Influence of out-of-plane fiber waviness and different environmental conditionings on mechanical and morphological characteristics of fiber glass/epoxy laminates

2021 ◽  
pp. 002199832110476
Author(s):  
André Santiago Barros ◽  
Leonardo de Souza Vieira ◽  
Guilherme Ferreira de Melo Morgado ◽  
Erick Gabriel Ribeiro dos Anjos ◽  
Gabriel Portilho Monteiro de Souza ◽  
...  
Keyword(s):  
Saline Solution ◽  
Morphological Characteristics ◽  
Fiber Glass ◽  
Significant Deterioration ◽  
Fiber Waviness ◽  
Environmental Conditioning ◽  
Out Of Plane ◽  
The Matrix ◽  
Matrix Reinforcement ◽  
Degrees Of Severity

The use of structural polymeric composites constitutes an interesting option in the area of wind turbine blade manufacturing. Nevertheless, thick composite components may present out-of-plane waviness in their fibers, compromising the service life of the wind blades. In this context, the present study aims to study the influence of out-of-plane waviness in the fibers with different degrees of severity as well as to verify the effect of fiber glass/epoxy resin composites immersion in distilled water and saline solution in their tensile strength (σmax), modulus of elasticity (E), and deformation at break (єrup), analyzing the reinforcement/matrix interface changes. The results showed that the increase in severity promoted, in general, a statistically significant deterioration in σmax of the samples exposed to the same environmental conditioning. The conditioning led to a decrease in E and an increase in єrup, attributed to the deterioration of the interface and the plasticization of the polymeric matrix, respectively, as evidenced by fractographic analysis. The effect of severity on the єrup and σmax properties was only noticed in laminates exposed to environmental conditioning, due to water sorption favoring the deterioration of the matrix/reinforcement interface, intensifying the deleterious effect of out-of-plane waviness of fibers.

Analysis of High Velocity Impact on Composite Structures

2014 ◽  
Vol 617 ◽  
pp. 104-109 ◽  
Author(s):  
Milan Žmindák ◽  
Zoran Pelagić ◽  
Maroš Bvoc
Keyword(s):  
Carbon Fibers ◽  
Composite Structures ◽  
Impact Resistance ◽  
Leading Edge ◽  
Layered Composite ◽  
Bird Strike ◽  
Out Of Plane ◽  
The Matrix ◽  
Composite Wing ◽  
Considerable Damage

In the recent years a big focus is subjected to the response of structures subjected to out-of-plane loading such as blasts, impact, etc. not only to homogenous materials, but also to heterogeneous materials, such as composites. Such form of loading can cause considerable damage to the structure. In the case of layered composite materials the damage can have several forms, starting from damage in layers up to delamination and full damage of the construction. This paper describes the investigation of shockwave propagation in composite structures caused by impact loading. The composite consists of carbon fibers in a polymer matrix, in which the fibers are much stiffer then the matrix. Finite element simulations were carried out for a “bird” strike impact on a composite wing leading edge. Results show a good impact resistance and good damping abilities of shockwaves.

The Influence of Ultrasonic Energy on Chemical Treatment of Surface Properties and the Properties of Composites Made of Luffa Cylindrical Fiber-Polyester Resin

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
E. Dilara Koçak
Keyword(s):  
Composite Structure ◽  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Natural Fibers ◽  
Morphological Characteristics ◽  
Mechanical Tests ◽  
Cylindrical Fiber ◽  
The Matrix ◽  
Mechanical Performances ◽  
Properties Of Composites

Producing composites from natural fibers is known to be common. These fibers benefit from their mechanical performances, low density, and their biodegradability. However, it is necessary for the fibers to form adhesion in the matrix. Therefore, it is necessary to apply a chemical process to the surface of the fibers. In this study, four different processes in conventional and ultrasonic energies were applied on luffa cylindrical fibers. At the end of the application, a composite structure was formed on the fibers that were obtained by using unsaturated polyester resin. The changes in the characteristics of the composite structure were recorded by mechanical tests, Fourier transform infrared, X-ray diffractometer, and their morphological characteristics by means of scanning electron microscopy. Considering all the results, formic acid and acetic acid process results were found to adequately modify the fiber surfaces.

scholarly journals Connected Lead Zirconate Titanate Nanodot Arrays for Perspective Functional Materials

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
M. Waegner ◽  
A. Finn ◽  
G. Suchaneck ◽  
G. Gerlach ◽  
L. M. Eng
Keyword(s):  
Lead Zirconate Titanate ◽  
Short Circuit ◽  
Functional Materials ◽  
Piezoresponse Force Microscopy ◽  
Lead Zirconate ◽  
Lateral Direction ◽  
Flexible Polymer ◽  
Zirconate Titanate ◽  
Out Of Plane ◽  
The Matrix

We describe the fabrication of lead zirconate titanate (PZT) nanodisc arrays isolated by a polymer layer and contacted with a top electrode. PZT thin films were deposited by multitarget sputtering onto a platinum/titanium bottom electrode and structured by means of nanosphere lithography. To guarantee short-circuit-free deposition of a top electrode, the space between the nanostructures was filled by a polymer. Two approaches for the filling are demonstrated: (a) imprinting and (b) skim coating. Single nanodiscs embedded in a flexible polymer matrix have two major advantages. First, taking into account the flexibility of the matrix, they can vibrate in lateral direction and, second, due to shrinking to the nanoscale, predominant directions of the polarization form, such as vortex- or bubble-like domain patterns. Piezoresponse force microscopy was performed on patterned and nonpatterned samples with and without a top electrode to check the local piezoresponse. Comparison of the different samples revealed an increase in lateral piezoactivity for patterned samples with Ni/Cr electrode while the out-of-plane piezoresponse remained constant. Gold electrodes limit the piezoresponse in both measured directions.

Toughness of ECC Evaluated by Nominal Fracture Energy

2012 ◽  
Vol 238 ◽  
pp. 57-60 ◽  
Author(s):  
Shu Ling Gao ◽  
Wei Shao ◽  
Jin Li Qiao ◽  
Ling Wang
Keyword(s):  
Glass Fiber ◽  
Fracture Energy ◽  
Steel Fiber ◽  
Volume Ratio ◽  
Fiber Glass ◽  
Fiber Volume ◽  
High Durability ◽  
The Matrix ◽  
Pva Fiber ◽  
Very High

ECC (Engineered Cementitious Composites) has ultra-high toughness and can be used in the zone needing the ultra-high tensile strain and very high durability. In order to investigate the toughness of ECC, the normal fracture energy GFis calculated and compared with ordinary concrete. The influence of the matrix (fly ash, silicon fume), the fiber (glass fiber, steel fiber and PVA fiber) and the fiber volume ratio on the GFof ECC are analyzed. The research indicates that silicon fume and glass fiber, steel fiber are all not able to be used in ECC. But flash ash and PVA fiber are very suit for using in ECC, the toughness of ECC increases with the increase of their content.

Modeling and experimental investigation of out-of-plane deformation on mechanical performance of composites manufactured by ATL

2016 ◽  
Vol 36 (5) ◽  
pp. 347-359 ◽  
Author(s):  
Qiyi Chu ◽  
Yong Li ◽  
Jun Xiao ◽  
Dajun Huan ◽  
Xiaodong Chen
Keyword(s):  
Tensile Strength ◽  
Deformation Rate ◽  
Mechanical Performance ◽  
Plane Deformation ◽  
Experimental Results ◽  
Predicting Model ◽  
Fiber Waviness ◽  
Manufacturing Method ◽  
Four Point Bending ◽  
Out Of Plane

The change of mold normal curvature along the trajectory may result in out-of-plane waviness during the automated laying process, on which the layup speed and temperature would have an effect. A new parameter, deformation rate, was defined by combining the effect of mold curvature change rate and layup speed. A predicting model was proposed based on the fiber waviness and interlaminar sliding model to calculate the relationship between stiffness retention and the layup process parameters, including deformation rate and temperature. An experimental study on the effect of different deformation parameters on the tensile performance of composites was carried out based on a new manufacturing method of plated specimens with different levels of waviness by means of a four-point bending fixture. The experimental results showed that when the deformation temperature increases from 20℃ to 80℃, the tensile strength increases first and then decreases while the tensile module keeps increasing. While the deformation rate decreases from 0.40 to 0.04 mm−1/s, both tensile strength and module showed an increasing trend. The predicting model being validated by experimental results can be utilized to optimize the layup process parameter to satisfy the quality and efficiency requirements.

scholarly journals Morphological Evolutions of Ni-Rich Phases in Al-Si Piston Alloys during 250–400 °C Thermal Exposure Processes

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5212
Author(s):  
Haowei An ◽  
Jiwei Geng ◽  
Zeyu Bian ◽  
Gen Liu ◽  
Mingliang Wang ◽  
...  
Keyword(s):  
Morphological Evolution ◽  
Morphological Characteristics ◽  
Hardness Test ◽  
Thermal Exposure ◽  
Micro Hardness ◽  
Morphological Transformation ◽  
Alloy Hardness ◽  
The Matrix ◽  
Hardness Increase ◽  
Exposure Process

The thermal stability of the Al-Si alloys during the thermal exposure process from 250 °C to 400 °C was systematically investigated. The relationships between the morphological evolution and the mechanical changes of the alloys were determined through the Vickers hardness test and materials characterization method. Initially, the alloys exhibited similar thermal degradation behavior. For example, the exposure process of the alloy at 300 °C can be divided into two stages according to the changes of the alloy hardness and the matrix micro-hardness. In detail, the first stage (0–2 h) exhibited a severe reduction of the alloy hardness while the second stage showed a more leveled hardness during the following 98 h. There are three identified morphological characteristics of Ni-rich phases in the alloy. Furthermore, the differences in both composition and the micro-hardness between these Ni-rich phases were confirmed. The underlying relationships between the morphological transformation of the Ni-rich phases and hardness fluctuation in the alloy were correlated and elucidated. The observed alloy hardness increase when the exposure temperature was 400 °C was unexpected. This behavior was explained from the perspectives of both Ni-rich phases evolution and dispersoid formation.

The Effect of Glass Chemistry on the Microstructub and Properties of Self Reinforced Silicon Nitride

1992 ◽  
Vol 287 ◽  
Author(s):  
Aleksander J. Pyzik ◽  
Daniel F. Carroll ◽  
C. James Hwang
Keyword(s):  
Silicon Nitride ◽  
Glass Matrix ◽  
Glassy Phase ◽  
Large Degree ◽  
Sufficient Condition ◽  
Flexure Strength ◽  
Maximum Flexure ◽  
The Matrix ◽  
Matrix Reinforcement

ABSTRACTThe advantage of self-reinforced silicon nitride is the in-situ control of the microstructure. This control is provided in large degree by the chemistry of glassy phase which can be adjusted to tailor the morphology of silicon nitride grains as well as the matrix - reinforcement interface. The presence of high aspect ratio silicon nitride grains is necessary but not sufficient condition to produce materials with optimum properties. For maximum flexure strength and fracture toughness an optimized glass matrix is required.

Preparation and Adsorption Performance of GF/EPDM/LLDPE Foaming Composite for Petrol

2012 ◽  
Vol 602-604 ◽  
pp. 1157-1160
Author(s):  
Xiu Qi Liu ◽  
He Qin Xing ◽  
Li Li Zhao ◽  
Dan Wang
Keyword(s):  
Absorption Rate ◽  
Cell Structure ◽  
Oil Absorption ◽  
Melt Blending ◽  
Adsorption Performance ◽  
Internal Cell ◽  
Foam Composite ◽  
The Matrix ◽  
Long Time ◽  
Matrix Reinforcement

In our study, a new kind of material for petrol adsorption was prepared by melt blending and molding foaming with EPDM and LLDPE as the matrix and modified glass fiber (GF) as the filler. LLDPE as the second matrix can improve the matrix reinforcement, the composite cross-linked network density was reduced, but the oil absorption rate was increasing. After recycling three times, the oil absorption rate GF/EPDM foaming composite and GF / LLDPE / EPDM foam composite were changed little, the internal cell structure can exist for a long time and showed good recycling performance.

Sign in / Sign up

Export Citation Format

Share Document