Dimensional variation and evolution of mechanical properties of wet aged composites reinforced with flax fibers

2020 ◽  
pp. 002199832096604
Author(s):  
Ziad El Hachem ◽  
Amandine Célino ◽  
Georges Challita ◽  
Samuel Branchu ◽  
Antoine Le Duigou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Storage Modulus ◽  
Coupling Agent ◽  
Moisture Absorption ◽  
Matrix Interface ◽  
Flax Fibers ◽  
Dimensional Variation ◽  
Fiber Matrix Interface ◽  
Dynamical Mechanical Properties

The aim of this study is to investigate the dimensional variation of polypropylene composites reinforced with UD flax fibers, and the modification of its dynamical mechanical properties after moisture absorption. The effects of fiber content, coupling agent and moisture content were also examined. Results have shown that the swelling increases significantly when increasing the fiber content and the moisture content. It was also concluded that the addition of a coupling agent reduces the swelling of the composite, by improving the adhesion at the fiber/matrix interface. It is interesting to note that the coefficient of hygroscopic swelling of the composites presents a non-linear evolution, with respect to moisture content. Moreover, it was proved that the addition of fiber and the presence of a coupling agent improve the dynamical mechanical properties of the material. However, following moisture absorption, the storage modulus seems to be decreasing, which might be due to the micro-cracks created as a result of the internal swelling of fibers. Additionally, the coupling agent was found to increase the storage modulus of the composite at dry state, whereas following moisture absorption, it was found that the coupling agent does not modify the storage modulus of the material. Moreover, the results reveal that the dynamic mechanical properties of the composites are hardly dependent on the quality of the material, such as the state of the adhesion at the fiber/matrix interface, a possible misalignment of the fibers within the material and the moisture content within the material at the testing time.

Pore Structure and Mechanical Properties of ZrC/SiC Multi-Components Modified C/C Composites

2013 ◽  
Vol 833 ◽  
pp. 159-164 ◽  
Author(s):  
Xiu Qian Li ◽  
Hai Peng Qiu ◽  
Jian Jiao
Keyword(s):  
Mechanical Properties ◽  
Pore Diameter ◽  
Testing Machine ◽  
Average Pore Diameter ◽  
Flexural Properties ◽  
Matrix Interface ◽  
Polymeric Precursor ◽  
Average Pore ◽  
Fiber Matrix Interface ◽  
Injection Apparatus

The ZrC/SiC multi-components modified C/C composites were prepared by using a hybrid precursor containning polycarbosilane and organic zirconium-contained polymeric precursor as impregnant and C/C composites of low density as preform. The porosity, microstructure and mechanical properties of samples were characterized with mercury injection apparatus, scanning electron microscopy and universal electron testing machine respectively. The results show that the porosity and average pore diameter decrease firstly and increase subsequently with the increase of organic zirconium content of the precursor. When the content of organic zirconium is 50%, the porosity and average pore diameter reach minimum which were7.27% and 0.0795um respectively. The most probabilistic pore diameter shifted from 10-100um to 1-10um at the same time; Meanwhile, the flexural properties also increases and drops immediately as the content of organic zirconium in the precursor adds. When the content of organic zirconium is 25%, the flexural strength reaches maximum of 245.20MPa.The improved flexural properties is attributed to the proper bonding of fiber-matrix interface and the low porosity of samples.

Tensile Properties of Epoxy Composites Reinforced with Continuous Sisal Fibers

2014 ◽  
Vol 775-776 ◽  
pp. 284-289 ◽  
Author(s):  
Sergio Neves Monteiro ◽  
Frederico Muylaert Margem ◽  
Wellington Pereira Inácio ◽  
Artur Camposo Pereira ◽  
Michel Picanço Oliveira
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Epoxy Matrix ◽  
Room Temperature ◽  
Fracture Analysis ◽  
Epoxy Composites ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Fiber Matrix Interface ◽  
Sisal Fibers

The tensile properties of DGEBA/TETA epoxy matrix composites reinforced with different amounts of sisal fibers were evaluated. Composites reinforce with up to 30% in volume of long, continuous and aligned sisal fibers were room temperature tested in an Instron machine. The fracture was analyzed by SEM. The results showed significant changes in the mechanical properties with the amount of sisal fibers. These mechanical properties were compared with other bend-tested composites results. The fracture analysis revealed a weak fiber/matrix interface, which could be responsible for the performance of some properties.

Evaluation of Mechanical Properties and Comprehensive Modeling of CMC with Stiff and Weak Matrices

2006 ◽  
Vol 45 ◽  
pp. 1435-1443 ◽  
Author(s):  
Dietmar Koch ◽  
Kamen Tushtev ◽  
Jürgen Horvath ◽  
Ralf Knoche ◽  
Georg Grathwohl
Keyword(s):  
Mechanical Properties ◽  
Mechanical Response ◽  
Ceramic Matrix Composites ◽  
High Strength ◽  
Shear Mode ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Strain Behavior ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The mechanical properties of ceramic matrix composites (CMC) depend on the individual properties of fibers and matrix, the fiber-matrix interface, the microstructure and the orientation of the fibers. The fiber-matrix interface of ceramics with stiff matrices (e.g. CVI-derived SiC/SiC) must be weak enough to allow crack deflection and debonding in order to achieve excellent strength and strain to failure (weak interface composites WIC). This micromechanical behavior has been intensively investigated during the last 20 years. With the development of CMC with weak matrices (weak matrix composites WMC) as e.g. oxide/oxide composites or polymer derived CMC the mechanical response can not be explained anymore by these models as other microstructural mechanisms occur. If the fibers are oriented in loading direction in a tensile test the WMC behave almost linear elastic up to failure and show a high strength. Under shear mode or if the fibers are oriented off axis a significant quasiplastic stress-strain behavior occurs with high strain to failure and low strength. This complex mechanical behavior of WMC will be explained using a finite element (FE) approach. The micromechanical as well as the FE models will be validated and attributed to the different manufacturing routes.

scholarly journals Multiscale Characterization of Nanoengineered Fiber-Reinforced Composites: Effect of Carbon Nanotubes on the Out-of-Plane Mechanical Behavior

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Carlos Medina ◽  
Eduardo Fernandez ◽  
Alexis Salas ◽  
Fernando Naya ◽  
Jon Molina-Aldereguía ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Shear Strength ◽  
Mechanical Behavior ◽  
Matrix Interface ◽  
Short Beam ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The mechanical properties of the matrix and the fiber/matrix interface have a relevant influence over the mechanical properties of a composite. In this work, a glass fiber-reinforced composite is manufactured using a carbon nanotubes (CNTs) doped epoxy matrix. The influence of the CNTs on the material mechanical behavior is evaluated on the resin, on the fiber/matrix interface, and on the composite. On resin, the incorporation of CNTs increased the hardness by 6% and decreased the fracture toughness by 17%. On the fiber/matrix interface, the interfacial shear strength (IFSS) increased by 22% for the nanoengineered composite (nFRC). The influence of the CNTs on the composite behavior was evaluated by through-thickness compression, short beam flexural, and intraply fracture tests. The compressive strength increased by 6% for the nFRC, attributed to the rise of the matrix hardness and the fiber/matrix IFSS. In contrast, the interlaminar shear strength (ILSS) obtained from the short beam tests was reduced by 8% for the nFRC; this is attributed to the detriment of the matrix fracture toughness. The intraply fracture test showed no significant influence of the CNTs on the fracture energy; however, the failure mode changed from brittle to ductile in the presence of the CNTs.

scholarly journals Fiber-matrix Interface Mechanical Properties of Carbon-Carbon Composites

2009 ◽  
Vol 7 (ists26) ◽  
pp. Pc_67-Pc_72 ◽  
Author(s):  
Ken GOTO ◽  
Miho ISHII ◽  
Hiroshi HATTA ◽  
Hitoshi KOHRI ◽  
Ichiro SHIOTA
Keyword(s):  
Mechanical Properties ◽  
Carbon Composites ◽  
Matrix Interface ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

scholarly journals A Review on Natural Fiber-Reinforced Geopolymer and Cement-Based Composites

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4603
Author(s):  
Marfa Camargo ◽  
Eyerusalem Adefrs Taye ◽  
Judith Roether ◽  
Daniel Tilahun Redda ◽  
Aldo Boccaccini
Keyword(s):  
New Technologies ◽  
Moisture Absorption ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Industrial Applications ◽  
Synthetic Fiber ◽  
Matrix Interface ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The use of ecological materials for building and industrial applications contributes to minimizing the environmental impact of new technologies. In this context, the cement and geopolymer sectors are considering natural fibers as sustainable reinforcement for developing composites. Natural fibers are renewable, biodegradable, and non-toxic, and they exhibit attractive mechanical properties in comparison with their synthetic fiber counterparts. However, their hydrophilic character makes them vulnerable to high volumes of moisture absorption, thus conferring poor wetting with the matrix and weakening the fiber–matrix interface. Therefore, modification and functionalization strategies for natural fibers to tailor interface properties and to improve the durability and mechanical behavior of cement and geopolymer-based composites become highly important. This paper presents a review of the physical, chemical and biological pre-treatments that have been performed on natural fibers, their results and effects on the fiber–matrix interface of cement and geopolymer composites. In addition, the degradation mechanisms of natural fibers used in such composites are discussed. This review finalizes with concluding remarks and recommendations to be addressed through further in-depth studies in the field.

Influence of Flax Fibers on Properties of Starch-Based Composites

2012 ◽  
Author(s):  
Hamdy Elsayed ◽  
Mahmoud Farag ◽  
Hassan Megahed ◽  
Sherif Mehanny
Keyword(s):  
Corn Starch ◽  
Weight Fraction ◽  
Thermoplastic Starch ◽  
Matrix Interface ◽  
Density Measurements ◽  
Flax Fibers ◽  
Strong Adhesion ◽  
Static Tensile ◽  
Fraction Increase ◽  
Fiber Matrix Interface

Eco-friendly “green” composites made from flax fibers and biodegradable corn starch-based matrix were successfully prepared by hot pressing. Thermoplastic starch (TPS) was obtained by blending native corn starch with glycerin and water. The plasticized starch was emulsified before being added to the previously NaOH-treated flax fibers. The flax content was varied from 20 to 80 wt%. The composites were preheated and then pressed at 5 MPa and 160°C for 30 minutes. Density measurements showed low porosity for all composites up to 50 wt% fibers. SEM investigation showed strong adhesion at fiber-matrix interface and good fibers wettability. Static tensile and flexural mechanical properties (stiffness and strength) of the composites appeared to increase with the fiber weight fraction increase up to 50 wt%. Increasing fiber content also improved composite stability in thermal degradation, water uptake and biodegradation. Some micromechanical models are used to study the tensile strength and modulus of the obtained composites such as the Kelly-Tyson and Halpin–Tsai equations. The present work shows that 50 wt% composite has competitive properties, qualifying this material to be affordable and appropriate for different applications.

Effects of Thermal Cycling on Properties of Carbon Fiber/Aluminum Composites

1988 ◽  
Vol 110 (2) ◽  
pp. 89-95 ◽  
Author(s):  
Tetsuyuki Kyono ◽  
Etsuro Kuroda ◽  
Atsushi Kitamura ◽  
Tsutomu Mori ◽  
Minoru Taya
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Thermal Cycling ◽  
Degradation Mechanism ◽  
Matrix Interface ◽  
Aluminum Composites ◽  
Longitudinal Tensile Strength ◽  
Casting Technique ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

Effects of thermal cycling on mechanical properties such as longitudinal tensile strength, interlaminar shear strength and work of fracture of carbon fiber/aluminum composites have been investigated. The composite specimens fabricated by a squeeze casting technique were thermally cycled in fluidized baths between room temperature and various temperatures (250, 300, and 350° C) for up to 1000 cycles. The cross sections and fracture surfaces were examined to clarify the degradation mechanism. Significant degradation of the mechanical properties by thermal cycling was observed in untreated carbon fiber/aluminum composites whereas much less degradation in surface treated carbon fiber/aluminum composites. Microscopic observations and short beam shear tests have indicated that the degradation of mechanical properties is caused by debonding at the fiber/matrix interface. The fiber/matrix interface for surface treated fiber was more resistant to debonding. It is concluded that thermal cycling damage of carbon fiber/aluminum composites can be minimized by increasing their fiber/matrix bond strengths.

Study of the Effect of Compatibility Agents in the Incorporation of Rice Hull Ash in Polypropylene Compounds: Mechanical Properties

2018 ◽  
Vol 930 ◽  
pp. 179-183
Author(s):  
Morgueto Natalia Oliveira ◽  
Nunes Edilene de Cássia Dutra ◽  
Nascimento Fernando Codelo ◽  
Saito Newton Haruo
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Coupling Agent ◽  
Rice Hull ◽  
Matrix Interface ◽  
Test Results ◽  
Rice Hull Ash ◽  
Material Stiffness ◽  
Excellent Adhesion

The present work aimed at incorporating the rice hull ash (RHA) into a polypropylene polymer matrix. The methodology applied was the case study, whereby the rice hull, residue generated during the grain extraction, was used in the present study. The samples were prepared with the addition of a coupling agent (silane) with 10% by mass in relation to the filler, to improve the characteristics of the ash/ matrix interface. The tensile test results showed that the modulus of elasticity increased proportionally to the addition of the RHA contents, promoting an increase in the material stiffness. The micrographs showed excellent adhesion between the RHA particles and the polymer matrix. proving the coupling, because there was a good wettability array load due to the use of the coupling agent. The results show the feasibility of use of CCA in the composite with PP.

Sign in / Sign up

Export Citation Format

Share Document