analysis show a significant decrease of the PoissonÕs ratio for the internal cell angle between À20°and +20°compared to the classical re-entrant configurations exhibited in literature. The results also show that the presence of edge corners in the unit cell honeycomb configuration gives rise to a cellular structure with enhanced flexibility compared to the classical centresymmetric one. The results obtained by the analytical model show good agreement with the Gibson and Ashby rib-bending model when the honeycomb configuration reduces to the theoretical layout without modifications due to manufacturing constraints.

Research paper thumbnail of ICCST/7, Jan 20 -22

Research paper thumbnail of Investigation of the date palm fiber for green composites reinforcement: Quasi-static and fatigue characterization of the fiber

Industrial Crops and Products, Apr 1, 2020

This study focuses on the chemical and thermo-physical characterization of date palm fiber, which... more This study focuses on the chemical and thermo-physical characterization of date palm fiber, which can be used in the reinforcement of green composites. Alkaline solutions with different concentrations of NaOH (0.5, 1, 2 and 3%) and various immersion times (0.5, 1, 2, 4, 6 and 8h) at room temperature were used to treat fibers obtained from date palm fruit branches. In total, 750 samples were tested, and the results obtained show that the chemical treatment of the fibers can lead to an increase, up to 3 times, of their mechanical properties (strength and Young's modulus) in quasi-static tensile tests. Due to the dispersion in the experimental data, a statistical approach is required to evaluate the mechanical properties. To better understand the phenomena related to the physico-chemical properties of these fibers, several characterization techniques have been used, namely Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction. The data have been compared with results reported in the literature for other lignocellulosic fibers. 摘要 本文主要研究了椰枣纤维的化学和热物理性质，该纤维可用于增强绿色 复合材料，室温下不同浓度的氢氧化钠(0.5%、1%、2%、3%)和不同浸 泡时间(0.5%、1%、2、4、6、8h)的碱性溶液。采用E法处理枣果枝条 纤维.总共测试了750个样品，结果表明，在准静态拉伸试验中，纤维的化 学处理可使其力学性能(强度和杨氏模量)增加3倍.由于实验数据的分散 性，需要一种统计方法来评估力学性能.为了更好地理解与这些纤维物理 化学性质相关的现象，已经使用了几种表征技术，即傅立叶变换红外光 谱(FTIR)、热重分析(TGA)、差示扫描量热法(DSC)和X射线衍射。 这些数据与文献中其他木质纤维素纤维的结果进行了比较.

Research paper thumbnail of Transverse stiffness and strength of Kirigami zero-ν PEEK honeycombs

Composite Structures, Aug 1, 2014

This work describes the manufacture and characterisation of a PEEK-based zero Poisson's ratio hon... more This work describes the manufacture and characterisation of a PEEK-based zero Poisson's ratio honeycomb (SILICOMB) produced using Kirigami-inspired cutting and folding techniques. The flatwise compression and transverse shear properties of the structure are determined through ASTM mechanical testing, and the results compared against commercially available honeycombs, including several other zero Poisson's ratio cellular structures. An analytical model to predict the shear strength is compared to the results. SILICOMB specimens are found to have lower stiffness compared to other honeycomb configurations, but comparable strength. Factors influencing the results and variations to the manufacturing process are discussed.

Research paper thumbnail of Vibroacoustics of 2D gradient auxetic hexagonal honeycomb sandwich panels

Composite Structures, Mar 1, 2018

This paper describes the vibroacoustic behavior of sandwich panels with a novel core topology mad... more This paper describes the vibroacoustic behavior of sandwich panels with a novel core topology made from 2-dimensionally gradient auxetic hexagonal honeycombs. The 2D gradient core enables a tailoring of localized mechanical properties of the sandwich structure in different regions of the panel. A homogenized finite element modeling has been used to

Research paper thumbnail of Shape morphing Kirigami mechanical metamaterials

Scientific Reports, Aug 5, 2016

Research paper thumbnail of In-plane shear moduli of a new curved cell walls honeycomb plates for application in wings of wind turbines

This paper is focused on the identification of the in-plane shear moduli of a new design of auxet... more This paper is focused on the identification of the in-plane shear moduli of a new design of auxetic (negative Poisson's ratio) honeycomb configuration with curved cell walls by using analytical and numerical homogenization techniques. The sensitivity of the shear moduli is determined against the various cell geometry parameters. Good agreement between the analytical and numerical simulations is observed. We show that the specific curved wall honeycomb configuration applicated in plates witch build the structure of the wind turbines proposed in this paper possesses a high flexibly compared to the classical hexagonal cell, This leads to the needs of the wind turbine industry to minimize the weight of the wings and also to have a significant flexibility against the wind and the other external dynamic solicitations.

Research paper thumbnail of On the auxetic potential of 2D networks constructed from chiral building-blocks

Research paper thumbnail of CIMA 04 Boumerdes, Al, 30 November – 2 December

Research paper thumbnail of Characterization of a novel natural cellulosic fiber from Juncus effusus L

Carbohydrate Polymers, Sep 1, 2017

This study aims to assess the morphology and properties of fibers extracted from a wild natural p... more This study aims to assess the morphology and properties of fibers extracted from a wild natural plant largely available in Algeria known as Juncus effusus L. (JE). The morphology and diameter of the fiber bundles extracted from the stem of the JE plant were characterized by optical and scanning electron microscopy. The functional groups of the extracted lignocellulosic JE fibers were studied by FTIR, their thermal degradation behavior was investigated by TGA and their crystallinity was determined using X-ray diffraction technique. In addition, mechanical characterization was carried out using tensile tests on the lignocellulosic fiber in order to evaluate their strength, strain at break and Young's modulus. In view of the dispersion in the obtained experimental results, the latter were analyzed using the Weibull statistical laws with two and three parameters.

Research paper thumbnail of Manufacturing, characteristics and applications of auxetic foams: A state-of-the-art review

Composites Part B: Engineering, 2022

Auxetic foams counter-intuitively expand (shrink) under stretching (compression). These foams can... more Auxetic foams counter-intuitively expand (shrink) under stretching (compression). These foams can exhibit superior mechanical properties such as resistance to shear and indentation, improved toughness and energy absorption (EA) under several types of loadings. Their unique deformation mechanism and manufacturing process lead to special multiphysics properties such as variable permeability, synclastic curvature and shape memory. Except for traditional energy absorber stuff, the potential applications of auxetic foams have involved biomedicine, aerospace, smart sensing, etc. However, most of the potential applications are restrained in the theoretical stage due to complicated fabrication and a deficiency of stability. For removing the barrier for practical application, a series of issues remain to be resolved, though the explorations of the improved conversion methodologies and potential applications are fruitful in the past decades. We present here a review article discussing the state-of-the-art for manufacturing, characterization and applications of auxetic foams. We also provide a view of the existing challenges and possible future research directions, aiming to state the perspective and inspire researchers to further develop the field of auxetic foams.

Research paper thumbnail of Tensile Properties Optimization of Date Palm Leaflets Using Taguchi Method

Journal of Natural Fibers, 2021

Lignocellulosic fibers from date palm are one of the most available biomasses without significant... more Lignocellulosic fibers from date palm are one of the most available biomasses without significant valorization in the world. This work makes use of an experimental Taguchi design with three factors...

Research paper thumbnail of ICSST-5, Sharjah, UAE, 1-3 February

Research paper thumbnail of Papers presented at the 2nd Workshop on Auxetics and Related Systems - Bedlewo near Poznan, Poland, 19-23 August 2005

Physica Status Solidi B-basic Solid State Physics, 2007

Research paper thumbnail of Auxetics and Other Systems with “Negative” Characteristics

physica status solidi (b), 2020

The present volume on materials and models with negative Poisson’s ratio, called auxetics, and ot... more The present volume on materials and models with negative Poisson’s ratio, called auxetics, and other systems with “negative” characteristics is the fourteenth focus issue of physica status solidi (b) on this subject. The volume contains twenty four papers. Twenty one of them, on auxetic materials and models, are grouped in three sections: three-dimensional (3D) auxetics, quasi-two-dimensional (Q2D) auxetics, and two-dimensional (2D) auxetics. The remaining papers concern other systems with “negative” characteristics.

Research paper thumbnail of Full-Gradient Optimization of the Vibroacoustic Performance of (Non-)auxetic Sandwich Panels

Transport in Porous Media, 2021

Take-down policy If you believe that this document breaches copyright please contact us providing... more Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Research paper thumbnail of Auxetics and Other Unusual Systems - Preface

Physica Status Solidi B-basic Solid State Physics, 2009

Research paper thumbnail of Vibroacoustic optimization of anti-tetrachiral and auxetic hexagonal sandwich panels with gradient geometry

Smart Materials and Structures, Apr 5, 2016

The work describes the vibroacoustic behavior of anti-tetrachiral and auxetic hexagonal gradient ... more The work describes the vibroacoustic behavior of anti-tetrachiral and auxetic hexagonal gradient sandwich panels using homogenized finite element models to determine the mechanical properties of the auxetic structures, the natural frequencies and radiated sound power level of sandwich panels made by the auxetic cores. The mechanical properties and the vibroacoustic behavior of auxetic hexagonal sandwich panels are investigated as a benchmark. The radiated sound power level of the structure over the frequency range of 0 to 1000 Hz is minimized by modifying the core geometry of the gradient auxetic sandwich panels. Several excitation cases are considered. First-order and random optimization methods are used for the minimization of radiated sound power level of the structures. The results of this study present significant insights into the design of auxetic structures with respect to their vibroacoustical properties.

Research paper thumbnail of Investigation on Microstructure, Tensile Properties and Fatigue Characterization of Porous Date Palm Fiber

Journal of Natural Fibers, Oct 17, 2022

Research paper thumbnail of Open Shape Morphing Honeycombs Through Kirigami

This work presents an "open" and deployable honeycomb configuration created using kirigami-inspir... more This work presents an "open" and deployable honeycomb configuration created using kirigami-inspired cutting and folding techniques. The open honeycomb differs from traditional "closed" honeycomb by its reduced density and its increased flexibility. The exploitation of these characteristics for multifunctional applications is the focus of this work. Potential fields in which the open honeycomb could find application include sandwich panel manufacturing, morphing, and deployable structures.

Research paper thumbnail of A novel centresymmetric honeycomb composite structure

Composite Structures, Dec 1, 2005

In this paper analytical and finite element (FE) simulations are carried out to calculate the in-... more In this paper analytical and finite element (FE) simulations are carried out to calculate the in-plane PoissonÕs ratio and YoungÕs moduli of a new centresymmetric honeycomb configuration under uniaxial loading. Opposite to similar re-entrant honeycomb structures studied in the past, the new re-entrant unit cell topology takes into account possible manufacturing constraints typical of production routes like Resin Transfer Moulding (RTM) or Rapid Prototyping (RP). The results obtained through the analytical and FE analysis show a significant decrease of the PoissonÕs ratio for the internal cell angle between À20°and +20°compared to the classical re-entrant configurations exhibited in literature. The results also show that the presence of edge corners in the unit cell honeycomb configuration gives rise to a cellular structure with enhanced flexibility compared to the classical centresymmetric one. The results obtained by the analytical model show good agreement with the Gibson and Ashby rib-bending model when the honeycomb configuration reduces to the theoretical layout without modifications due to manufacturing constraints.

Research paper thumbnail of ICCST/7, Jan 20 -22

Research paper thumbnail of Investigation of the date palm fiber for green composites reinforcement: Quasi-static and fatigue characterization of the fiber

Industrial Crops and Products, Apr 1, 2020

This study focuses on the chemical and thermo-physical characterization of date palm fiber, which... more This study focuses on the chemical and thermo-physical characterization of date palm fiber, which can be used in the reinforcement of green composites. Alkaline solutions with different concentrations of NaOH (0.5, 1, 2 and 3%) and various immersion times (0.5, 1, 2, 4, 6 and 8h) at room temperature were used to treat fibers obtained from date palm fruit branches. In total, 750 samples were tested, and the results obtained show that the chemical treatment of the fibers can lead to an increase, up to 3 times, of their mechanical properties (strength and Young's modulus) in quasi-static tensile tests. Due to the dispersion in the experimental data, a statistical approach is required to evaluate the mechanical properties. To better understand the phenomena related to the physico-chemical properties of these fibers, several characterization techniques have been used, namely Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction. The data have been compared with results reported in the literature for other lignocellulosic fibers. 摘要 本文主要研究了椰枣纤维的化学和热物理性质，该纤维可用于增强绿色 复合材料，室温下不同浓度的氢氧化钠(0.5%、1%、2%、3%)和不同浸 泡时间(0.5%、1%、2、4、6、8h)的碱性溶液。采用E法处理枣果枝条 纤维.总共测试了750个样品，结果表明，在准静态拉伸试验中，纤维的化 学处理可使其力学性能(强度和杨氏模量)增加3倍.由于实验数据的分散 性，需要一种统计方法来评估力学性能.为了更好地理解与这些纤维物理 化学性质相关的现象，已经使用了几种表征技术，即傅立叶变换红外光 谱(FTIR)、热重分析(TGA)、差示扫描量热法(DSC)和X射线衍射。 这些数据与文献中其他木质纤维素纤维的结果进行了比较.

Research paper thumbnail of Transverse stiffness and strength of Kirigami zero-ν PEEK honeycombs

Composite Structures, Aug 1, 2014

This work describes the manufacture and characterisation of a PEEK-based zero Poisson's ratio hon... more This work describes the manufacture and characterisation of a PEEK-based zero Poisson's ratio honeycomb (SILICOMB) produced using Kirigami-inspired cutting and folding techniques. The flatwise compression and transverse shear properties of the structure are determined through ASTM mechanical testing, and the results compared against commercially available honeycombs, including several other zero Poisson's ratio cellular structures. An analytical model to predict the shear strength is compared to the results. SILICOMB specimens are found to have lower stiffness compared to other honeycomb configurations, but comparable strength. Factors influencing the results and variations to the manufacturing process are discussed.

Research paper thumbnail of Vibroacoustics of 2D gradient auxetic hexagonal honeycomb sandwich panels

Composite Structures, Mar 1, 2018

This paper describes the vibroacoustic behavior of sandwich panels with a novel core topology mad... more This paper describes the vibroacoustic behavior of sandwich panels with a novel core topology made from 2-dimensionally gradient auxetic hexagonal honeycombs. The 2D gradient core enables a tailoring of localized mechanical properties of the sandwich structure in different regions of the panel. A homogenized finite element modeling has been used to

Research paper thumbnail of Shape morphing Kirigami mechanical metamaterials

Scientific Reports, Aug 5, 2016

Research paper thumbnail of In-plane shear moduli of a new curved cell walls honeycomb plates for application in wings of wind turbines

This paper is focused on the identification of the in-plane shear moduli of a new design of auxet... more This paper is focused on the identification of the in-plane shear moduli of a new design of auxetic (negative Poisson's ratio) honeycomb configuration with curved cell walls by using analytical and numerical homogenization techniques. The sensitivity of the shear moduli is determined against the various cell geometry parameters. Good agreement between the analytical and numerical simulations is observed. We show that the specific curved wall honeycomb configuration applicated in plates witch build the structure of the wind turbines proposed in this paper possesses a high flexibly compared to the classical hexagonal cell, This leads to the needs of the wind turbine industry to minimize the weight of the wings and also to have a significant flexibility against the wind and the other external dynamic solicitations.

Research paper thumbnail of On the auxetic potential of 2D networks constructed from chiral building-blocks

Research paper thumbnail of CIMA 04 Boumerdes, Al, 30 November – 2 December

Research paper thumbnail of Characterization of a novel natural cellulosic fiber from Juncus effusus L

Carbohydrate Polymers, Sep 1, 2017

This study aims to assess the morphology and properties of fibers extracted from a wild natural p... more This study aims to assess the morphology and properties of fibers extracted from a wild natural plant largely available in Algeria known as Juncus effusus L. (JE). The morphology and diameter of the fiber bundles extracted from the stem of the JE plant were characterized by optical and scanning electron microscopy. The functional groups of the extracted lignocellulosic JE fibers were studied by FTIR, their thermal degradation behavior was investigated by TGA and their crystallinity was determined using X-ray diffraction technique. In addition, mechanical characterization was carried out using tensile tests on the lignocellulosic fiber in order to evaluate their strength, strain at break and Young's modulus. In view of the dispersion in the obtained experimental results, the latter were analyzed using the Weibull statistical laws with two and three parameters.

Research paper thumbnail of Manufacturing, characteristics and applications of auxetic foams: A state-of-the-art review

Composites Part B: Engineering, 2022

Auxetic foams counter-intuitively expand (shrink) under stretching (compression). These foams can... more Auxetic foams counter-intuitively expand (shrink) under stretching (compression). These foams can exhibit superior mechanical properties such as resistance to shear and indentation, improved toughness and energy absorption (EA) under several types of loadings. Their unique deformation mechanism and manufacturing process lead to special multiphysics properties such as variable permeability, synclastic curvature and shape memory. Except for traditional energy absorber stuff, the potential applications of auxetic foams have involved biomedicine, aerospace, smart sensing, etc. However, most of the potential applications are restrained in the theoretical stage due to complicated fabrication and a deficiency of stability. For removing the barrier for practical application, a series of issues remain to be resolved, though the explorations of the improved conversion methodologies and potential applications are fruitful in the past decades. We present here a review article discussing the state-of-the-art for manufacturing, characterization and applications of auxetic foams. We also provide a view of the existing challenges and possible future research directions, aiming to state the perspective and inspire researchers to further develop the field of auxetic foams.

Research paper thumbnail of Tensile Properties Optimization of Date Palm Leaflets Using Taguchi Method

Journal of Natural Fibers, 2021

Lignocellulosic fibers from date palm are one of the most available biomasses without significant... more Lignocellulosic fibers from date palm are one of the most available biomasses without significant valorization in the world. This work makes use of an experimental Taguchi design with three factors...

Research paper thumbnail of ICSST-5, Sharjah, UAE, 1-3 February

Research paper thumbnail of Papers presented at the 2nd Workshop on Auxetics and Related Systems - Bedlewo near Poznan, Poland, 19-23 August 2005

Physica Status Solidi B-basic Solid State Physics, 2007

Research paper thumbnail of Auxetics and Other Systems with “Negative” Characteristics

physica status solidi (b), 2020

The present volume on materials and models with negative Poisson’s ratio, called auxetics, and ot... more The present volume on materials and models with negative Poisson’s ratio, called auxetics, and other systems with “negative” characteristics is the fourteenth focus issue of physica status solidi (b) on this subject. The volume contains twenty four papers. Twenty one of them, on auxetic materials and models, are grouped in three sections: three-dimensional (3D) auxetics, quasi-two-dimensional (Q2D) auxetics, and two-dimensional (2D) auxetics. The remaining papers concern other systems with “negative” characteristics.

Research paper thumbnail of Full-Gradient Optimization of the Vibroacoustic Performance of (Non-)auxetic Sandwich Panels

Transport in Porous Media, 2021

Take-down policy If you believe that this document breaches copyright please contact us providing... more Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.