Article
Chemistry, Multidisciplinary
Marzia Sara Vaccaro, Francesco Paolo Pinnola, Francesco Marotti de Sciarra, Raffaele Barretta
Summary: The study introduces a new nonlocal approach by swapping the input and output fields involved in the original formulation of Wieghardt, using a displacement-driven nonlocal integral strategy to overcome inherent difficulties and issues. This new approach simplifies the integrodifferential equations governing the elastostatic problem of an inflected elastic slender beam, and involves kinematic, static, and new constitutive boundary conditions.
Article
Mathematics
Francesco Paolo Pinnola, Raffaele Barretta, Francesco Marotti de Sciarra, Antonina Pirrotta
Summary: This paper proposes a consistent nonlocal viscoelastic beam model and investigates a Timoshenko bending problem considering size- and time-dependent effects. A stress-driven nonlocal formulation is used to inspect scale phenomena, and fractional linear viscoelasticity is considered to simulate time-dependent effects. Analytical solutions and application samples are presented, and parametric analyses are provided to show influences of viscoelastic and size effects on mechanical response.
Article
Materials Science, Multidisciplinary
Andrea Caporale, Hossein Darban, Raimondo Luciano
Summary: A novel mathematical formulation is presented for the application of stress-driven nonlocal theory of elasticity to engineering nano-scale problems. The proposed method provides a differential formulation and novel constitutive continuity conditions for determining exact closed-form solutions for nonlocal Euler-Bernoulli beams with loading discontinuities. Several results demonstrate the effectiveness of the proposed method.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2022)
Article
Computer Science, Interdisciplinary Applications
Pei-Liang Bian, Hai Qing
Summary: In this study, a new FEM framework was developed to simulate the mechanical responses of the Euler-Bernoulli beam with a two-phase local/nonlocal mixed model. The model showed efficient convergence, simplicity of expressions, and flexibility in handling various boundary conditions and external loads.
ENGINEERING WITH COMPUTERS
(2023)
Article
Mathematics, Applied
Aurora Angela Pisano, Paolo Fuschi, Castrenze Polizzotto
Summary: Eringen's fully nonlocal elasticity model leads to ill-posed boundary-value problems and boundary effects, but an enhanced model with a regularizing non-homogeneous local phase provides well-posed boundary-value problems without paradoxes. The enhanced model applied to beam bending is equivalent to a sixth order differential equation with variable coefficients and predicts softening size effects consistently. The influence of the length scale parameter on the beam's response is highlighted, showing a wave pattern in the response function delta(lambda) as the parameter increases.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2021)
Article
Mathematics, Applied
Omer Civalek, Busra Uzun, Mustafa Ozgur Yayli
Summary: This study investigates the size-dependent stability analysis of a restrained nanobeam with functionally graded material using nonlocal Euler-Bernoulli beam theory and Fourier series. The research highlights the influences of various parameters on the critical buckling load of the functionally graded nonlocal beam and provides an efficient analytical solution for the buckling response of the nanobeam.
COMPUTATIONAL & APPLIED MATHEMATICS
(2022)
Article
Computer Science, Interdisciplinary Applications
S. Ali Faghidian
Summary: The nonlocal modified gradient theory combines the frameworks of nonlocal integral elasticity and modified strain gradient theory, applied to a beam model. Nanoscopic effects are accommodated, and well-posedness of problems on bounded structural domains is confirmed. Analytical solutions and numerical illustrations are provided for flexural wave behavior in nano-sized beams, and wave propagation in carbon nanotubes is validated through molecular dynamics simulations.
JOURNAL OF COMPUTATIONAL DESIGN AND ENGINEERING
(2021)
Article
Mechanics
Rosa Penna, Luciano Feo, Antonio Fortunato, Raimondo Luciano
Summary: The study investigates the size-dependent flexural nonlinear free vibrations of geometrically imperfect functionally graded nano-beams using the stress-driven nonlocal integral model (SDM). The Galerkin method is applied to derive a nonlinear ordinary differential equation, and the closed form analytical solution of the nonlinear natural flexural frequency for different boundary conditions is established using the Hamiltonian approach. The effects of nonlocal scale parameter and initial axial tension force on fundamental frequencies are examined and compared with results obtained from Eringen's nonlocal model. The study demonstrates that the nonlinear approach based on nonlocal stress model is effective in capturing the dynamical responses of nano-beams and is advantageous for the design and optimization of nano-scaled components in NEMS.
COMPOSITE STRUCTURES
(2021)
Article
Mechanics
Nachman Malkiel, Oded Rabinovitch, Isaac Elishakoff
Summary: This study focuses on two general solutions for a simply supported linear elastic Bernoulli-Euler beam with stochastic bending flexibility under deterministic loading, considering trapezoidally and sinusoidally distributed loads. The derivation of stochastic characteristics for random beams under a sinusoidal load is useful due to the expandability to generally distributed loads by a Fourier sine series expansion. Numerical results illustrate the effect of stochasticity on the beam's properties and its flexural response.
Article
Engineering, Multidisciplinary
Francesco Paolo Pinnola, Marzia Sara Vaccaro, Raffaele Barretta, Francesco Marotti de Sciarra
Summary: The bending behavior of systems of straight elastic beams at different scales is investigated using stress-driven nonlocal continuum mechanics, and an effective computational methodology is developed to accurately account for long-range interactions.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2021)
Article
Engineering, Mechanical
M. Faraji Oskouie, R. Ansari, H. Rouhi
Summary: In this study, a comprehensive model is proposed to capture the combined effects of strain gradient and nonlocality on the static bending response of nanoscopic beams. By using numerical solution approaches, the deflection of nanobeams under various end conditions is obtained and the simultaneous influences of different theories on the static bending response are explored through selected numerical results. The developed size-dependent model has the ability to consider strain gradient and nonlocal influences in the most general way.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2021)
Article
Nanoscience & Nanotechnology
Indronil Devnath, Mohammad Nazmul Islam, Minhaj Uddin Mahmood Siddique, Abdelouahed Tounsi
Summary: This paper presents explicit analytical equations for computing the static displacements of nanobeams using the nonlocal elasticity theory of Eringen within the framework of Euler Bernoulli and Timoshenko beam theories. The derived equations match exactly with those obtained by other analytical methods and the computed results are in excellent agreement with those obtained by other numerical methods, validating the accuracy of the proposed method.
ADVANCES IN NANO RESEARCH
(2022)
Article
Mechanics
Chengyun Long, Bing Zhao, Jian Chen, Tao Liu, Xulong Peng, Hui Peng, Xinhua Yang
Summary: A new size-dependent thermal buckling model based on modified gradient elasticity is presented in this study. Numerical examples of different supported beams show that the smaller the beam size, the bigger the critical buckling temperature rise, and the internal length scales significantly affect the critical buckling temperature rises. The differences in critical buckling temperature rises caused by choosing different higher-order boundary conditions cannot be ignored.
ARCHIVE OF APPLIED MECHANICS
(2021)
Article
Mechanics
Bing Zhao, Lin Liu, Jian Chen, Chengyun Long, Xulong Peng, Huanxin Yi, Moyu Zhao
Summary: A new size-dependent thermoelastic damping model is proposed in this study to investigate the behavior of micro-beams with thermoelastic damping. The results indicate a significant size effect of thermoelastic damping in micro-beams, with the critical thickness of the beam related to the internal length scale. The proposed model is characterized by its clear physical interpretation and simple form, providing theoretical guidance for designing high-quality micro/nano-electromechanical resonators.
ARCHIVE OF APPLIED MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
A. Czekanski, V. V. Zozulya
Summary: New higher-order models based on the linear theory of nonlocal elasticity are developed for plane rods and beams. These models are used to analyze tension-compression and transverse bending modes of nonlocal rod and beam vibration. By considering nonlocal effects, the proposed models can be applied to vibration analysis of rods and beams at macroscales, microscales, and nanoscales.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2021)
Article
Materials Science, Multidisciplinary
Sabrina Vantadori, Jesus Vazquez Valeo, Andrea Zanichelli, Andrea Carpinteri, Raimondo Luciano
Summary: This paper simulates an experimental campaign on shot peened Ti6Al4V specimens under fretting fatigue, using the Carpinteri et al. criterion. The study shows the effect of fatigue loading on material properties.
INTERNATIONAL JOURNAL OF FRACTURE
(2022)
Editorial Material
Chemistry, Multidisciplinary
Raffaele Barretta, Domenico De Tommasi, Fernando Fraternali
Article
Mathematics
Francesco Paolo Pinnola, Raffaele Barretta, Francesco Marotti de Sciarra, Antonina Pirrotta
Summary: This paper proposes a consistent nonlocal viscoelastic beam model and investigates a Timoshenko bending problem considering size- and time-dependent effects. A stress-driven nonlocal formulation is used to inspect scale phenomena, and fractional linear viscoelasticity is considered to simulate time-dependent effects. Analytical solutions and application samples are presented, and parametric analyses are provided to show influences of viscoelastic and size effects on mechanical response.
Article
Mechanics
Francesco Paolo Pinnola, Marzia Sara Vaccaro, Raffaele Barretta, Francesco Marotti de Sciarra, Giuseppe Ruta
Summary: A challenging task in nonlocal continuum mechanics is to formulate constitutive relations for well-posed structural problems. Strategies such as using local/nonlocal mixtures of elasticity and integral models have been adopted to overcome the limitations of Eringen's pure nonlocal theory in nanostructures. This paper proposes a consistent formulation of a nonlocal elastic foundation for a Bernoulli-Euler beam, where the transverse displacements are a convex combination of reaction-driven local and nonlocal phases governed by Winkler and Wieghardt laws, respectively. The proposed integral mixture is proven to be equivalent to a more convenient differential problem with nonlocal boundary conditions, which can effectively solve nonlocal problems of beams on mixture reaction-driven continuous foundation.
ARCHIVE OF APPLIED MECHANICS
(2023)
Article
Metallurgy & Metallurgical Engineering
Filip Nikolic, Ivan Stajduhar, Marko Canadija
Summary: This research focuses on using convolutional neural networks (CNNs) to detect porosity defects in aluminum alloys. Through training and testing with various aluminum alloy samples, the proposed custom CNN model demonstrates accurate prediction of porosity defects with a classification accuracy of 94%.
INTERNATIONAL JOURNAL OF METALCASTING
(2023)
Article
Mechanics
Ada Amendola, Vittorio Zampoli, Raimondo Luciano
Summary: This paper discusses the modeling problem of nanobeams that dissipate thermal energy by radiation. The behavior of nonlocal nanobeams based on Euler-Bernoulli assumptions in a one-dimensional case is studied. With these assumptions, a thermoelastic model that considers the effects of thermal energy radiation to the external environment is proposed, using an extension of the GN-II theory. Wave-form solutions are used to further analyze the formulated theoretical model and highlight the presence of dissipative effects.
Article
Mechanics
Y. Zhu, A. Fascetti, L. Feo, A. S. Mosallam, R. Penna
Summary: The research focuses on the experimental characterization and numerical simulation of pultruded Glass Fiber-Reinforced Polymer (GFRP) structural elements, specifically on enhancing the ultimate capacity of Web-Flange Junctions (WFJs). The study includes an experimental campaign on as-manufactured I-beam specimens and a numerical investigation on different stiffeners' arrangements. The results demonstrate the importance of external stiffeners in improving the strength and stiffness of GFRP I-beams.
COMPOSITE STRUCTURES
(2023)
Article
Thermodynamics
Giovanni Romano, Raffaele Barretta, Marina Diaco
Summary: In Continuum Mechanics, Nanson formula establishes the relationship between the product of area and unit normal vectors on corresponding surfaces in two configurations of a 3D body. By elaborating on the Euler-Jacobi volume change formula, equivalent expressions of Nanson formula are obtained. The meaning and limitations of Nanson formula are highlighted. It is shown that the assumption of using Nanson formula to impose equilibrium in a reference shape of the body is incorrect. A variational formulation of evolutive equilibrium in spacetime is proposed, and finite step elastic problems guided by control algorithms in computational procedures are illustrated. The impossibility of achieving referential equilibrium in Nonlinear Continuum Mechanics is demonstrated through step-by-step iterative methods of solution of nonlinear structural problems and simple counterexamples.
CONTINUUM MECHANICS AND THERMODYNAMICS
(2023)
Article
Engineering, Multidisciplinary
Raffaele Barretta, Andrea Caporale, Raimondo Luciano, Marzia Sara Vaccaro
Summary: Nonlocal continuum theories are applied to investigate the mechanics of nanobeams under non-smooth fields. The study starts with the general formulation of elasticity in nanobeams based on the abstract form of nonlocal gradient theory. The equivalent differential problem is derived to determine the constitutive law, and the simplest constitutive interface conditions not involving spatial convolutions are established.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2023)
Article
Engineering, Multidisciplinary
Rosa Penna
Summary: This paper investigates the bending response of Bernoulli-Euler nanobeams made of a functionally graded material with different cross-sectional shapes. A stress-driven model incorporating surface energy effects is used. The nanobeam consists of a bulk volume and a surface layer perfectly adhered to the bulk continuum. The nonlocal governing equations of the elastostatic bending problem are derived and the main results of a parametric investigation are presented.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2023)
Article
Mathematics, Interdisciplinary Applications
Francesco Fabbrocino, Serena Saitta, Riccardo Vescovini, Nicholas Fantuzzi, Raimondo Luciano
Summary: This research focuses on solving the strain gradient thin plate theory problem using a meshless method, and evaluates the numerical solutions by optimizing the shape parameters. Numerical benchmarks, stability, and comparison with existing literature are discussed.
MATHEMATICAL AND COMPUTATIONAL APPLICATIONS
(2022)
Proceedings Paper
Engineering, Civil
Attilio Quadrino, Marco Damiani, Rosa Penna, Luciano Feo, Nicola Nistico
Summary: In a pilot project at Salerno University, a preliminary design of a pedestrian FRP bridge was conceived. The design is a cable stayed bridge that utilizes PGFRP and PCFRP materials for assembly and incorporates an optimized anchoring system for the cables. The design takes into consideration pedestrian comfort, joints, and cable system, with dynamic effects from wind action still under study.
10TH INTERNATIONAL CONFERENCE ON FRP COMPOSITES IN CIVIL ENGINEERING (CICE 2020/2021)
(2022)
Proceedings Paper
Engineering, Industrial
Luciano Feo, Enzo Martinelli, Rosa Penna, Marco Pepe
Summary: In most European countries, buildings constructed in the first decades after WWII are predominantly reinforced concrete structures. Due to their non-compliance with modern safety and energy efficiency standards, these buildings require upgrades to meet current regulations. However, the high cost of upgrading existing structures is often a challenge for owners, particularly in the case of private buildings.
ADVANCED TECHNOLOGIES FOR HUMANITY
(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)
