FIBER REINFORCED ASPHALT

2021 ◽  
Author(s):  
RYAN COY ◽  
RAFAEL GOMEZ CONSARNAU ◽  
IAN HOLMES ◽  
DANIEL WHISLER
Keyword(s):  
Particulate Composite ◽  
Material Behavior ◽  
Material System ◽  
Short Fibers ◽  
Extended Finite Element ◽  
Element Analysis ◽  
Unique Material ◽  
Milling Machines ◽  
The Matrix ◽  
Heavy Loads

Asphalt can be considered a particulate composite with almost no tensile strength, that is, the only physical link between the matrix (bitumen) and the particles (gravel) is the cohesive strength of the bond itself and the aggregate simply breaks away from the binder under any number of tension-based loads such as earth shifts, heavy loads, and even moisture. Over the course of a few months, these breaks lead to larger cracks, potholes, and damaged entire road sections that require significant investment much earlier than the expected 15-year lifecycle. Increasing the strength and modulus of asphalt can improve its durability, extend its lifespan, and reduce its maintenance costs. However, as most asphalt is usually recycled during rehabilitation, improving strength cannot come at the expense of the existing infrastructure support system, i.e., materials and technologies should be compatible with road resurfacing equipment and practices. Short composite fibers have high modulus and strength but are easily broken up by road milling machines, making them ideal candidates to mix into the asphalt during rehabilitation. Additionally, by deliberately limiting the fiber size, this will have a major ancillary benefit for the environment: allowing the use of off-fall composite scraps from the manufacturing sectors that are often chopped and relegated to landfills. This investigation examines the material behavior from both experimental and numerical perspective on the inclusion of short fibers for reinforcing asphalt, creating a dual fiber and particle composite material system. Asphalt by its very nature is a relatively soft material with high strains until failure under some conditions, and brittle under others, making this a complex material system combining both hyperelastic and elastic-brittle response. Validation studies are examined for this unique material under various quasi-static to dynamic loading rates to create a material system for extended finite element analysis in improved infrastructure designs.

Particulate Composite Damage: Numerical Estimation of Micro-Crack Propagation Direction

2013 ◽  
Vol 592-593 ◽  
pp. 445-448 ◽  
Author(s):  
Zdeněk Majer ◽  
Petr Marcián ◽  
Luboš Náhlík ◽  
Pavel Hutař ◽  
Zdeněk Knésl
Keyword(s):  
Crack Propagation ◽  
High Performance ◽  
Construction Materials ◽  
Particulate Composite ◽  
Polymer Particle ◽  
Propagation Direction ◽  
Material Behavior ◽  
Rigid Particles ◽  
Crack Propagation Direction ◽  
The Matrix

In recent years, particle reinforced composites are widely used due their mechanical properties as construction materials, high-performance engineering materials or protective organic coatings. The paper was mainly focused on the estimating of the interactions of the micro-crack and the particles in the particulate polymer composites. A non-linear material behavior of the matrix was obtained from the experiment and it was used to investigation by means of the finite element method - using ANSYS software. A two-dimensional numerical model was developed and a micro-crack propagation direction was calculated based on the assumption of the linear elastic fracture mechanics. The results indicated that the presence of the interphase between particle and matrix can improve the fracture toughness of the polymer particle composites through debonding process. The paper can contribute to a better understanding of the behavior and failure of the composites with the polymer matrix reinforced by the rigid particles.

Micro-Crack Propagation in Particulate Composite with Different Types of Matrix

2012 ◽  
Vol 245 ◽  
pp. 138-143 ◽  
Author(s):  
Zdeněk Majer ◽  
Luboš Náhlík
Keyword(s):  
Polymer Matrix ◽  
High Performance ◽  
Construction Materials ◽  
Particulate Composite ◽  
Polymer Particle ◽  
Material Behavior ◽  
Particulate Composites ◽  
Mineral Filler ◽  
Non Linear ◽  
The Matrix

Particulate composites with polymer matrix and solid fillers are one of important types of materials. Generally, these materials are usually used as construction materials, high-performance engineering materials or protective organic coatings. The main aim of a present paper is an estimation of the micro-crack behavior in the particulate composite with non-linear polymer matrix. The polymer matrix filled by magnesia-based mineral filler is investigated by means of the finite element method. A non-linear material behavior of the matrix was obtained from experiment as well as properties of mineral filler. Numerical model on the base of representative plane element (RPE) was developed. The results show that the presence of interphase between particle and matrix can improve fracture toughness of polymer particle composite through debonding process. The conclusions of this paper can contribute to a better understanding of the behavior of micro-crack in particulate composites with respect to interphase.

Load Influence on the Behavior of Micro-Crack in the Particulate Composite

2012 ◽  
Vol 525-526 ◽  
pp. 173-176 ◽  
Author(s):  
Zdeněk Majer
Keyword(s):  
Polymer Matrix ◽  
Particulate Composite ◽  
Material Behavior ◽  
Particulate Composites ◽  
Soft Matrix ◽  
Close Proximity ◽  
Plane Element ◽  
The Matrix ◽  
Soft Polymer ◽  
Mineral Fillers

Particulate composite with soft polymer matrix and rigid mineral fillers are one of most frequently used construction and engineering materials. The main focus of a present paper is an estimation of the load influence on behavior of micro-crack placed in close proximity to the particle with interphase in soft matrix. The particulate composite with polymer matrix filled by magnesium-based mineral fillers is investigated by means of the finite element method. A non-linear material behavior of the matrix was considered. Numerical model on the base of representative plane element (RPE) was developed. The conclusions of this paper can contribute to a better understanding of the behavior of micro-crack in particulate composites with soft polymer matrix.

scholarly journals Impact of residual stress evoked by pyramidal embossing on the magnetic material properties of non-oriented electrical steel

2021 ◽  
Author(s):  
Ines Gilch ◽  
Tobias Neuwirth ◽  
Benedikt Schauerte ◽  
Nora Leuning ◽  
Simon Sebold ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Residual Stress ◽  
Magnetic Flux ◽  
Material Properties ◽  
Electrical Steel ◽  
Maximum Energy ◽  
Material Behavior ◽  
Electrical Machine ◽  
Element Analysis ◽  
Steel Sheets

AbstractTargeted magnetic flux guidance in the rotor cross section of rotational electrical machines is crucial for the machine’s efficiency. Cutouts in the electrical steel sheets are integrated in the rotor sheets for magnetic flux guidance. These cutouts create thin structures in the rotor sheets which limit the maximum achievable rotational speed under centrifugal forces and the maximum energy density of the rotating electrical machine. In this paper, embossing-induced residual stress, employing the magneto-mechanical Villari effect, is studied as an innovative and alternative flux barrier design with negligible mechanical material deterioration. The overall objective is to replace cutouts by embossings, increasing the mechanical strength of the rotor. The identification of suitable embossing geometries, distributions and methodologies for the local introduction of residual stress is a major challenge. This paper examines finely distributed pyramidal embossings and their effect on the magnetic material behavior. The study is based on simulation and measurements of specimen with a single line of twenty embossing points performed with different punch forces. The magnetic material behavior is analyzed using neutron grating interferometry and a single sheet tester. Numerical examinations using finite element analysis and microhardness measurements provide a more detailed understanding of the interaction of residual stress distribution and magnetic material properties. The results reveal that residual stress induced by embossing affects magnetic material properties. Process parameters can be applied to adjust the magnetic material deterioration and the effect of magnetic flux guidance.

scholarly journals Assessing the Flexural Properties of Epoxy Composites with Extremely Low Addition of Cellulose Nanofiber Content

2020 ◽  
Vol 10 (3) ◽  
pp. 1159 ◽  
Author(s):  
Yingmei Xie ◽  
Hiroki Kurita ◽  
Ryugo Ishigami ◽  
Fumio Narita
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Flexural Modulus ◽  
Strengthening Mechanism ◽  
Short Fiber ◽  
Cellulose Nanofiber ◽  
Resin Matrix ◽  
Element Analysis ◽  
Epoxy Resin Matrix ◽  
The Matrix

Epoxy resins are a widely used common polymer due to their excellent mechanical properties. On the other hand, cellulose nanofiber (CNF) is one of the new generation of fibers, and recent test results show that CNF reinforced polymers have high mechanical properties. It has also been reported that an extremely low CNF addition increases the mechanical properties of the matrix resin. In this study, we prepared extremely-low CNF (~1 wt.%) reinforced epoxy resin matrix (epoxy-CNF) composites, and tried to understand the strengthening mechanism of the epoxy-CNF composite through the three-point flexural test, finite element analysis (FEA), and discussion based on organic chemistry. The flexural modulus and strength were significantly increased by the extremely low CNF addition (less than 0.2 wt.%), although the theories for short-fiber-reinforced composites cannot explain the strengthening mechanism of the epoxy-CNF composite. Hence, we propose the possibility that CNF behaves as an auxiliary agent to enhance the structure of the epoxy molecule, and not as a reinforcing fiber in the epoxy resin matrix.

Localized Necking in a Round Tensile Bar with HCP Material Considering Tension-Compression Asymmetry in Plastic Flow

2013 ◽  
Vol 535-536 ◽  
pp. 164-167
Author(s):  
Jonghun Yoon ◽  
Oana Cazacu ◽  
Jung Hwan Lee
Keyword(s):  
Yield Criterion ◽  
Matrix Material ◽  
Ductile Failure ◽  
Material Behavior ◽  
Strength Differential ◽  
The Matrix ◽  
Void Evolution ◽  
Hcp Materials ◽  
Spherical Voids ◽  
Tension Compression Asymmetry

In spite of this progress in predicting ductile failure, the development of macroscopic yield criteria for describing damage evolution in HCP (hexagonal close-packed) materials remains a challenge. HCP materials display strength differential effects (i.e., different behavior in tension versus compression) in the plastic response due to twinning. Cazacu and Stewart [1] developed an analytic yield criterion for a porous material containing randomly distributed spherical voids in an isotropic, incompressible matrix that displays tension-compression asymmetry. The matrix material was taken to obey the isotropic form of the Cazacu et al. [2] yield criterion, which captures the tension-compression asymmetry of the matrix material. In this paper, finite element calculations of a round tensile bar are conducted with the material behavior described by the Cazacu and Stewart [1] yield criterion. The goal of these calculations is to investigate the effect of the tension-compression asymmetry on the necking induced by void evolution and propagation.

scholarly journals Simulation of thermal cycle aging process on fiber-reinforced polymers by extended finite element method

2017 ◽  
Vol 52 (14) ◽  
pp. 1947-1958 ◽  
Author(s):  
Sergio González ◽  
Gianluca Laera ◽  
Sotiris Koussios ◽  
Jaime Domínguez ◽  
Fernando A Lasagni
Keyword(s):  
Finite Element ◽  
Degradation Process ◽  
Damage Mechanism ◽  
Fiber Reinforced Polymers ◽  
Model Parameters ◽  
Suitable Model ◽  
Fiber Reinforced ◽  
Aging Effects ◽  
Extended Finite Element ◽  
Element Analysis

The simulation of long life behavior and environmental aging effects on composite materials are subjects of investigation for future aerospace applications (i.e. supersonic commercial aircrafts). Temperature variation in addition to matrix oxidation involves material degradation and loss of mechanical properties. Crack initiation and growth is the main damage mechanism. In this paper, an extended finite element analysis is proposed to simulate damage on carbon fiber reinforced polymer as a consequence of thermal fatigue between −50℃ and 150℃ under atmospheres with different oxygen content. The interphase effect on the degradation process is analyzed at a microscale level. Finally, results are correlated with the experimental data in terms of material stiffness and, hence, the most suitable model parameters are selected.

Numerical Modeling of Macroscopic Behavior of Particulate Composite with Crosslinked Polymer Matrix

2011 ◽  
Vol 465 ◽  
pp. 129-132
Author(s):  
Luboš Náhlík ◽  
Bohuslav Máša ◽  
Pavel Hutař
Keyword(s):  
Young’S Modulus ◽  
Polymer Matrix ◽  
Young's Modulus ◽  
Numerical Models ◽  
Strain Curve ◽  
Particulate Composite ◽  
Material Behavior ◽  
Particulate Composites ◽  
Stress Strain ◽  
Crosslinked Polymer

Particulate composites with crosslinked polymer matrix and solid fillers are one of important classes of materials such as construction materials, high-performance engineering materials, sealants, protective organic coatings, dental materials, or solid explosives. The main focus of a present paper is an estimation of the macroscopic Young’s modulus and stress-strain behavior of a particulate composite with polymer matrix. The particulate composite with a crosslinked polymer matrix in a rubbery state filled by an alumina-based mineral filler is investigated by means of the finite element method. A hyperelastic material behavior of the matrix was modeled by the Mooney-Rivlin material model. Numerical models on the base of unit cell were developed. The numerical results obtained were compared with experimental stress-strain curve and value of initial Young’s modulus. The paper can contribute to a better understanding of the behavior and failure of particulate composites with a crosslinked polymer matrix.

DESIGN AND ANALYSIS OF AN INTEGRATED THREE- BAY THERMOPLASTIC COMPOSITE WINGBOX

2021 ◽  
Author(s):  
VINCENZO OLIVERI ◽  
GIOVANNI ZUCCO ◽  
MOHAMMAD ROUHI ◽  
ENZO COSENTINO ◽  
RONAN O’HIGGINS ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Thermoplastic Composite ◽  
High Fidelity ◽  
Material System ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Single Piece ◽  
Load Carrying ◽  
Post Buckling ◽  
Composite Material System

The design of a multi-part aerospace structural component, such as a wingbox, is a challenging process because of the complexity arising from assembly and integration, and their associated limitations and considerations. In this study, a design process of a stiffeners-integrated variable stiffness three-bay wingbox is presented. The wingbox has been designed for a prescribed buckling and post-buckling performance (a prescribed real testing scenario) and made from thermoplastic composite material system (Carbon-PEEK) with the total length of three meters. The stiffeners and spars are integrated into the top and bottom panels of the wingbox resulting a single-piece blended structure with no fasteners or joints. The bottom skin also has an elliptical cut-out for access purposes. The composite tows are steered around this cutout for strain concentration reduction purposes. The fiber/tow steering in the top skin bays (compression side) has also been considered for improved compression-induced buckling load carrying capacity. The proposed design has been virtually verified via high fidelity finite element analysis.

Compressive Deformation of Hollow Microsphere Reinforced Metal Matrix Composites

1994 ◽  
Vol 372 ◽  
Author(s):  
M. T. Kiser ◽  
M. He ◽  
B. Wuj ◽  
F. W. Zok
Keyword(s):  
Aluminum Matrix ◽  
Hollow Microsphere ◽  
Compressive Deformation ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Element Analysis ◽  
Strength Enhancement ◽  
The Matrix ◽  
Matrix Flow ◽  
Measured Strength

AbstractThe compressive deformation characteristics of hollow alumina microsphere reinforced aluminum matrix composites have been studied through both experiments and finite element analysis of unit cell models. Tests have been performed on composites containing around 50 volume percent of microspheres. The effects of the matrix flow stress and microsphere morphology (characterized by the ratio of wall thickness to radius) have been examined. The measured strength enhancement due to the hollow microspheres was found to be considerably less than that predicted by the FEM calculations; a result of microsphere cracking. Experiments have been conducted to document the progression of such damage following casting and mechanical deformation. The potential of this class of composite for impact energy absorption applications is also explored.

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