Articoli di riviste: "Embedded fiber model"

1

Gu, X., e R. J. Young. "Deformation Micromechanics in Model Carbon Fiber Reinforced Composites Part II: The Microbond Test". Textile Research Journal 67, n. 2 (febbraio 1997): 93–100. http://dx.doi.org/10.1177/004051759706700204.

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Raman spectroscopy is used to study the deformation micromechanics of the microbond test for a carbon fiber epoxy resin system using surface-treated and untreated PAN-based fibers, and the results are compared with those of the conventional microbond test. Fiber strain and interfacial shear stress (ISS) are mapped along the embedded regions of fibers during the test using the Raman technique, and the maximum value of ISS, τmax, is determined. The maximum τmax value can be used to characterize the strength of the fiber matrix interface, and it is higher for specimens with surface-treated fibers. The apparent value of interfacial shear strength, τ a, determined from conventional analysis of the microbond test, is a function of the embedded fiber length. However, the value of τ a extrapolated to zero embedded length, τ i, is comparable to the maximum ISS value, τmax, determined from the Raman analysis. The influence on the results of radial compression and geometric factors, such as droplet shape and size and separation of the knife edges, is also discussed.

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Her, Shiuh Chuan, e Bo Ren Yao. "Stress Analysis of Composite Material Embedded with Optical Fiber Sensor Subjected to In-Plane Shear". Advanced Materials Research 139-141 (ottobre 2010): 137–40. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.137.

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Optical fiber sensor with small size, light weight and immunity to electromagnetic interference can be embedded and integrated into the host material to form an ideally smart structure system. One must recognize that optical fibers are foreign entities to the host structure, therefore will induce high stress state in the vicinity of the embedded sensor irrespective of the small size of the fiber. To address this concern, present paper focuses the attention on constituent interaction between the optical fiber, coating, matrix and host material. An analytical model to predict the stress fields in the vicinity of the embedded optical fiber is presented. The theoretical development is based on the four concentric cylinders model which represents the optical fiber, protective coating, matrix and host material, respectively. The host material is considered to be a composite with reinforced fiber parallel to the optical fiber. In this investigation, the host structure is subjected to in-plane shear loading. The effects of the coating and host material on the stress distribution in the vicinity of the embedded optical fiber are presented through a parametric study.

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Ho, Ha Vinh, Eunsoo Choi e Jun Won Kang. "Analytical bond behavior of cold drawn SMA crimped fibers considering embedded length and fiber wave depth". REVIEWS ON ADVANCED MATERIALS SCIENCE 60, n. 1 (1 gennaio 2021): 862–83. http://dx.doi.org/10.1515/rams-2021-0066.

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Abstract The NiTi SMA fibers were cold drawn to introduce prestrain, and then, they were made to crimped fibers with various wave depths. The recovery stress was measured, which was useful for closing the cracks in fiber-reinforced concrete. The pullout behaviors were also examined considering the existing recovery stress, and it is found that the recovery stress did not influence so much on the pullout behavior. According to the pullout results, a parametric study used a finite element analyzing (FEA) model to quantify the cohesive surface model’s parameters and the value of the friction coefficient. Then, the developed model is used to investigate the crimped fiber’s pullout behavior with various embedded lengths and wave depths. When the fiber in the elastic range, the peak stresses significantly raise due to increasing embedded waves; they show a linear relationship. After the yield of the SMA fiber, the peak stresses are also a function of embedded waves; however, the increasing trend is slow down. Concerning the cost, the even distribution of the fiber, and for guaranteeing the fiber experiences the pulling out, it is recommended that the embedded lengths and corresponding wave depths should be designed to avoid the yield.

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Chung, Ilsup, e Y. Jack Weitsman. "Model for the Micro-Buckling/Micro-Kinking Compressive Response of Fiber-Reinforced Composites". Applied Mechanics Reviews 47, n. 6S (1 giugno 1994): S256—S261. http://dx.doi.org/10.1115/1.3124419.

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This article focuses on the effects that non-uniform fiber spacings have on the compressive response of composites. The above type of imperfection is included in a model which incorporates initial fiber misalignments and accounts for non-linear shear response of the matrix and shear-deformable fibers. It is shown that the disparate response of fibers embedded within matrix layers of different thicknesses results in reduced levels of compressive strengths and leads to failure modes which contain discontinuities in the fiber shear strains.

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Liang, Xiaodong, Kai Li e Shengqiang Cai. "Drying-Induced Deformation in Fiber-Embedded Gels to Mimic Plant Nastic Movements". International Journal of Applied Mechanics 07, n. 02 (aprile 2015): 1550016. http://dx.doi.org/10.1142/s1758825115500167.

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Pinecone scales and seedpod valves can deform in response to environmental humidity change, which is categorized as nastic movements. In this article, inspired by their tissue structure, we use fiber-embedded gels to model the nastic movements of pinecone scales and seedpod valves. In the model, stiffer and less swellable fibers orient inhomogeneously in the gel matrix. Depending on the arrangement of fibers, the gel matrix may bend or twist when it shrinks, caused by the decrease of environmental humidity. Our simulations demonstrate the possibilities of achieving different deformation modes in fiber-embedded gels through initially specified fiber arrangements. The numerical modeling methods presented in the article may find their applications in biomimetic designs with responsive gels.

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Gao, Jian Hong, e Xiao Xiang Yang. "Evaluation of 3D Embedded Element Technique in the Finite Element Analysis for the Composite". Key Engineering Materials 801 (maggio 2019): 65–70. http://dx.doi.org/10.4028/www.scientific.net/kem.801.65.

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RVE combined with finite element analysis (FEA) is a very popular method to predict the mechanical property of the composite reinforced by short fibers. In the conventional method, generally the “tie” approach is used. By this method, the FE model with high fiber aspect ratio can not be achieved and the non-convergence of the numerical calculation may appear because of the complex mesh. The embedded element techinique is considered to be a replaceable method . Using this method, the mechanical behavior of composite with high fiber aspect ratio would be simulated. Therefore, in this study, the 3D solid element was employed for the FE model with multi cylinder particles. The comparisions of the Mise stress and the displacement between the embedded and conventional method indicate that compared with the stress transfer, the simulated result of composite stiffness is more accurate. In addition, the effects of model size, fiber orientated angle, fiber volume fraction and fiber aspect ratio were investigated. The numerical results were compared with the Mori-Tanaka model and the good agreements verify the applicability of the embedded element technique we studied in this paper.

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Wren, T. A. L., e D. R. Carter. "A Microstructural Model for the Tensile Constitutive and Failure Behavior of Soft Skeletal Connective Tissues". Journal of Biomechanical Engineering 120, n. 1 (1 febbraio 1998): 55–61. http://dx.doi.org/10.1115/1.2834307.

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We propose a microstructural model for the uniaxial tensile constitutive and failure behavior of soft skeletal connective tissues. The model characterizes the tissues as two-phase composites consisting of collagen fibers embedded in ground substance. Nonlinear toe region behavior in the stress versus strain curve results from the straightening of crimped fibers and from fiber reorientation. Subsequent linear behavior results from fiber stretching affected by fiber volume fraction, collagen type, crosslink density, and fiber orientation. Finally, the tissue fails when fibers successively rupture at their ultimate tensile strain. We apply the model to tendon, meniscus, and articular cartilage. The model provides a consistent approach to modeling the tensile behavior of a wide range of soft skeletal connective tissues.

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Gao, Jian Hong, Xiao Xiang Yang e Li Hong Huang. "Application of Embedded Element in the Short Fiber Reinforced Composite". Key Engineering Materials 774 (agosto 2018): 241–46. http://dx.doi.org/10.4028/www.scientific.net/kem.774.241.

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The finite element analysis (FEA) is a numerical method for predicting the mechanical property of short fiber reinforced composite usefully. However, as we know, there is always a “jamming” limit when generating fiber architecture expecially in the cases of high volume fraction and high aspect ratio of short fiber. Even if the volume fraction and aspect ratio in finite element model meet the practical requirements, the problem of mesh deformity will always occur which would lead to unconverge of numerical computation. In this work, embedded element technique which will help to reduce the probability of the above two problems is employed to establish the finite element model of short fiber reinforced composite. The effect of edge size, thickness and mesh density of FE models on the elastic modulus were investigated. Numerical results show that the value of elastic modulus mainly depend on the edge size and fiber amount of FE model while the effect of thickness can be neglected. The elastic modulus takes to converge for high element number. An inverse method is proposed to calculate volume fraction of short fibers, by which numerical results agree well with the calculation results of empirical formula based on Halpin-Tsai equation.

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Huang, Yizhe, Zhifu Zhang, Chaopeng Li, Kuanmin Mao e Qibai Huang. "Modal Performance of Two-Fiber Orthogonal Gradient Composite Laminates Embedded with SMA". Materials 13, n. 5 (2 marzo 2020): 1102. http://dx.doi.org/10.3390/ma13051102.

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A gradient composite laminate that was composed of two-phase fibers, a shape memory alloy (SMA), and graphite was prepared to investigate modal performance and improve vibration behavior. The stress-strain relation of the single-layer composite plates was derived from Kirchhoff thin plate theory and the material constitutive of the SMA. A gradient distribution model and the eigenvalue equations of gradient composite laminates were developed. The influence of the fiber component content gradient distribution, pre-strain, the two-phase fiber volume fraction, and geometric parameters on the modal performance was analyzed. This study provides a method to avoid the structural resonance of composite laminates that are embedded with an SMA through the gradient distribution of two-phase fiber content that leads to the interaction of the material properties.

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Zulkarnain, Muhammad, Zaimi Zainal Mukhtar e Ikhwan Yusof. "Effect of Steel Fiber Reinforced in FRP Confined Concrete by Using Numerical Analysis". Key Engineering Materials 879 (marzo 2021): 202–12. http://dx.doi.org/10.4028/www.scientific.net/kem.879.202.

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The models are predicting and analyzing on compressive and flexural testing by considering fiber reinforcement embedded in confinement concrete. In this work, steel 4340 fiber with high aspect ratio was developed in unique random spline shape and randomly disperse in confinement concrete. Fibers designed in 15.5mm of average length and amount were varied in range of 50 to 200 and 250 to 1000 for compressive and flexural testing, respectively. Both varied orientation and random dispersion of fiber were developed using MATLAB before embedded and analyzed in Ansys Workbench. The finite element model was validated in initial results on plain concrete prior study in influence of confining and fibers to structure. The model proposed showed that confining reinforcement increasing ductility and large deflections in structure testing. In addition, fibers as reinforcement slightly increases in strength for both compressive and flexural in certain number. These method reinforcement was help warning of failure prior to complete failure that use in construction material.

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Cong, Ding, Guo Liping, Ren Jinming, Wang Yongming, Li Xinyu, Gao Yuan, Liu Wanpeng e Li Ruize. "A Modified Fiber Bridging Model for High Ductility Cementitious Composites Based on Debonding-Slipping Rupture Analysis". Advances in Materials Science and Engineering 2022 (24 maggio 2022): 1–16. http://dx.doi.org/10.1155/2022/1461318.

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Modified micromechanical bridging model is established with consideration of the fiber rupture effect at debonding and slipping stages. The bridging model includes the debonding and slipping rupture of fibers and establishes the fiber/matrix interfacial parameters (friction τ 0 , chemical bonding force G d , slip-hardening coefficient β ). A different interfacial bonding can cause fiber rupture. The influence of the interfacial conditions on the fiber rupture risk was investigated. In the modified bridging model, the effective bridging stress, the debonding rupture stress, and the slipping rupture stress were clearly identified. Finally, single-fiber pullout tests with different embedded lengths were carried out to validate the bridging model. The relationship between the fiber bridging stress and the crack opening predicted by the bridging model was consistent with the experimental results. This modified micromechanical bridging model can be used to quantitatively calculate the actual fiber bridging capacity and to predict the ductility of the high ductility cementitious composites reinforced by different types of fibers.

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Varna, Janis, Lin Qi Zhuang, Andrejs Pupurs e Zoubir Ayadi. "Growth and Interaction of Debonds in Local Clusters of Fibers in Unidirectional Composites during Transverse Loading". Key Engineering Materials 754 (settembre 2017): 63–66. http://dx.doi.org/10.4028/www.scientific.net/kem.754.63.

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Fiber/matrix debonding in transverse tensile loading of a unidirectional composite is analyzed calculating energy release rate (ERR) for interface crack propagation. Non-uniform fiber distribution (local hexagonal fiber clustering) is assumed in the model. The matrix region containing the central fiber with the debond and the 6 surrounding fibers is embedded in a large block of homogenized composite which has the same fiber content as the region analyzed explicitly. Some of the fibers surrounding the central fiber may also have a debond. The effect of the local clustering and of the presence of other debonds on magnification of the ERR is analyzed.

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Akbari Baghal, Amir Ebrahim, Ahmad Maleki e Ramin Vafaei. "On the Pull-out Behavior of Hooked-End Shape Memory Alloys Fibers Embedded in Ultra-High Performance Concrete". International Journal of Engineering and Technology Innovation 11, n. 4 (23 luglio 2021): 265–77. http://dx.doi.org/10.46604/ijeti.2021.7060.

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This study presents a three-dimensional non-linear finite element investigation on the pull-out behavior of straight and hooked-end Shape Memory Alloys (SMA) and steel fibers embedded in Ultra-High Performance Concrete (UHPC) using a single fiber pull-out model. A bilinear cohesive zone model is used to characterize the interfacial traction separation relationships. The Concrete Damage Plasticity (CDP) model is used to simulate UHPC, and the mechanical behavior is obtained through experimental tests. Parametric studies are conducted to evaluate the effects of fiber materials, fiber diameters, and hook angles on the load-displacement behavior. A good agreement between the numerical and experimental results is obtained. It is found that the hooked-end fibers with a smaller diameter and a hook angle of 40° can be a better choice for structural application. Furthermore, it is observed that the use of SMA fibers significantly improves the pull-out performance between fibers and UHPC.

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Yi, Duo, Min Zhang, Lijuan Gu, Jianming Yang e Wenhui Yu. "Finite element analysis of fiber optic embedded in thermal spray coating". Journal of Intelligent Material Systems and Structures 29, n. 5 (22 luglio 2017): 896–904. http://dx.doi.org/10.1177/1045389x17721057.

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This study aims to evaluate the thermomechanical behavior of a new composite structure using finite element method. The composite structure consists of the substrate and the thermal spray coating with embedded fiber optic. The temperature evolution of the composite estimated by the finite element model shows good agreement with the experimental recording, which confirms the justifiability of model initialization, and then, the thermal results are applied for the following mechanical analysis. The stress distribution and the variation in refractive index of the embedded fiber are investigated. The results show that the stress level suffered by the embedded fiber is much lower than the yield strength, and the variation in refractive index of the embedded fiber has an insignificant effect on optical transmission, which ensures a good embedding quality of the fiber optic.

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Zhou, Chunhua, Changhao Chen, Zilong Ye, Qi Wu e Ke Xiong. "Multi-Directional Strain Measurement in Fiber-Reinforced Plastic Based on Birefringence of Embedded Fiber Bragg Grating". Sensors 24, n. 19 (24 settembre 2024): 6190. http://dx.doi.org/10.3390/s24196190.

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Embedded fiber Bragg gratings are increasingly applied for in-situ strain measurement in fiber-reinforced plastics, integral to high-end aerospace equipment. Existing research primarily focuses on in-plane strain measurement, limited by the fact that fiber Bragg gratings are mainly sensitive to axial strain. However, out-of-plane strain measurement is equally important for comprehending structural deformation. The birefringence of fiber Bragg gratings shows promise for addressing this problem; yet, the strain transfer relationship between composites and optical fibers, along with the decoupling method for multi-directional strains, remains inadequately explored. This study introduces an innovative method for multi-directional strain measurement in fiber-reinforced plastics using the birefringence of a single-fiber Bragg grating. The strain transfer relationship between composites and embedded optical fibers was derived based on Kollar’s analytical model, leading to the development of a multi-directional strain decoupling methodology. This method was experimentally validated on carbon fiber/polyetherimide laminates under thermo-mechanical loading. Its reliability was confirmed by comparing experimental results and finite element simulations. These findings significantly broaden the application scenarios of fiber Bragg gratings, advancing the in-situ measurement technology crucial for the next generation of high-end aerospace equipment.

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Prabhugoud, Mohanraj, e Kara Peters. "Finite element model for embedded fiber Bragg grating sensor". Smart Materials and Structures 15, n. 2 (23 febbraio 2006): 550–62. http://dx.doi.org/10.1088/0964-1726/15/2/038.

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Matveenko, V. P., e G. S. Serovaev. "Numerical Investigation of Stress-Strain State Effects on Strain Measurements with Fiber Bragg Grating Sensors". Journal of Physics: Conference Series 2701, n. 1 (1 febbraio 2024): 012079. http://dx.doi.org/10.1088/1742-6596/2701/1/012079.

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Abstract This study investigates the behaviour of resonant wavelengths of Fiber Bragg Gratings (FBG) inscribed within optically isotropic fibers under transverse loading, both in free and embedded conditions. A numerical-analytical approach is employed, utilizing the finite element method to calculate strain tensor components in the optical fiber core, followed by an analytical determination of resonant wavelengths and reflected FBG spectrum shape. The research demonstrates the influence of the ratio of host material and optical fiber elastic moduli on the birefringence level in FBG area under transversal loading. Based on analytical model of FBG spectrum simulation the discrepancy between analytically calculated and experimentally recorded resonant wavelength shifts in FBG embedded within isotropic material under varying transverse load levels is demonstrated.

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Chegini, Salman, e Stephen J. Ferguson. "THE ROLE OF COLLAGEN FIBERS IN CARTILAGE MECHANICS: A FIBER-EMBEDDED, POROVISCOELASTIC MODEL". Journal of Biomechanics 41 (luglio 2008): S174. http://dx.doi.org/10.1016/s0021-9290(08)70174-x.

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SCHLANGEN, ERIK, e ZHIWEI QIAN. "3D MODELING OF FRACTURE IN CEMENT-BASED MATERIALS". Journal of Multiscale Modelling 01, n. 02 (aprile 2009): 245–61. http://dx.doi.org/10.1142/s1756973709000116.

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In this article, a 3D lattice model is presented to simulate fracture in cement-based materials. In the paper, two applications are shown. The first application is modeling heterogeneous materials containing particle embedded in a matrix. A method is shown for coupling 3D information on the material structure obtained with CT-scanning to the material properties in the model. In the second application, fracture in fiber cement-based materials is modeled. Fibers are explicitly implemented as separate elements connected to the cement matrix via special interface elements. With the model, multiple cracking and ductile global behavior are simulated of the composite material. Variables in the model are the fiber dimensions and properties, the fiber volume in the composite, the bond behavior of fibers and matrix, and the cement matrix properties. These properties can be obtained by testing. Some examples of tests are given in the paper. The model can be used as a design tool for creating fiber (cement-based) composites with any desired mechanical behavior.

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Pise, Mangesh, Dominik Brands e Jörg Schröder. "Development and Calibration of a Phenomenological Material Model for Steel-Fiber-Reinforced High-Performance Concrete Based on Unit Cell Calculations". Materials 17, n. 10 (10 maggio 2024): 2247. http://dx.doi.org/10.3390/ma17102247.

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A phenomenological material model has been developed to facilitate the efficient numerical analysis of fiber-reinforced high-performance concrete (HPC). The formulation integrates an elasto-plastic phase-field model for simulating fractures within the HPC matrix, along with a superimposed one-dimensional elasto-plasticity model that represents the behavior of the embedded fibers. The Drucker–Prager plasticity and one-dimensional von-Mises plasticity formulations are incorporated to describe the nonlinear material behavior of both the HPC matrix and the fibers, respectively. Specific steps are undertaken during the development and calibration of the phenomenological material model. In the initial step, an experimental and numerical analysis of the pullout test of steel fibers embedded in an HPC matrix is conducted. This process is used to calibrate the micro-mechanical model based on the elasto-plastic phase-field formulation for fracture. In the subsequent step, virtual experiments based on an ellipsoidal unit cell, also with the resolution of fibers (used as a representative volume element, RVE), are simulated to analyze the impact of fiber–matrix interactions and their physical properties on the effective material behavior of fiber-reinforced HPC. In the final step, macroscopic boundary value problems (BVPs) based on a cuboid are simulated on a single scale using the developed phenomenological material model. The resulting macroscopic stress–strain characteristics obtained from both types of simulations, namely simulations of virtual experiments and macroscopic BVPs, are compared. This comparison is utilized for the calibration of material parameters to obtain a regularized solution and to assess the effectiveness of the presented phenomenological material model.

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Her, Shiuh Chuan, e Chang Yu Tsai. "Strain Analysis of an Embedded Optical Fiber Sensor". Key Engineering Materials 467-469 (febbraio 2011): 279–82. http://dx.doi.org/10.4028/www.scientific.net/kem.467-469.279.

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Optical fiber sensors with light weight, small dimension and immunity to electromagnetic interference are widely used in structural health monitoring device. In this investigation, a theoretical model of the strain transferred from the host material to the embedded optical fiber is developed to reveal the differential strains between the optical fiber sensor and host material. The theoretical predictions are validated with the numerical analysis using the finite element method. The percentage of strain in the host material actually transferred to the optical fiber is dependent on the bonding characteristics such as adhesive layer, protective coating and host material. Parametric study shows that the larger of the host material the more strain is transferred to the optical fiber.

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Tamin, M. N., e H. Ghonem. "Fatigue Damage Mechanisms of Bridging Fibers in Titanium Metal Matrix Composites1". Journal of Engineering Materials and Technology 122, n. 4 (4 maggio 2000): 370–75. http://dx.doi.org/10.1115/1.1288770.

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This paper investigates the fatigue damage mechanisms of SiC fibers bridging a fatigue crack in unidirectional reinforced titanium matrix composites. For this purpose, an experimental/computational fiber fracture model is developed on the basis of the occurrence of two damage events taking place along a bridging fiber. These events are the time-dependent evolution of axial stresses and the simultaneous strength degradation of the fiber due to cyclic-related damage processes. The stress evolution in a fiber is calculated using the finite element method employing a cylinder model of a fiber embedded in a cracked matrix phase. The model considers the visco-plastic behavior of the matrix phase at elevated temperature loadings. The failure strength of the as-received SiC fiber are determined through a series of monotonic tension, residual fatigue strength and fatigue-life tests performed on SiC fibers at different temperatures. In order to take into account the notch-like effects resulting from the presence of fiber coating cracks and possible deflection of fiber/matrix interfacial cracks, the fatigue strength of the as-received SiC fiber was modified using elastic stress localization. The resulting fatigue strength of bridging fibers was found to be about 56 percent less than the corresponding strength of as-received fibers. The fiber stress evolution curve and the modified fatigue strength curve were then combined to predict the life of bridging fibers. Results of the model are compared with those obtained experimentally for bridging fibers in SiC/Timetal-21S composite subjected to load conditions including low and high loading frequency at 500 and 650°C. [S0094-4289(00)01804-1]

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Lindner, Markus, Andrea Stadler, Georg Hamann, Bennet Fischer, Martin Jakobi, Florian Heilmeier, Constantin Bauer, Wolfram Volk, Alexander W. Koch e Johannes Roths. "Fiber Bragg Sensors Embedded in Cast Aluminum Parts: Axial Strain and Temperature Response". Sensors 21, n. 5 (1 marzo 2021): 1680. http://dx.doi.org/10.3390/s21051680.

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In this study, the response of fiber Bragg gratings (FBGs) embedded in cast aluminum parts under thermal and mechanical load were investigated. Several types of FBGs in different types of fibers were used in order to verify general applicability. To monitor a temperature-induced strain, an embedded regenerated FBG (RFBG) in a cast part was placed in a climatic chamber and heated up to 120 ∘C within several cycles. The results show good agreement with a theoretical model, which consists of a shrink-fit model and temperature-dependent material parameters. Several cast parts with different types of FBGs were machined into tensile test specimens and tensile tests were executed. For the tensile tests, a cyclic procedure was chosen, which allowed us to distinguish between the elastic and plastic deformation of the specimen. An analytical model, which described the elastic part of the tensile test, was introduced and showed good agreement with the measurements. Embedded FBGs - integrated during the casting process - showed under all mechanical and thermal load conditions no hysteresis, a reproducible sensor response, and a high reliable operation, which is very important to create metallic smart structures and packaged fiber optic sensors for harsh environments.

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Kalaitzidou, Chrysovalantou, Georgios Grekas, Andreas Zilian, Charalambos Makridakis e Phoebus Rosakis. "Compressive instabilities enable cell-induced extreme densification patterns in the fibrous extracellular matrix: Discrete model predictions". PLOS Computational Biology 20, n. 7 (1 luglio 2024): e1012238. http://dx.doi.org/10.1371/journal.pcbi.1012238.

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We present a new model and extensive computations that explain the dramatic remodelling undergone by a fibrous collagen extracellular matrix (ECM), when subjected to contractile mechanical forces from embedded cells or cell clusters. This remodelling creates complex patterns, comprising multiple narrow localised bands of severe densification and fiber alignment, extending far into the ECM, often joining distant cells or cell clusters (such as tumours). Most previous models cannot capture this behaviour, as they assume stable mechanical fiber response with stress an increasing function of fiber stretch, and a restriction to small displacements. Our fully nonlinear network model distinguishes between two types of single-fiber nonlinearity: fibers that undergo stable (supercritical) buckling (as in previous work) versus fibers that suffer unstable (subcritical) buckling collapse. The model allows unrestricted, arbitrarily large displacements (geometric nonlinearity). Our assumptions on single-fiber instability are supported by recent simulations and experiments on buckling of individual beams with a hierarchical microstructure, such as collagen fibers. We use simple scenarios to illustrate, for the first time, two distinct compressive-instability mechanisms at work in our model: unstable buckling collapse of single fibers, and snap-through of multiple-fiber groups. The latter is possible even when single fibers are stable. Through simulations of large fiber networks, we show how these instabilities lead to spatially extended patterns of densification, fiber alignment and ECM remodelling induced by cell contraction. Our model is simple, but describes a very complex, multi-stable energy landscape, using sophisticated numerical optimisation methods that overcome the difficulties caused by instabilities in large systems. Our work opens up new ways of understanding the unique biomechanics of fibrous-network ECM, by fully accounting for nonlinearity and associated loss of stability in fiber networks. Our results provide new insights on tumour invasion and metastasis.

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Zheng, Guan-Yu. "Numerical Investigation of Characteristic of Anisotropic Thermal Conductivity of Natural Fiber Bundle with Numbered Lumens". Mathematical Problems in Engineering 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/506818.

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Natural fiber bundle like hemp fiber bundle usually includes many small lumens embedded in solid region; thus, it can present lower thermal conduction than that of conventional fibers. In the paper, characteristic of anisotropic transverse thermal conductivity of unidirectional natural hemp fiber bundle was numerically studied to determine the dependence of overall thermal property of the fiber bundle on that of the solid region phase. In order to efficiently predict its thermal property, the fiber bundle was embedded into an imaginary matrix to form a unit composite cell consisting of the matrix and the fiber bundle. Equally, another unit composite cell including an equivalent solid fiber was established to present the homogenization of the fiber bundle. Next, finite element thermal analysis implemented by ABAQUS was conducted in the two established composite cells by applying proper thermal boundary conditions along the boundary of unit cell, and influences of the solid region phase and the equivalent solid fiber on the composites were investigated, respectively. Subsequently, an optional relationship of thermal conductivities of the natural fiber bundle and the solid region was obtained by curve fitting technique. Finally, numerical results from the obtained fitted curves were compared with the analytic Hasselman-Johnson’s results and others to verify the present numerical model.

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Wei, Jiakai, Wuxiang Zhang e Xilun Ding. "Design and Finite Element Analysis of Artificial Braided Meniscus Model". Materials 16, n. 13 (1 luglio 2023): 4775. http://dx.doi.org/10.3390/ma16134775.

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Currently, artificial meniscus prostheses are mostly homogenous, low strength, and difficult to mimic the distribution of internal fibers in the native meniscus. To promote the overall mechanical performance of meniscus prostheses, this paper designed a new artificial braided meniscus model and conducted finite element analysis. Firstly, we designed the spatial fiber interweaving structure of meniscus model to mimic the internal fiber distribution of the native meniscus. Secondly, we provided the detailed braiding steps and forming process principles based on the weaving structure. Thirdly, we adopted the models of the fiber-embedded matrix and multi-scale methods separately for finite element analysis to achieve the reliable elastic properties. Meanwhile, we compared the results for two models, which are basically consistent, and verified the accuracy of analysis. Finally, we conducted the comparative simulation analysis of the meniscus model and the pure matrix meniscus model based on the solved elastic constants through Abaqus, which indicated a 60% increase in strength.

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Zhang, Yunqian, Lilong Luo, Guofan Zhang, Liang Chang e Xiaohua Nie. "Tension Performance Prediction and Experiment of Optical Smart Composites Using Micromechanical Failure Theory". Journal of Physics: Conference Series 2891, n. 13 (1 dicembre 2024): 132013. https://doi.org/10.1088/1742-6596/2891/13/132013.

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Abstract Embedding fiber optic sensors in composites can long-term instantly monitor the deformation and damage within the composite structure, which realizes structural health monitoring and life prediction. However, fiber embedding generally brings damage in terms of the composite material integrity and continuity, resulting the extreme stress concentration in the interface of the optical fiber and composite. Therefore, the mechanical properties of the composite material are potentially influenced unfavorably. To investigate the influence of microstructures such as optical fibers on the macroscopic tensile mechanical properties of composites, this paper develops a progressive damage analysis model inspired by the micromechanical failure theory. The established model can predict the stiffness and strength properties of fiber smart composites. The model is further verified by comparing the obtained tensile failure mechanism with the experimental results. The results show that the maximum relative error of the destructive load is only 3%, which demonstrates the accuracy and validity of the model. The work of this paper can provide guides for the optimization and strength prediction of smart composite structures with embedded optical fibers.

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Huzni, Syifaul, Ikramullah Ikramullah, Israr B. M. Ibrahim, Syarizal Fonna, Teuku Arriessa Sukhairi, Andri Afrizal, Umar Muksin, Abdul Khalil H. P. S., Sri Aprilia e Samsul Rizal. "The Role of Typha angustifilia Fiber–Matrix Bonding Parameters on Interfacial Shear Strength Analysis". Polymers 14, n. 5 (2 marzo 2022): 1006. http://dx.doi.org/10.3390/polym14051006.

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The microbond test of natural fibers tends to produce scattered interfacial shear stress (IFSS) values. The sources of this scattering are known, but the roles they play in producing high IFSS scattering remain to be investigated. In this study, a numerical method was used to simulate microbond testing and to examine the experimental parameters in a microbond test of Typha angustifolia fiber/epoxy. Three parameters were considered: fiber diameter, fiber length embedded in the epoxy, and the distance between the vise and the specimen. The geometries were modeled and analyzed by ABAQUS software using its cohesive zone model features. There were two types of contact used in this analysis: tie constraint and surface-to-surface. The results showcased the roles of the following experimental parameters: a larger fiber diameter from a sample increased the IFSS value, a longer embedded length reduced the IFSS value, and a shorter vise–specimen distance increased the IFSS value. The IFSS scattering in the microbond test could have originated from the interaction between these parameters. Of the three parameters, only the vise–specimen distance was found to be able to be reasonably controlled. When the IFSS value was atypically large, fiber diameter and/or embedded length potentially drove the scattering. This study advises further compilation and classification of the role of each experimental parameter in modulating the IFSS value.

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Zhu, Da Sheng, e Bo Qin Gu. "Micromechanical Analysis of Single-Fiber Pull-Out Test of Fiber-Reinforced Viscoelastic Matrix Composites". Advanced Materials Research 399-401 (novembre 2011): 556–60. http://dx.doi.org/10.4028/www.scientific.net/amr.399-401.556.

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A micromechanical model for single-fiber pull-out test of fiber-reinforced viscoelastic matrix composites is established. It includes fiber, interphase and viscoelastic matrix. The formulas to calculate the fiber axial stress, the interphase shear stress, and the matrix axial and shear stress are obtained. Moreover, for Kevlar aramid fiber reinforced viscoelastic matrix composites, the influences of the interphase thickness, the fiber embedded length and volume fraction on the stress distributions of fiber and interphase is studied. Some analysis results show that, with the increase of normalized fiber axial distance, the fiber axial stress increases monotonically, but the interphase shear stress decreases. The stress distributions of fiber and interphase change with the variation of the interphase thickness, the fiber embedded length and volume fraction.

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30

Fedotov, M. Yu. "THEORETICAL RESEARCHES OF THE EMBEDDED FIBER-OPTIC SYSTEM OF TESTING DEFORMATION AND TEMPERATURE OF POLYMER COMPOSITES". Kontrol'. Diagnostika, n. 299 (maggio 2023): 14–25. http://dx.doi.org/10.14489/td.2023.05.pp.014-025.

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This article describes the results of theoretical researches of the system of optical testing of polymer composites by the method of two optical fibers with different sensitivity to deformation and temperature, using integrated arrays of fiber Bragg gratings. The features of the primary data processing from the optical testing system embedded into the composite are considered by the methods of weighted arithmetic mean and approximation by the Gaussian function. The basic relations for calculating the error in determining the temperature and strain with the help of fiber-optic embedded testing systems are obtained. A numerical model of the interrogator has been constructed, which makes it possible to estimate the systematic error of deformation and temperature measurements, including taking into account the noise of a real interrogator. It is shown that, taking into account a number of assumptions for the problem of simultaneous embedded testing of composites with fiber Bragg gratings, it is advisable to apply he method of primary processing of testing data using the approximation of the real spectra of fiber Bragg gratings by the Gaussian function, while in order to increase the reliability of testing, it is necessary to take into account the temperature correction characteristic of a particular interrogating device.

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31

Chanda, Arnab, Subhodip Chatterjee e Vivek Gupta. "Soft composite based hyperelastic model for anisotropic tissue characterization". Journal of Composite Materials 54, n. 28 (23 giugno 2020): 4525–34. http://dx.doi.org/10.1177/0021998320935560.

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Abstract (sommario):

Soft tissues are complex anisotropic composite systems comprising of multiple differently oriented layers of fiber embedded within a soft matrix. To date, soft tissues have been mainly characterized using simplified linear elastic material models, isotropic viscoelastic and hyperelastic models, and transversely isotropic models. In such models, the effect of fiber volume fraction (FVF), fiber orientation, and fiber-matrix interactions are missing, inhibiting accurate characterization of anisotropic tissue properties. The current work addresses this literature gap with the development of a novel soft composite based material framework to model tissue anisotropy. In this model, the fiber and matrix are considered as separate hyperelastic materials, and fiber-matrix interaction is modeled using multiplicative decomposition of the deformation gradient. The effect of the individual contribution of the fibers and matrix are introduced into the numerical framework for a single soft composite layer, and fiber orientation effects are incorporated into the strain energy functions. Also, strain energy formulations are developed for multiple soft composite layers with varying fiber orientations and contributions, describing the biomechanical behavior of an entire anisotropic tissue block. Stress-strain relationships were derived from the strain energy equations for a uniaxial mechanical test condition. To validate the model parameters, experimental models of soft composites tested under uniaxial tension were characterized using the novel anisotropic hyperelastic model (R2 = 0.983). To date, such a robust anisotropic hyperelastic composite framework has not been developed, which would be indispensable for experimental characterization of tissues and for improving the fidelity of computational biological models in future.

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Selvadurai, A. P. S., e A. ten Busschen. "Mechanics of the Segmentation of an Embedded Fiber, Part II: Computational Modeling and Comparisons". Journal of Applied Mechanics 62, n. 1 (1 marzo 1995): 98–107. http://dx.doi.org/10.1115/1.2895889.

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Abstract (sommario):

A fragmentation test has been developed for the study of the influence of the adhesive characteristics of the interface between reinforcing fibers and the matrix on the development of matrix cracking at a cracked single fiber location. The present paper examines the numerical modeling of the crack extension process within the matrix region. The numerical modeling focuses on the application of boundary element techniques to the study of an axisymmetric fiber-matrix model and quasi-static crack extension criteria are employed to determine the path of crack extension. The result for the crack extension patterns obtained from the numerical models are compared with the results derived from the experiments. It is shown that elastic fracture mechanics simulations of quasi-static crack extension can successfully model the observed experimental phenomena.

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Wu, Jing, e Ai Qin Xu. "A Resistance Model of Carbon Fiber Composite Materials Based on Interfacial Effect". Applied Mechanics and Materials 496-500 (gennaio 2014): 2379–82. http://dx.doi.org/10.4028/www.scientific.net/amm.496-500.2379.

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Abstract (sommario):

Based on the single fiber pull-out testing, the resistance of carbon fiber cement increases during the tensile test in elastic stage. Through the experiment, The fiber embedded length shorter, sample pullout strength is greater. But the resistance change rate is smaller, the lower the sensitivity of the sample. So, considering the fiber length and interface set interface effect of carbon fiber reinforced cement based composite resistance model. A simple model was proposed to explain the mechanism of compression sensitivity of carbon fiber reinforced cement-based composites based on interface effect. The results showed that the content of carbon fiber and interface strain can change the sensitivity of CFRC.

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Childers, Carey F. "Mathematical Model of the Effective Properties of a Fiber Reinforced Composite with a Linearly Graded Transition Zone". Tire Science and Technology 38, n. 4 (1 dicembre 2010): 286–307. http://dx.doi.org/10.2346/1.3519536.

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Abstract (sommario):

Abstract Tires are fabricated using single ply fiber reinforced composite materials, which consist of a set of aligned stiff fibers of steel material embedded in a softer matrix of rubber material. The main goal is to develop a mathematical model to determine the local stress and strain fields for this isotropic fiber and matrix separated by a linearly graded transition zone. This model will then yield expressions for the internal stress and strain fields surrounding a single fiber. The fields will be obtained when radial, axial, and shear loads are applied. The composite is then homogenized to determine its effective mechanical properties—elastic moduli, Poisson ratios, and shear moduli. The model allows for analysis of how composites interact in order to design composites which gain full advantage of their properties.

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Bondarev, B. A., N. N. Chernousov, R. N. Chernousov e V. A. Sturova. "EXPERIMENTAL STUDY OF THE NATURE OF INTERACTION OF STEEL FIBRES EQUIDIRECTIONALLY LOCATED IN PARALLEL TO FORCE IN FINE-GRAINED SLAG CONCRETE". Proceedings of the Southwest State University 21, n. 2 (28 aprile 2017): 72–82. http://dx.doi.org/10.21869/2223-1560-2017-21-2-72-82.

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Abstract (sommario):

At present, the use of modern technologies is becoming more urgent. This concerns both construction engineering and structural design standards. There is a need for a wider use of computer technology, which will allow solving multifactorial tasks taking into account actual stress-strain state of structures at all the stages of their operation with the help of a nonlinear deformation model in the future. The objective of this work is to study the nature of the interaction of steel fibers equidirectionally located in parallel to force in fine-grained slag concrete, in particular, to determine the coefficient characterizing the change in the contribution to the work of the fibre reinforcement unit depending on the length of the adjacent fibers embedment in the slag concrete and the quality of adhesion between them, and construction of a graphical model of steel fibers operation in cinderblock matrix, diagrams of deformation (state) of concrete, reinforcement and fiberы which are an integral characteristic of physical and mechanical properties of materials. Tests for the extraction of steel fibers with single offset bends at the ends of fine-grained slag concrete have been carried out. Experimental dependences of steel fibers displacement on the applied load have been obtained. Based on the results of the experimental data analysis, formulas for determining the coordinates of piecewise-linear ‘load-displacement’ diagrams are proposed; they describe the displacement of a single fiber from fine-grained slag-concrete, which allows drawing conclusions concerning their mutual influence on the anchoring ability in fine-grained slag concrete. Dependencies for determining the coefficient characterizing the change in the contribution to the work of the fibre reinforcement unit depending on the length of the adjacent fibers embedment in the slag concrete and the quality of adhesion between these fibers and the slag concrete-matrix are proposed. The work also presents common dependencies, which can be used to construct analytical piece-wise diagrams ‘load-displacement’ and describe the work of fiber embedded in fine-grained slag concrete when calculating the units of building structures from steel-fiber-slag-concrete by means of a computer using the diagram technique.

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Qiao, Yan, Chuan Zhi Sun e Biao Zhang. "Research on Strain Transfer of Embedded BOTDA Sensors Analyzed by FEM". Applied Mechanics and Materials 357-360 (agosto 2013): 1473–79. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.1473.

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in this paper, the theory of strain transfer of embedded BOTDA sensors was introduced. For the sensing fiber with coating and jacket used in project, its finite element model was built by ANSYS infinite element analysis software. And for the embedded fiber, the influences affected by elastic modulus and thickness of the fiber coating and jacket and elastic modulus of matrix material were analyzed. For the surface bonded fiber, the influences affected by elastic modulus, width and thickness of the bonding material were analyzed, and the results were compared with the results of theory.

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Herranen, Hendrik, Jaan Kers, Jürgo S. Preden, Robert Talalaev, Martin Eerme, Jüri Majak, Henri Lend e Georg Allikas. "Embedded Electronics Influence on the Strength of Carbon Fiber Laminate". Advanced Materials Research 905 (aprile 2014): 239–43. http://dx.doi.org/10.4028/www.scientific.net/amr.905.239.

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A complex electronics circuit placeholder is embedded in the carbon fiber laminate. The reduction of the material mechanical strength is assessed. The strain interaction between electronics and carbon fiber laminate is measured with digital image correlation based deformation scanner GOM ARAMIS 2M. A finite element analysis model is developed and validated. Based on FEA results the response model for prediction of the mechanical properties of laminate is introduced.

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Tur, Bogac, Lucia Gühring, Olaf Wendler e Stefan Kniesburges. "Influence of airflow and ligament tension on the acoustics of a biomimetic larynx model". Journal of the Acoustical Society of America 155, n. 3_Supplement (1 marzo 2024): A340. http://dx.doi.org/10.1121/10.0027748.

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The phonation process is a complex interaction involving the airflow from the lungs, the oscillation of the vocal folds’ tissue, and the resultant acoustics. To understand the underlying physical mechanisms, an experimental model has been designed that allow the control of flowrate and longitudinal tension of the vocal folds. A synthetic biomimetic larynx model was applied that features airflow-driven vocal folds’ oscillations. The longitudinal stiffness of the vocal folds is controlled using embedded ligament fibers. The model enables to measure aerodynamic and acoustic signals as function of airflow rate and the fiber tension. Based on the measured signals, the influence of airflow and fiber tension was statistically analyzed using the parameters F0, Psub, CPP, HNR, Shimmer, and Jitter. The statistical analysis revealed that both flowrate and fiber tension significantly influence acoustic and aerodynamic parameters. In general, the parameters showed different trends for increasing flowrate and fiber tension. Increase in fiber tension produced increasing parameters up to a maximum tension level followed by a saturation of the parameters. In contrast, the flowrate showed varying trends depending on the respective parameter. The results clearly show how flowrate and longitudinal tension control the phonation process and the resulting acoustic quality.

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Murgo, Francesco Saverio, Francesca Ferretti e Claudio Mazzotti. "A discrete-cracking numerical model for the in-plane behavior of FRCM strengthened masonry panels". Bulletin of Earthquake Engineering 19, n. 11 (28 maggio 2021): 4471–502. http://dx.doi.org/10.1007/s10518-021-01129-6.

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AbstractIn this paper, the structural behavior of masonry panels strengthened with a system made up of composite fiber grids embedded in a cementitious matrix (FRCM) is presented. The non-linear behavior of the unreinforced and reinforced panels is numerically simulated by means of a simplified micro-modelling approach. This approach concentrates all the non-linearities and failures in the joints and in potential crack surfaces within the bricks, placed vertically in the middle of each brick. The FRCM strengthening system is discretized by a continuous bi-directional fiber grid constituted by trusses embedded into a cementitious matrix. A calibrated bond-slip relationship is applied between the fibers and the mortar matrix assuming an idealized bilinear law. The typical experimental load–displacement curve for a FRCM strengthened panel shows three principal phases that correspond to different failure mechanisms: masonry cracking, mortar matrix cracking and ultimate failure of the panel. The non-linear numerical analyses show a good agreement with experimental results and the modeling approach is found to be adequate to reproduce the described experimental behavior. The results of a parametric study on both the material and the geometrical properties of the FRCM system are also presented.

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Chen, Bin, Da Gang Yin, Quan Yuan, Ji Luo e Jing Hong Fan. "Microstructural Model of Enveloping-Core Fiber Distribution of Conifer Wood and Research on Biomimetic Wood Composite". Materials Science Forum 686 (giugno 2011): 406–10. http://dx.doi.org/10.4028/www.scientific.net/msf.686.406.

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Abstract (sommario):

The observation on conifer wood shows that wood is a kind of biocomposite consisting of wood fibers and lignin matrix. The wood fibers are embedded in the lignin matrix with parallel distribution. It is also observed that the wood fibers continuously envelop the columned branch cores in the wood forming a kind of enveloping-core fiber distribution (ECFD). The ultimate load of the composite model with the ECFD is investigated and compared with that of the composite model with non-enveloping-core fiber distribution (NECFD). It shows that the strength of the composite model with the ECFD is larger than that of the composite model with NECFD. A kind of mimetic-wood composite specimens with the ECFD is also fabricated. The test was carried out with ECFD specimens and compared with that of the composite specimens with the NECFD. The result show that the ultimate strength of the former is significantly larger than that of the latter.

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Kumar, R. Krishna, e J. N. Reddy. "Stress Distributions During Fiber Pull-Out". Journal of Applied Mechanics 63, n. 2 (1 giugno 1996): 301–6. http://dx.doi.org/10.1115/1.2788864.

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Abstract (sommario):

Fiber pull-out resistance is an important mechanism of energy absorption during the failure of fiber-reinforced composite materials. This paper deals with axial stress distribution in the fiber during a pull-out. The frictional constraint between the fiber and the matrix is modeled with a perturbed Lagrangian approach and Coulomb’s law of friction. Stress distribution has been determined for three cases, using the finite element method. The first case deals with the pull out of a fully embedded fiber. The second determines the stress distribution during fiber pull-out in the presence of a broken-embedded fiber. The third model attempts to solve the pull out of a coated fiber. The results for the first case compares favorably with those in existing literature. A local “pinching” effect, due to the matrix collapse behind the pulled fiber, is brought out clearly by this model. The second study indicates that the “plug” effect may not be significant in affecting the stress distribution. Lastly, the effects of coating stiffness and thickness are investigated.

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Chanda, Arnab, e Christian Callaway. "Tissue Anisotropy Modeling Using Soft Composite Materials". Applied Bionics and Biomechanics 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/4838157.

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Abstract (sommario):

Soft tissues in general exhibit anisotropic mechanical behavior, which varies in three dimensions based on the location of the tissue in the body. In the past, there have been few attempts to numerically model tissue anisotropy using composite-based formulations (involving fibers embedded within a matrix material). However, so far, tissue anisotropy has not been modeled experimentally. In the current work, novel elastomer-based soft composite materials were developed in the form of experimental test coupons, to model the macroscopic anisotropy in tissue mechanical properties. A soft elastomer matrix was fabricated, and fibers made of a stiffer elastomer material were embedded within the matrix material to generate the test coupons. The coupons were tested on a mechanical testing machine, and the resulting stress-versus-stretch responses were studied. The fiber volume fraction (FVF), fiber spacing, and orientations were varied to estimate the changes in the mechanical responses. The mechanical behavior of the soft composites was characterized using hyperelastic material models such as Mooney-Rivlin’s, Humphrey’s, and Veronda-Westmann’s model and also compared with the anisotropic mechanical behavior of the human skin, pelvic tissues, and brain tissues. This work lays the foundation for the experimental modelling of tissue anisotropy, which combined with microscopic studies on tissues can lead to refinements in the simulation of localized fiber distribution and orientations, and enable the development of biofidelic anisotropic tissue phantom materials for various tissue engineering and testing applications.

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Lebel-Cormier, Marie-Anne, Tommy Boilard, Martin Bernier e Luc Beaulieu. "Medical Range Radiation Dosimeter Based on Polymer-Embedded Fiber Bragg Gratings". Sensors 21, n. 23 (6 dicembre 2021): 8139. http://dx.doi.org/10.3390/s21238139.

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Abstract (sommario):

Fiber Bragg gratings (FBGs) are valuable dosimeters for doses up to 100 kilograys (kGy), but have hardly been used for the low-dose range of a few grays (Gy) required in medical radiation dosimetry. We report that embedding a doped silica fiber FBG in a polymer material allows a minimum detectable dose of 0.3 Gy for γ-radiation. Comparing the detector response for different doped silica fibers with various core doping, we obtain an independent response, in opposition to what is reported for high-dose range. We hypothesized that the sensor detection is based on the radio-induced thermal expansion of the surrounding polymer. Hence, we used a simple physical model based on the thermal and mechanical properties of the surrounding polymer and obtained good accordance between measured and calculated values for different compositions and thicknesses. We report that over the 4 embedding polymers tested, polyether ether ketone and polypropylene have respectively the lowest (0.056 pm/Gy) and largest sensitivity (0.087 pm/Gy). Such FBG-based dosimeters have the potential to be distributed along the fiber to allow multipoint detection while having a sub-millimeter size that could prove very useful for low-dose applications, in particular for radiotherapy dosimetry.

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Hsueh, C. H., R. J. Young, X. Yang e P. F. Becher. "Stress transfer in a model composite containing a single embedded fiber". Acta Materialia 45, n. 4 (aprile 1997): 1469–76. http://dx.doi.org/10.1016/s1359-6454(96)00262-5.

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Sirkis, James S., e Henry W. Haslach. "Complete Phase-Strain Model for Structurally Embedded Interferometric Optical Fiber Sensors". Journal of Intelligent Material Systems and Structures 2, n. 1 (gennaio 1991): 3–24. http://dx.doi.org/10.1177/1045389x9100200101.

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46

Xie, Xinyu, Jiantao Bai e Wenjie Zuo. "Topology optimization of fiber-reinforced concrete structures using membrane-embedded model". Engineering Structures 314 (settembre 2024): 118299. http://dx.doi.org/10.1016/j.engstruct.2024.118299.

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Zhang, Xuan, Hong Lei Jiang e Xiao Bing Man. "Preparation of Catalytic Paper Using Fe-Pillared Bentonite as Filler by a Paper-Making Technique". Advanced Materials Research 955-959 (giugno 2014): 127–30. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.127.

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Abstract (sommario):

Fe-pillared bentonite was made into a paper-like composite by a papermaking technique using pulp fiber and activated carbon fiber. Orange II was used as a model compound to investigate the photocatalytic performance of the paper. SEM analysis showed that the catalytic paper had a porous structure originating from the layered fiber network, with Fe-pillared bentonite mostly embedded in the grooves along the axial direction of the carbon fibers. The optimum preparation conditions were: activated carbon fiber:Fe-pillared bentonite=1:2, activated carbon fiber:pulp fiber=5:3, the charges of Na2SiO3 and PAE were 2.5% based on the Fe-pillared bentonite and 0.4% based on the oven-dry fibers, respectively. The degradation ratio reached 85.2% at 180 min and after that little increase was observed. The catalyst could be repeatedly use and keep a high stability during the first 4 cycling use.

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Cusano, A., P. Capoluongo, S. Campopiano, A. Cutolo, M. Giordano, F. Felli, A. Paolozzi e M. Caponero. "Experimental modal analysis of an aircraft model wing by embedded fiber Bragg grating sensors". IEEE Sensors Journal 6, n. 1 (febbraio 2006): 67–77. http://dx.doi.org/10.1109/jsen.2005.854152.

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Yi, Duo. "Development of a flame spraying coating–based fiber composite structure: A thermo-mechanical finite element study". Journal of Intelligent Material Systems and Structures 31, n. 16 (21 luglio 2020): 1950–58. http://dx.doi.org/10.1177/1045389x20942324.

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Abstract (sommario):

The optical fiber smart composite structures have been widely applied for the structural health monitoring, and the packaging technique of integrating optical fiber sensor with host structure is one of the key issues. The flame spraying coating provides strong adhesive strength with good heat resistance, which is particularly suitable for the packaging applications in harsh environments. However, the elaboration process of flame spraying coating–based fiber composite structure faces great challenges due to the flame spraying mechanisms. This study evaluates numerically an overall effect of flame spraying coating formation process on the structural and the optical properties of the embedded fiber optic based on a three-dimensional finite element model. First, the lumped capacitance method is used; both the average heat flux density in the whole spraying process and the specific heat flux density of each torch sweep are estimated to initialize the thermo-mechanical modeling. Then, the stress distributions in both radial and axial directions of the embedded fiber are discussed separately. Next, the variation of refractive index of the embedded fiber optic due to the residual strain is also investigated. Finally, the elaboration parameters including torch displacement and velocity are evaluated and optimized. The simulation results show that the embedded fiber optic maintains good structural and optical properties with the presented elaboration conditions, and therefore its transmission and sensing performance can be ensured.

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Sunny, John, Hadi Nazaripoor, Jorge Palacios Moreno e Pierre Mertiny. "Accelerated Zero-Stress Hydrothermal Aging of Dry E-Glass Fibers and Service Life Prediction Using Arrhenius Model". Fibers 11, n. 8 (15 agosto 2023): 70. http://dx.doi.org/10.3390/fib11080070.

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Comprehending the degradation of glass fibers is crucial for service applications involving dry and wet conditions, especially when prolonged contact with water above room temperature is present. Depending on the polymer material, both thermosetting and thermoplastic matrices can permit the ingress of moisture. Therefore, fiber reinforcements embedded in the polymer matrix may experience moisture exposure. Additionally, some structural applications use fiber devoid of any matrix (dry fibers), in which water exposure must be avoided. In all of these cases, moisture may, therefore, have a significant impact on the reinforcing elements and the rate of degradation. The present work focuses on the effects of hydrothermal aging on the mechanical durability of long E-glass fibers by immersion in water at 60 °C, 71 °C, and 82 °C. A service life forecast model was created utilizing the Arrhenius technique, and a master curve of strength variation with exposure time was created for E-glass fibers at 60 °C. Using this modeling approach, it is possible to approximate the amount of time it will take to attain a given degradation level over a specified range of temperatures. Scanning electron microscopy was used to evaluate morphological changes in fiber surfaces due to hydrothermal exposure, while Fourier transform infrared spectroscopy and mass dissolution studies were used to elucidate the mechanism of the strength loss.

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