scholarly journals The Effects of Hybridisation of Composites Consisting of Aramid, Carbon, and Hemp Fibres in a Quasi-Static Penetration Test

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4686
Author(s):  
Joanna Pach ◽  
Natalia Frączek ◽  
Jacek Kaczmar
Keyword(s):  
Composite Laminates ◽  
Testing Machine ◽  
Damage Mechanism ◽  
Tensile Testing Machine ◽  
Static Penetration ◽  
Hemp Fibres ◽  
Hybrid Laminates ◽  
Aramid Fabrics ◽  
Penetration Tests ◽  
Carbon Fabrics

The quasi-static penetration properties of hybrid laminates were experimentally investigated. Aramid fabrics, carbon fabrics, and short hemp fibres were applied as the reinforcements of hybrid and non-hybrid composite laminates with polyurethane–polyurea (PUR/PUA) matrix. The laminates were made by hand, in a mould. They were cured at room temperature for 24 h. Hybrid laminates consisted of aramid and carbon layers in two different configurations, i.e., aramid at the innermost layers and outermost layers. Aramid/PUR/PUA and carbon/PUR/PUA composites were fabricated for comparison purposes. Laminates were also prepared via an analogue sequence of laying the reinforcement layers with the addition of 5% by weight of hemp fibres in the PUR/PUA matrix. Quasi-static penetration tests (QSPT) were conducted using a tensile testing machine with a surface-hardened, hemispherical, steel punch (9 mm diameter tip), reflecting the geometry of the Parabellum projectile. A quasi-static puncture test was carried out until the laminate was perforated. The ratio between the support span (Ds) and the punch diameter (Dp) was SPR = Ds/Dp = 5.0. The results showed the influences of laminate hybridisation on the values of absorbed energy, punch shear strength, and damage mechanism in the QSPT test. The addition of hemp fibres to aramid laminates resulted in a positive hybridisation effect. The order of layers of aramid and carbon fabrics in hybrid laminates influenced the results obtained in the QSPT test.

scholarly journals Investigation of the Quasi-Static Penetration Resistance Behaviour of Carbon/Aramid Fibre-Reinforced PP Laminate

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 709
Author(s):  
Joanna Pach ◽  
Ewa Kuterek
Keyword(s):  
Maximum Load ◽  
Damage Mechanism ◽  
Carbon Fibres ◽  
Penetration Test ◽  
Static Penetration ◽  
Intermediate Layers ◽  
Hybrid Laminates ◽  
Polypropylene Matrix ◽  
Outer Lining ◽  
The Impact

This work presents the experimental results of a quasi-static attempt at the penetration of hybrid and non-hybrid laminates reinforced with aramid and carbon fibres on a thermoplastic polypropylene matrix. The hybrid laminates were prepared in two fibre combinations: carbon–aramid–carbon (CAC), in which the carbon fibres comprised the outer (lining) layers, and aramid–carbon–aramid (ACA) with carbon fibres in their intermediate layers. A quasistatic penetration attempt was performed for two coefficients: SPR—support span to punch diameter ratio, (SPR = 2 and 5). The SPR = Ds/Dp was calculated as the ratio of the support (Ds) to the punch diameter (Dp). A punch with a rounded 9-mm diameter tip was used to penetrate the material. Percentage changes of penetration energy (%E) and of maximum load (%P) compared to a non-hybrid laminate with carbon fibres were calculated in order to estimate the impact of hybridisation on the properties of laminates. The maximum load recorded during a quasi-static penetration test was used to calculate the PSS (punch shear strength) of the laminates. The damage was observed after the penetration test. It was observed that both the order of layers of laminate reinforcement as well as the SPR coefficient used in the test influenced the obtained results and the laminate damage mechanism.

Experimental investigation on the double-position impact responses and damage mechanism for Z-pinned composite laminates

2021 ◽  
Vol 259 ◽  
pp. 113463
Author(s):  
Binbin Liao ◽  
Zhongwei Zhang ◽  
Liping Sun ◽  
Jianwu Zhou ◽  
Panding Wang ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Composite Laminates ◽  
Damage Mechanism ◽  
Impact Responses

Effect of Layering Sequence on Impact Properties of Alkali Treated Phoenix Pusilla Fibers-Glass-Carbon Fabrics Reinforced Hybrid Composite Laminates

2021 ◽  
pp. 1-11
Author(s):  
Madhu Puttegowda ◽  
Sanjay Mavinkere Rangappa ◽  
Anish Khan ◽  
Salma Ahmed Al-Zahrani ◽  
Ahmed Al Otaibi ◽  
...  
Keyword(s):  
Hybrid Composite ◽  
Composite Laminates ◽  
Impact Properties ◽  
Glass Carbon ◽  
Carbon Fabrics

scholarly journals The effect of frog pressure and downward vertical load on hoof wall weight-bearing and third phalanx displacement in the horse - an in vitro study : research communication

2001 ◽  
Vol 72 (4) ◽  
Author(s):  
A. Olivier ◽  
J. Wannenburg ◽  
R.D. Gottschalk ◽  
M.J. Van der Linde ◽  
H.T. Groeneveld
Keyword(s):  
Solar Surface ◽  
Weight Bearing ◽  
Testing Machine ◽  
Vertical Component ◽  
In Vitro Study ◽  
Vitro Study ◽  
Total Weight ◽  
Strain Gauges ◽  
Tensile Testing Machine

A shoe was designed to combine the advantages of a reverse shoe and an adjustable heart bar shoe in the treatment of chronic laminitis. This reverse even frog pressure (REFP) shoe applies pressure uniformly over a large area of the frog solar surface. Pressure is applied vertically upward parallel to the solar surface of the frog and can be increased or decreased as required. Five clinically healthy horses were humanely euthanased and their dismem-bered forelimbs used in an in vitro study. Frog pressure was measured by strain gauges applied to the ground surface of the carrying tab portion of the shoe. A linear variable distance transducer (LVDT) was inserted into a hole drilled in the dorsal hoof wall. The LVDT measured movement of the third phalanx (P3) in a dorsopalmar plane relative to the dorsal hoof wall. The vertical component of hoof wall compression was measured by means of unidirectional strain gauges attached to the toe, quarter and heel of the medial hoof wall of each specimen. The entire limb was mounted vertically in a tensile testing machine and submitted to vertical downward compressive forces of 0 to 2500 Nat a rate of 5 cm/minute. The effects of increasing frog pressure on hoof wall weight-bearing and third phalanx movement within the hoof were determined. Each specimen was tested with the shoe under the following conditions: zero frog pressure; frog pressure used to treat clinical cases of chronic laminitis (7 N-cm); frog pressure clinically painful to the horse as determined prior to euthanasia; frog pressure just alleviating this pain. The specimens were also tested after shoe removal. Total weight-bearing on the hoof wall at zero frog pressure was used as the basis for comparison. Pain-causing and pain-alleviating frog pressures decreased total weight-bearing on the hoof wall (P < 0.05). Frog pressure of 7 N-cm had no statistically significant effect on hoof wall weight-bearing although there was a trend for it to decrease as load increased. Before loading, the pain-causing and pain-alleviating frog pressures resulted in a palmar movement of P3 relative to the dorsal hoof wall compared to the position of P3 at zero frog pressure (P < 0.05). This difference remained statistically significant up to 1300 Nload. At higher loads, the position of P3 did not differ significantly for the different frog pressures applied. It is concluded that increased frog pressure using the REFP shoe decreases total hoof wall weight-bearing and causes palmar movement of P3 at low weight-bearing loads. Without a shoe the toe and quarter hoof wall compression remained more constant and less in magnitude, than with a shoe.

Use of a Durometer to Assess Onion Bulb Hardness

1978 ◽  
Vol 14 (3) ◽  
pp. 269-272 ◽  
Author(s):  
J. F. M. Fennell
Keyword(s):  
Tensile Testing ◽  
Test Procedure ◽  
Testing Machine ◽  
Onion Bulb ◽  
Tensile Testing Machine ◽  
Varietal Differences ◽  
Onion Bulbs ◽  
Non Destructive

SUMMARYThe use of a durometer to assess hardness of onion bulbs is described, and compared with the use of a tensile testing machine. Results from the two tests were closely correlated, and significant varietal differences were detected in bulb hardness by both machines. The durometer is of particular value because of the simplicity and non-destructive nature of the test procedure.

The Effects of Hydrothermal Ageing on the Crushing Behavior of Glass/Epoxy Composite Pipes

2015 ◽  
Vol 819 ◽  
pp. 411-416
Author(s):  
S.N. Fitriah ◽  
M.S. Abdul Majid ◽  
R. Daud ◽  
M. Afendi ◽  
Z.S. Nazirah
Keyword(s):  
Composite Laminates ◽  
Testing Machine ◽  
Hydrothermal Condition ◽  
Compression Tests ◽  
Universal Testing ◽  
Failure Region ◽  
The Matrix ◽  
Glass Fibre Reinforced ◽  
Crushing Behavior ◽  
Composite Pipes

The paper discusses the crushing behavior of glass fibre reinforced epoxy (GRE) pipes under hydrothermal ageing condition. This study determines the behavior of the GRE pipes when subjected to different ageing periods and temperatures. Hydrothermal ageing has been found to cause degradation between resin and fibre interface thus causing the reduction in the strength of composite laminates. The pipes were subjected to hydrothermal condition to simulate and precipitate ageing by immersing the pipe samples in water at 80°C for 250, 500, and 1000 hours. Compression tests were carried out using Universal Testing Machine (UTM) for virgin condition and aged samples in accordance with ASTM D695 standard. The maximum force at the initial failure region is observed for each of the conditioned pipes. The results show that the strength of the matrix systems was considerably degraded due to the plasticization of the matrix system.

Studies on Nanostructured Polyurethane/Clay Interpenetrating Polymer Networks

2005 ◽  
Vol 475-479 ◽  
pp. 1001-1004
Author(s):  
Ninglin Zhou ◽  
Xiao Xian Xia ◽  
Li Li ◽  
Shao Hua Wei ◽  
Jian Shen
Keyword(s):  
Mechanical Properties ◽  
Polymer Networks ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Interpenetrating Polymer Networks ◽  
Absorption Properties ◽  
Tensile Testing Machine ◽  
Swelling Agent ◽  
Silicate Layers ◽  
Polyurethane Matrix

A novel exfoliated polyurethane (PU)/clay Interpenetrating Polymer Networks (IPNs) nanocomposite has been synthesized with polyurethane and organoclay. MTPAC is used as swelling agent to treat Na-montmorillonite for forming organoclay. The results indicate that there is very good compatibility between organoclay and PU. Nanoscale silicate dispersion was analyzed by XRD. The mechanical properties of the nanocomposites have been measured by tensile testing machine. The nanocomposites show obviously improved physical and mechanical properties when compared with the pure polymer. Additionally, PU /MTPAC- clay shows lower water absorption properties than pure PU do. In addition, the reinforcing and intercalating mechanism of silicate layers in polyurethane matrix are discussed.

Mechanical and Barrier Properties of Polyvinyl Alcohol Films Modified with Carbon Nanotubes and Zinc Oxide

2021 ◽  
Vol 877 ◽  
pp. 27-33
Author(s):  
Ya Li Sun ◽  
Yi Hua Wen ◽  
Qing Cai Liu ◽  
Jui Chin Chen ◽  
Manual Reyes de Guzman ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Polyvinyl Alcohol ◽  
Nanocomposite Film ◽  
Testing Machine ◽  
Barrier Properties ◽  
X Ray Diffraction ◽  
Tensile Testing Machine ◽  
Solution Blending ◽  
Vapor Permeation ◽  
Property Measurement

A solution blending technique was employed to form a nanocomposite film of polyvinyl alcohol modified with carbon nanotube and zinc oxide (CNT/ZnO). The film was characterized using a tensile testing machine, X-ray diffraction, scanning electron microscopy, a contact angle device, and barrier property measurement. When the CNT/ZnO content was 1.2 phr, the results from mechanical property and water vapor permeation tests showed that the nanocomposite film had good tensile strength and water resistance. Moreover, CNT/ZnO improved the hydrophobicity of the film. CNT/ZnO/can improve the performance of PVA and is a good nanofiller of PVA. The results of this research might have the opportunity to be used as packaging film materials in the future.

Research of the Mechanical Properties of the Filament from the Percentage of Filling when Prototyping Machine Parts

2021 ◽  
Vol 410 ◽  
pp. 617-623
Author(s):  
Elena N. Gryadynova ◽  
Andrey V. Gorin ◽  
Alexey Yu. Rodichev
Keyword(s):  
Tensile Strength ◽  
Tensile Testing ◽  
Testing Machine ◽  
Experimental Studies ◽  
Relative Deformation ◽  
Strain Diagram ◽  
Experimental Sample ◽  
Tensile Testing Machine ◽  
Machine Parts ◽  
Fisher’S Criterion

The article contains the analysis of thermoplastics used in prototyping machine parts. We used several types of experimental samples with different filling percentages. The equipment on which the experimental studies were carried out is shown. During the experiment, a specialized tensile testing machine was used. The experimental samples were installed in the developed centering device. Normal conditions were observed during the tests. The results of an experimental tensile study of PLA-plastic specimens are presented. The typical stress-strain diagram of an experimental sample is described, which describes the dependence of stress on relative deformation. An equation of the linear dependence of the tensile strength on the percentage of filament filling has been compiled, which makes it possible to determine the tensile strength of the product at any percentage of the filling of the plastic filament. The assessment is adequately verified by Fisher's criterion. Recommendations for filament filling in prototyping machine parts are given.

EFFECTS OF NUMBER OF PLIES ON LIGHTNING STRIKE PROTECTION OF ELECTRICALLY CONDUCTIVE LAYER-WISE HYBRID LAMINATES

2021 ◽  
Author(s):  
SIWAT MANOMAISANTIPHAP ◽  
TOMOHIRO YOKOZEK YOKOZEKI
Keyword(s):  
Epoxy Resin ◽  
Composite Laminates ◽  
Bending Strength ◽  
Fuel Efficiency ◽  
Lightning Strike ◽  
Conductive Layer ◽  
Electrically Conductive ◽  
Hybrid Laminates ◽  
Conductive Polyaniline ◽  
Pani Layer

With the development of composite technologies, aircraft become lighter and more fuel efficiency. The composite aircraft, however, become susceptible to lightning strike. Developing lightning strike protection (LSP) system need to couple with composite technologies. The authors present a concept of LSP using layer-wise hybrid laminates (CF/Hybrid) in this study. The aim of the study is to validate the effectiveness of layer-wise hybrid laminates structure for lightning strike application by using conventional epoxy-resin CFRP for main structure and electrically conductive layer as a cover layer. The composite laminates include two different types of resin in each layer: conductive polyaniline-based matrix (CF/PANI) and conventional epoxy resin (CF/epoxy). CF/PANI layers varied from 1, 2, and 4 layers with corresponding 7, 6, and 4 layers of CF/epoxy to find out the least effective number of CF/PANI that can prevent lightning strike damage. The specimens were characterized for their mechanical properties and underwent simulated lightning strike test to realize their effectiveness. The result of simulated lightning strike has shown that a layer of conductive CF/PANI can help to avoid catastrophic damage on CF/epoxy. With a greater number of CF/PANI, the less detectable damage in CF/PANI layer became. In the case of CF/Hybrid with 4 layers of CF/PANI shows 70% residual bending strength after the lightning strike. With the aid of nondestructive inspection tools, i.e., thermography and ultrasonic test, the mechanism of damage on the composite panels were observed and analyzed. From this study, CF/Hybrid with 4 layers shows the optimal properties for lightning strike protection.

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